Upgrade rust/crates/grpcio-sys to 0.8.1

Test: make
Change-Id: I333e35e7d00abaa92ea6beb00e9cf5b85840998f

58 files changed, 6454 insertions, 0 deletions

diff --git a/grpc/spm-core-include/grpc/byte_buffer.h b/grpc/spm-core-include/grpc/byte_buffer.h
new file mode 100644
index 00000000..ee740f47
--- /dev/null
+++ b/grpc/spm-core-include/grpc/byte_buffer.h
@@ -0,0 +1,27 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_BYTE_BUFFER_H
+#define GRPC_BYTE_BUFFER_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/byte_buffer.h>
+#include <grpc/slice_buffer.h>
+
+#endif /* GRPC_BYTE_BUFFER_H */
diff --git a/grpc/spm-core-include/grpc/byte_buffer_reader.h b/grpc/spm-core-include/grpc/byte_buffer_reader.h
new file mode 100644
index 00000000..15e06cad
--- /dev/null
+++ b/grpc/spm-core-include/grpc/byte_buffer_reader.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_BYTE_BUFFER_READER_H
+#define GRPC_BYTE_BUFFER_READER_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/byte_buffer_reader.h>
+
+#endif /* GRPC_BYTE_BUFFER_READER_H */
diff --git a/grpc/spm-core-include/grpc/census.h b/grpc/spm-core-include/grpc/census.h
new file mode 100644
index 00000000..4894f1c0
--- /dev/null
+++ b/grpc/spm-core-include/grpc/census.h
@@ -0,0 +1,40 @@
+/*
+ *
+ * Copyright 2015-2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CENSUS_H
+#define GRPC_CENSUS_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/grpc.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+  A Census Context is a handle used by Census to represent the current tracing
+  and stats collection information. Contexts should be propagated across RPC's
+  (this is the responsibility of the local RPC system). */
+typedef struct census_context census_context;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CENSUS_H */
diff --git a/grpc/spm-core-include/grpc/compression.h b/grpc/spm-core-include/grpc/compression.h
new file mode 100644
index 00000000..17695664
--- /dev/null
+++ b/grpc/spm-core-include/grpc/compression.h
@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_COMPRESSION_H
+#define GRPC_COMPRESSION_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <stdlib.h>
+
+#include <grpc/impl/codegen/compression_types.h>
+#include <grpc/slice.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Return if an algorithm is message compression algorithm. */
+GRPCAPI int grpc_compression_algorithm_is_message(
+    grpc_compression_algorithm algorithm);
+
+/** Return if an algorithm is stream compression algorithm. */
+GRPCAPI int grpc_compression_algorithm_is_stream(
+    grpc_compression_algorithm algorithm);
+
+/** Parses the \a slice as a grpc_compression_algorithm instance and updating \a
+ * algorithm. Returns 1 upon success, 0 otherwise. */
+GRPCAPI int grpc_compression_algorithm_parse(
+    grpc_slice name, grpc_compression_algorithm* algorithm);
+
+/** Updates \a name with the encoding name corresponding to a valid \a
+ * algorithm. Note that \a name is statically allocated and must *not* be freed.
+ * Returns 1 upon success, 0 otherwise. */
+GRPCAPI int grpc_compression_algorithm_name(
+    grpc_compression_algorithm algorithm, const char** name);
+
+/** Returns the compression algorithm corresponding to \a level for the
+ * compression algorithms encoded in the \a accepted_encodings bitset.*/
+GRPCAPI grpc_compression_algorithm grpc_compression_algorithm_for_level(
+    grpc_compression_level level, uint32_t accepted_encodings);
+
+GRPCAPI void grpc_compression_options_init(grpc_compression_options* opts);
+
+/** Mark \a algorithm as enabled in \a opts. */
+GRPCAPI void grpc_compression_options_enable_algorithm(
+    grpc_compression_options* opts, grpc_compression_algorithm algorithm);
+
+/** Mark \a algorithm as disabled in \a opts. */
+GRPCAPI void grpc_compression_options_disable_algorithm(
+    grpc_compression_options* opts, grpc_compression_algorithm algorithm);
+
+/** Returns true if \a algorithm is marked as enabled in \a opts. */
+GRPCAPI int grpc_compression_options_is_algorithm_enabled(
+    const grpc_compression_options* opts, grpc_compression_algorithm algorithm);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_COMPRESSION_H */
diff --git a/grpc/spm-core-include/grpc/fork.h b/grpc/spm-core-include/grpc/fork.h
new file mode 100644
index 00000000..26f9df98
--- /dev/null
+++ b/grpc/spm-core-include/grpc/fork.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_FORK_H
+#define GRPC_FORK_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/fork.h>
+
+#endif /* GRPC_FORK_H */
diff --git a/grpc/spm-core-include/grpc/grpc.h b/grpc/spm-core-include/grpc/grpc.h
new file mode 100644
index 00000000..09bb1061
--- /dev/null
+++ b/grpc/spm-core-include/grpc/grpc.h
@@ -0,0 +1,548 @@
+/*
+ *
+ * Copyright 2015-2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_GRPC_H
+#define GRPC_GRPC_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/status.h>
+
+#include <grpc/byte_buffer.h>
+#include <grpc/impl/codegen/connectivity_state.h>
+#include <grpc/impl/codegen/grpc_types.h>
+#include <grpc/impl/codegen/propagation_bits.h>
+#include <grpc/slice.h>
+#include <grpc/support/time.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*! \mainpage GRPC Core
+ *
+ * The GRPC Core library is a low-level library designed to be wrapped by higher
+ * level libraries. The top-level API is provided in grpc.h. Security related
+ * functionality lives in grpc_security.h.
+ */
+
+GRPCAPI void grpc_metadata_array_init(grpc_metadata_array* array);
+GRPCAPI void grpc_metadata_array_destroy(grpc_metadata_array* array);
+
+GRPCAPI void grpc_call_details_init(grpc_call_details* details);
+GRPCAPI void grpc_call_details_destroy(grpc_call_details* details);
+
+/** Registers a plugin to be initialized and destroyed with the library.
+
+    The \a init and \a destroy functions will be invoked as part of
+    \a grpc_init() and \a grpc_shutdown(), respectively.
+    Note that these functions can be invoked an arbitrary number of times
+    (and hence so will \a init and \a destroy).
+    It is safe to pass NULL to either argument. Plugins are destroyed in
+    the reverse order they were initialized. */
+GRPCAPI void grpc_register_plugin(void (*init)(void), void (*destroy)(void));
+
+/** Initialize the grpc library.
+
+    After it's called, a matching invocation to grpc_shutdown() is expected.
+
+    It is not safe to call any other grpc functions before calling this.
+    (To avoid overhead, little checking is done, and some things may work. We
+    do not warrant that they will continue to do so in future revisions of this
+    library). */
+GRPCAPI void grpc_init(void);
+
+/** Shut down the grpc library.
+
+    Before it's called, there should haven been a matching invocation to
+    grpc_init().
+
+    The last call to grpc_shutdown will initiate cleaning up of grpc library
+    internals, which can happen in another thread. Once the clean-up is done,
+    no memory is used by grpc, nor are any instructions executing within the
+    grpc library.  Prior to calling, all application owned grpc objects must
+    have been destroyed. */
+GRPCAPI void grpc_shutdown(void);
+
+/** EXPERIMENTAL. Returns 1 if the grpc library has been initialized.
+    TODO(ericgribkoff) Decide if this should be promoted to non-experimental as
+    part of stabilizing the fork support API, as tracked in
+    https://github.com/grpc/grpc/issues/15334 */
+GRPCAPI int grpc_is_initialized(void);
+
+/** DEPRECATED. Recommend to use grpc_shutdown only */
+GRPCAPI void grpc_shutdown_blocking(void);
+
+/** Return a string representing the current version of grpc */
+GRPCAPI const char* grpc_version_string(void);
+
+/** Return a string specifying what the 'g' in gRPC stands for */
+GRPCAPI const char* grpc_g_stands_for(void);
+
+/** Returns the completion queue factory based on the attributes. MAY return a
+    NULL if no factory can be found */
+GRPCAPI const grpc_completion_queue_factory*
+grpc_completion_queue_factory_lookup(
+    const grpc_completion_queue_attributes* attributes);
+
+/** Helper function to create a completion queue with grpc_cq_completion_type
+    of GRPC_CQ_NEXT and grpc_cq_polling_type of GRPC_CQ_DEFAULT_POLLING */
+GRPCAPI grpc_completion_queue* grpc_completion_queue_create_for_next(
+    void* reserved);
+
+/** Helper function to create a completion queue with grpc_cq_completion_type
+    of GRPC_CQ_PLUCK and grpc_cq_polling_type of GRPC_CQ_DEFAULT_POLLING */
+GRPCAPI grpc_completion_queue* grpc_completion_queue_create_for_pluck(
+    void* reserved);
+
+/** Helper function to create a completion queue with grpc_cq_completion_type
+    of GRPC_CQ_CALLBACK and grpc_cq_polling_type of GRPC_CQ_DEFAULT_POLLING.
+    This function is experimental. */
+GRPCAPI grpc_completion_queue* grpc_completion_queue_create_for_callback(
+    grpc_experimental_completion_queue_functor* shutdown_callback,
+    void* reserved);
+
+/** Create a completion queue */
+GRPCAPI grpc_completion_queue* grpc_completion_queue_create(
+    const grpc_completion_queue_factory* factory,
+    const grpc_completion_queue_attributes* attributes, void* reserved);
+
+/** Blocks until an event is available, the completion queue is being shut down,
+    or deadline is reached.
+
+    Returns a grpc_event with type GRPC_QUEUE_TIMEOUT on timeout,
+    otherwise a grpc_event describing the event that occurred.
+
+    Callers must not call grpc_completion_queue_next and
+    grpc_completion_queue_pluck simultaneously on the same completion queue. */
+GRPCAPI grpc_event grpc_completion_queue_next(grpc_completion_queue* cq,
+                                              gpr_timespec deadline,
+                                              void* reserved);
+
+/** Blocks until an event with tag 'tag' is available, the completion queue is
+    being shutdown or deadline is reached.
+
+    Returns a grpc_event with type GRPC_QUEUE_TIMEOUT on timeout,
+    otherwise a grpc_event describing the event that occurred.
+
+    Callers must not call grpc_completion_queue_next and
+    grpc_completion_queue_pluck simultaneously on the same completion queue.
+
+    Completion queues support a maximum of GRPC_MAX_COMPLETION_QUEUE_PLUCKERS
+    concurrently executing plucks at any time. */
+GRPCAPI grpc_event grpc_completion_queue_pluck(grpc_completion_queue* cq,
+                                               void* tag, gpr_timespec deadline,
+                                               void* reserved);
+
+/** Maximum number of outstanding grpc_completion_queue_pluck executions per
+    completion queue */
+#define GRPC_MAX_COMPLETION_QUEUE_PLUCKERS 6
+
+/** Begin destruction of a completion queue. Once all possible events are
+    drained then grpc_completion_queue_next will start to produce
+    GRPC_QUEUE_SHUTDOWN events only. At that point it's safe to call
+    grpc_completion_queue_destroy.
+
+    After calling this function applications should ensure that no
+    NEW work is added to be published on this completion queue. */
+GRPCAPI void grpc_completion_queue_shutdown(grpc_completion_queue* cq);
+
+/** Destroy a completion queue. The caller must ensure that the queue is
+    drained and no threads are executing grpc_completion_queue_next */
+GRPCAPI void grpc_completion_queue_destroy(grpc_completion_queue* cq);
+
+/*********** EXPERIMENTAL API ************/
+/** Initializes a thread local cache for \a cq.
+ * grpc_flush_cq_tls_cache() MUST be called on the same thread,
+ * with the same cq.
+ */
+GRPCAPI void grpc_completion_queue_thread_local_cache_init(
+    grpc_completion_queue* cq);
+
+/*********** EXPERIMENTAL API ************/
+/** Flushes the thread local cache for \a cq.
+ * Returns 1 if there was contents in the cache.  If there was an event
+ * in \a cq tls cache, its tag is placed in tag, and ok is set to the
+ * event success.
+ */
+GRPCAPI int grpc_completion_queue_thread_local_cache_flush(
+    grpc_completion_queue* cq, void** tag, int* ok);
+
+/** Check the connectivity state of a channel. */
+GRPCAPI grpc_connectivity_state grpc_channel_check_connectivity_state(
+    grpc_channel* channel, int try_to_connect);
+
+/** Number of active "external connectivity state watchers" attached to a
+ * channel.
+ * Useful for testing. **/
+GRPCAPI int grpc_channel_num_external_connectivity_watchers(
+    grpc_channel* channel);
+
+/** Watch for a change in connectivity state.
+    Once the channel connectivity state is different from last_observed_state,
+    tag will be enqueued on cq with success=1.
+    If deadline expires BEFORE the state is changed, tag will be enqueued on cq
+    with success=0. */
+GRPCAPI void grpc_channel_watch_connectivity_state(
+    grpc_channel* channel, grpc_connectivity_state last_observed_state,
+    gpr_timespec deadline, grpc_completion_queue* cq, void* tag);
+
+/** Check whether a grpc channel supports connectivity watcher */
+GRPCAPI int grpc_channel_support_connectivity_watcher(grpc_channel* channel);
+
+/** Create a call given a grpc_channel, in order to call 'method'. All
+    completions are sent to 'completion_queue'. 'method' and 'host' need only
+    live through the invocation of this function.
+    If parent_call is non-NULL, it must be a server-side call. It will be used
+    to propagate properties from the server call to this new client call,
+    depending on the value of \a propagation_mask (see propagation_bits.h for
+    possible values). */
+GRPCAPI grpc_call* grpc_channel_create_call(
+    grpc_channel* channel, grpc_call* parent_call, uint32_t propagation_mask,
+    grpc_completion_queue* completion_queue, grpc_slice method,
+    const grpc_slice* host, gpr_timespec deadline, void* reserved);
+
+/** Pre-register a method/host pair on a channel.
+    method and host are not owned and must remain alive while the channel is
+    alive. */
+GRPCAPI void* grpc_channel_register_call(grpc_channel* channel,
+                                         const char* method, const char* host,
+                                         void* reserved);
+
+/** Create a call given a handle returned from grpc_channel_register_call.
+    \sa grpc_channel_create_call. */
+GRPCAPI grpc_call* grpc_channel_create_registered_call(
+    grpc_channel* channel, grpc_call* parent_call, uint32_t propagation_mask,
+    grpc_completion_queue* completion_queue, void* registered_call_handle,
+    gpr_timespec deadline, void* reserved);
+
+/** Allocate memory in the grpc_call arena: this memory is automatically
+    discarded at call completion */
+GRPCAPI void* grpc_call_arena_alloc(grpc_call* call, size_t size);
+
+/** Start a batch of operations defined in the array ops; when complete, post a
+    completion of type 'tag' to the completion queue bound to the call.
+    The order of ops specified in the batch has no significance.
+    Only one operation of each type can be active at once in any given
+    batch.
+    If a call to grpc_call_start_batch returns GRPC_CALL_OK you must call
+    grpc_completion_queue_next or grpc_completion_queue_pluck on the completion
+    queue associated with 'call' for work to be performed. If a call to
+    grpc_call_start_batch returns any value other than GRPC_CALL_OK it is
+    guaranteed that no state associated with 'call' is changed and it is not
+    appropriate to call grpc_completion_queue_next or
+    grpc_completion_queue_pluck consequent to the failed grpc_call_start_batch
+    call.
+    If a call to grpc_call_start_batch with an empty batch returns
+    GRPC_CALL_OK, the tag is put in the completion queue immediately.
+    THREAD SAFETY: access to grpc_call_start_batch in multi-threaded environment
+    needs to be synchronized. As an optimization, you may synchronize batches
+    containing just send operations independently from batches containing just
+    receive operations. Access to grpc_call_start_batch with an empty batch is
+    thread-compatible. */
+GRPCAPI grpc_call_error grpc_call_start_batch(grpc_call* call,
+                                              const grpc_op* ops, size_t nops,
+                                              void* tag, void* reserved);
+
+/** Returns a newly allocated string representing the endpoint to which this
+    call is communicating with. The string is in the uri format accepted by
+    grpc_channel_create.
+    The returned string should be disposed of with gpr_free().
+
+    WARNING: this value is never authenticated or subject to any security
+    related code. It must not be used for any authentication related
+    functionality. Instead, use grpc_auth_context. */
+GRPCAPI char* grpc_call_get_peer(grpc_call* call);
+
+struct census_context;
+
+/** Set census context for a call; Must be called before first call to
+   grpc_call_start_batch(). */
+GRPCAPI void grpc_census_call_set_context(grpc_call* call,
+                                          struct census_context* context);
+
+/** Retrieve the calls current census context. */
+GRPCAPI struct census_context* grpc_census_call_get_context(grpc_call* call);
+
+/** Return a newly allocated string representing the target a channel was
+    created for. */
+GRPCAPI char* grpc_channel_get_target(grpc_channel* channel);
+
+/** Request info about the channel.
+    \a channel_info indicates what information is being requested and
+    how that information will be returned.
+    \a channel_info is owned by the caller. */
+GRPCAPI void grpc_channel_get_info(grpc_channel* channel,
+                                   const grpc_channel_info* channel_info);
+
+/** EXPERIMENTAL.  Resets the channel's connect backoff.
+    TODO(roth): When we see whether this proves useful, either promote
+    to non-experimental or remove it. */
+GRPCAPI void grpc_channel_reset_connect_backoff(grpc_channel* channel);
+
+/** Create a client channel to 'target'. Additional channel level configuration
+    MAY be provided by grpc_channel_args, though the expectation is that most
+    clients will want to simply pass NULL. The user data in 'args' need only
+    live through the invocation of this function. However, if any args of the
+    'pointer' type are passed, then the referenced vtable must be maintained
+    by the caller until grpc_channel_destroy terminates. See grpc_channel_args
+    definition for more on this. */
+GRPCAPI grpc_channel* grpc_insecure_channel_create(
+    const char* target, const grpc_channel_args* args, void* reserved);
+
+/** Create a lame client: this client fails every operation attempted on it. */
+GRPCAPI grpc_channel* grpc_lame_client_channel_create(
+    const char* target, grpc_status_code error_code, const char* error_message);
+
+/** Close and destroy a grpc channel */
+GRPCAPI void grpc_channel_destroy(grpc_channel* channel);
+
+/** Error handling for grpc_call
+   Most grpc_call functions return a grpc_error. If the error is not GRPC_OK
+   then the operation failed due to some unsatisfied precondition.
+   If a grpc_call fails, it's guaranteed that no change to the call state
+   has been made. */
+
+/** Cancel an RPC.
+    Can be called multiple times, from any thread.
+    THREAD-SAFETY grpc_call_cancel and grpc_call_cancel_with_status
+    are thread-safe, and can be called at any point before grpc_call_unref
+    is called.*/
+GRPCAPI grpc_call_error grpc_call_cancel(grpc_call* call, void* reserved);
+
+/** Cancel an RPC.
+    Can be called multiple times, from any thread.
+    If a status has not been received for the call, set it to the status code
+    and description passed in.
+    Importantly, this function does not send status nor description to the
+    remote endpoint.
+    Note that \a description doesn't need be a static string.
+    It doesn't need to be alive after the call to
+    grpc_call_cancel_with_status completes.
+    */
+GRPCAPI grpc_call_error grpc_call_cancel_with_status(grpc_call* call,
+                                                     grpc_status_code status,
+                                                     const char* description,
+                                                     void* reserved);
+
+/** Ref a call.
+    THREAD SAFETY: grpc_call_ref is thread-compatible */
+GRPCAPI void grpc_call_ref(grpc_call* call);
+
+/** Unref a call.
+    THREAD SAFETY: grpc_call_unref is thread-compatible */
+GRPCAPI void grpc_call_unref(grpc_call* call);
+
+/** Request notification of a new call.
+    Once a call is received, a notification tagged with \a tag_new is added to
+    \a cq_for_notification. \a call, \a details and \a request_metadata are
+    updated with the appropriate call information. \a cq_bound_to_call is bound
+    to \a call, and batch operation notifications for that call will be posted
+    to \a cq_bound_to_call.
+    Note that \a cq_for_notification must have been registered to the server via
+    \a grpc_server_register_completion_queue. */
+GRPCAPI grpc_call_error grpc_server_request_call(
+    grpc_server* server, grpc_call** call, grpc_call_details* details,
+    grpc_metadata_array* request_metadata,
+    grpc_completion_queue* cq_bound_to_call,
+    grpc_completion_queue* cq_for_notification, void* tag_new);
+
+/** How to handle payloads for a registered method */
+typedef enum {
+  /** Don't try to read the payload */
+  GRPC_SRM_PAYLOAD_NONE,
+  /** Read the initial payload as a byte buffer */
+  GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER
+} grpc_server_register_method_payload_handling;
+
+/** Registers a method in the server.
+    Methods to this (host, method) pair will not be reported by
+    grpc_server_request_call, but instead be reported by
+    grpc_server_request_registered_call when passed the appropriate
+    registered_method (as returned by this function).
+    Must be called before grpc_server_start.
+    Returns NULL on failure. */
+GRPCAPI void* grpc_server_register_method(
+    grpc_server* server, const char* method, const char* host,
+    grpc_server_register_method_payload_handling payload_handling,
+    uint32_t flags);
+
+/** Request notification of a new pre-registered call. 'cq_for_notification'
+    must have been registered to the server via
+    grpc_server_register_completion_queue. */
+GRPCAPI grpc_call_error grpc_server_request_registered_call(
+    grpc_server* server, void* registered_method, grpc_call** call,
+    gpr_timespec* deadline, grpc_metadata_array* request_metadata,
+    grpc_byte_buffer** optional_payload,
+    grpc_completion_queue* cq_bound_to_call,
+    grpc_completion_queue* cq_for_notification, void* tag_new);
+
+/** Create a server. Additional configuration for each incoming channel can
+    be specified with args. If no additional configuration is needed, args can
+    be NULL. The user data in 'args' need only live through the invocation of
+    this function. However, if any args of the 'pointer' type are passed, then
+    the referenced vtable must be maintained by the caller until
+    grpc_server_destroy terminates. See grpc_channel_args definition for more
+    on this. */
+GRPCAPI grpc_server* grpc_server_create(const grpc_channel_args* args,
+                                        void* reserved);
+
+/** Register a completion queue with the server. Must be done for any
+    notification completion queue that is passed to grpc_server_request_*_call
+    and to grpc_server_shutdown_and_notify. Must be performed prior to
+    grpc_server_start. */
+GRPCAPI void grpc_server_register_completion_queue(grpc_server* server,
+                                                   grpc_completion_queue* cq,
+                                                   void* reserved);
+
+typedef struct grpc_server_config_fetcher grpc_server_config_fetcher;
+
+/** EXPERIMENTAL.  Creates an xDS config fetcher. */
+GRPCAPI grpc_server_config_fetcher* grpc_server_config_fetcher_xds_create();
+
+/** EXPERIMENTAL.  Destroys a config fetcher. */
+GRPCAPI void grpc_server_config_fetcher_destroy(
+    grpc_server_config_fetcher* config_fetcher);
+
+/** EXPERIMENTAL.  Sets the server's config fetcher.  Takes ownership.
+    Must be called before adding ports */
+GRPCAPI void grpc_server_set_config_fetcher(
+    grpc_server* server, grpc_server_config_fetcher* config_fetcher);
+
+/** Add a HTTP2 over plaintext over tcp listener.
+    Returns bound port number on success, 0 on failure.
+    REQUIRES: server not started */
+GRPCAPI int grpc_server_add_insecure_http2_port(grpc_server* server,
+                                                const char* addr);
+
+/** Start a server - tells all listeners to start listening */
+GRPCAPI void grpc_server_start(grpc_server* server);
+
+/** Begin shutting down a server.
+    After completion, no new calls or connections will be admitted.
+    Existing calls will be allowed to complete.
+    Send a GRPC_OP_COMPLETE event when there are no more calls being serviced.
+    Shutdown is idempotent, and all tags will be notified at once if multiple
+    grpc_server_shutdown_and_notify calls are made. 'cq' must have been
+    registered to this server via grpc_server_register_completion_queue. */
+GRPCAPI void grpc_server_shutdown_and_notify(grpc_server* server,
+                                             grpc_completion_queue* cq,
+                                             void* tag);
+
+/** Cancel all in-progress calls.
+    Only usable after shutdown. */
+GRPCAPI void grpc_server_cancel_all_calls(grpc_server* server);
+
+/** Destroy a server.
+    Shutdown must have completed beforehand (i.e. all tags generated by
+    grpc_server_shutdown_and_notify must have been received, and at least
+    one call to grpc_server_shutdown_and_notify must have been made). */
+GRPCAPI void grpc_server_destroy(grpc_server* server);
+
+/** Enable or disable a tracer.
+
+    Tracers (usually controlled by the environment variable GRPC_TRACE)
+    allow printf-style debugging on GRPC internals, and are useful for
+    tracking down problems in the field.
+
+    Use of this function is not strictly thread-safe, but the
+    thread-safety issues raised by it should not be of concern. */
+GRPCAPI int grpc_tracer_set_enabled(const char* name, int enabled);
+
+/** Check whether a metadata key is legal (will be accepted by core) */
+GRPCAPI int grpc_header_key_is_legal(grpc_slice slice);
+
+/** Check whether a non-binary metadata value is legal (will be accepted by
+    core) */
+GRPCAPI int grpc_header_nonbin_value_is_legal(grpc_slice slice);
+
+/** Check whether a metadata key corresponds to a binary value */
+GRPCAPI int grpc_is_binary_header(grpc_slice slice);
+
+/** Convert grpc_call_error values to a string */
+GRPCAPI const char* grpc_call_error_to_string(grpc_call_error error);
+
+/** Create a buffer pool */
+GRPCAPI grpc_resource_quota* grpc_resource_quota_create(const char* trace_name);
+
+/** Add a reference to a buffer pool */
+GRPCAPI void grpc_resource_quota_ref(grpc_resource_quota* resource_quota);
+
+/** Drop a reference to a buffer pool */
+GRPCAPI void grpc_resource_quota_unref(grpc_resource_quota* resource_quota);
+
+/** Update the size of a buffer pool */
+GRPCAPI void grpc_resource_quota_resize(grpc_resource_quota* resource_quota,
+                                        size_t new_size);
+
+/** Update the size of the maximum number of threads allowed */
+GRPCAPI void grpc_resource_quota_set_max_threads(
+    grpc_resource_quota* resource_quota, int new_max_threads);
+
+/** Fetch a vtable for a grpc_channel_arg that points to a grpc_resource_quota
+ */
+GRPCAPI const grpc_arg_pointer_vtable* grpc_resource_quota_arg_vtable(void);
+
+/************* CHANNELZ API *************/
+/** Channelz is under active development. The following APIs will see some
+    churn as the feature is implemented. This comment will be removed once
+    channelz is officially supported, and these APIs become stable. For now
+    you may track the progress by following this github issue:
+    https://github.com/grpc/grpc/issues/15340
+
+    the following APIs return allocated JSON strings that match the response
+    objects from the channelz proto, found here:
+    https://github.com/grpc/grpc/blob/master/src/proto/grpc/channelz/channelz.proto.
+
+    For easy conversion to protobuf, The JSON is formatted according to:
+    https://developers.google.com/protocol-buffers/docs/proto3#json. */
+
+/* Gets all root channels (i.e. channels the application has directly
+   created). This does not include subchannels nor non-top level channels.
+   The returned string is allocated and must be freed by the application. */
+GRPCAPI char* grpc_channelz_get_top_channels(intptr_t start_channel_id);
+
+/* Gets all servers that exist in the process. */
+GRPCAPI char* grpc_channelz_get_servers(intptr_t start_server_id);
+
+/* Returns a single Server, or else a NOT_FOUND code. */
+GRPCAPI char* grpc_channelz_get_server(intptr_t server_id);
+
+/* Gets all server sockets that exist in the server. */
+GRPCAPI char* grpc_channelz_get_server_sockets(intptr_t server_id,
+                                               intptr_t start_socket_id,
+                                               intptr_t max_results);
+
+/* Returns a single Channel, or else a NOT_FOUND code. The returned string
+   is allocated and must be freed by the application. */
+GRPCAPI char* grpc_channelz_get_channel(intptr_t channel_id);
+
+/* Returns a single Subchannel, or else a NOT_FOUND code. The returned string
+   is allocated and must be freed by the application. */
+GRPCAPI char* grpc_channelz_get_subchannel(intptr_t subchannel_id);
+
+/* Returns a single Socket, or else a NOT_FOUND code. The returned string
+   is allocated and must be freed by the application. */
+GRPCAPI char* grpc_channelz_get_socket(intptr_t socket_id);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_GRPC_H */
diff --git a/grpc/spm-core-include/grpc/grpc_cronet.h b/grpc/spm-core-include/grpc/grpc_cronet.h
new file mode 100644
index 00000000..289cfcda
--- /dev/null
+++ b/grpc/spm-core-include/grpc/grpc_cronet.h
@@ -0,0 +1,38 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_GRPC_CRONET_H
+#define GRPC_GRPC_CRONET_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/grpc.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+GRPCAPI grpc_channel* grpc_cronet_secure_channel_create(
+    void* engine, const char* target, const grpc_channel_args* args,
+    void* reserved);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_GRPC_CRONET_H */
diff --git a/grpc/spm-core-include/grpc/grpc_posix.h b/grpc/spm-core-include/grpc/grpc_posix.h
new file mode 100644
index 00000000..fbce5e13
--- /dev/null
+++ b/grpc/spm-core-include/grpc/grpc_posix.h
@@ -0,0 +1,59 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_GRPC_POSIX_H
+#define GRPC_GRPC_POSIX_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/grpc_types.h>
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*! \mainpage GRPC Core POSIX
+ *
+ * The GRPC Core POSIX library provides some POSIX-specific low-level
+ * functionality on top of GRPC Core.
+ */
+
+/** Create a client channel to 'target' using file descriptor 'fd'. The 'target'
+    argument will be used to indicate the name for this channel. See the comment
+    for grpc_insecure_channel_create for description of 'args' argument. */
+GRPCAPI grpc_channel* grpc_insecure_channel_create_from_fd(
+    const char* target, int fd, const grpc_channel_args* args);
+
+/** Add the connected communication channel based on file descriptor 'fd' to the
+    'server'. The 'fd' must be an open file descriptor corresponding to a
+    connected socket. Events from the file descriptor may come on any of the
+    server completion queues (i.e completion queues registered via the
+    grpc_server_register_completion_queue API).
+
+    The 'reserved' pointer MUST be NULL.
+    */
+GRPCAPI void grpc_server_add_insecure_channel_from_fd(grpc_server* server,
+                                                      void* reserved, int fd);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_GRPC_POSIX_H */
diff --git a/grpc/spm-core-include/grpc/grpc_security.h b/grpc/spm-core-include/grpc/grpc_security.h
new file mode 100644
index 00000000..c1d72955
--- /dev/null
+++ b/grpc/spm-core-include/grpc/grpc_security.h
@@ -0,0 +1,1087 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_GRPC_SECURITY_H
+#define GRPC_GRPC_SECURITY_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/grpc.h>
+#include <grpc/grpc_security_constants.h>
+#include <grpc/status.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** --- Authentication Context. --- */
+
+typedef struct grpc_auth_context grpc_auth_context;
+
+typedef struct grpc_auth_property_iterator {
+  const grpc_auth_context* ctx;
+  size_t index;
+  const char* name;
+} grpc_auth_property_iterator;
+
+/** value, if not NULL, is guaranteed to be NULL terminated. */
+typedef struct grpc_auth_property {
+  char* name;
+  char* value;
+  size_t value_length;
+} grpc_auth_property;
+
+/** Returns NULL when the iterator is at the end. */
+GRPCAPI const grpc_auth_property* grpc_auth_property_iterator_next(
+    grpc_auth_property_iterator* it);
+
+/** Iterates over the auth context. */
+GRPCAPI grpc_auth_property_iterator
+grpc_auth_context_property_iterator(const grpc_auth_context* ctx);
+
+/** Gets the peer identity. Returns an empty iterator (first _next will return
+   NULL) if the peer is not authenticated. */
+GRPCAPI grpc_auth_property_iterator
+grpc_auth_context_peer_identity(const grpc_auth_context* ctx);
+
+/** Finds a property in the context. May return an empty iterator (first _next
+   will return NULL) if no property with this name was found in the context. */
+GRPCAPI grpc_auth_property_iterator grpc_auth_context_find_properties_by_name(
+    const grpc_auth_context* ctx, const char* name);
+
+/** Gets the name of the property that indicates the peer identity. Will return
+   NULL if the peer is not authenticated. */
+GRPCAPI const char* grpc_auth_context_peer_identity_property_name(
+    const grpc_auth_context* ctx);
+
+/** Returns 1 if the peer is authenticated, 0 otherwise. */
+GRPCAPI int grpc_auth_context_peer_is_authenticated(
+    const grpc_auth_context* ctx);
+
+/** Gets the auth context from the call. Caller needs to call
+   grpc_auth_context_release on the returned context. */
+GRPCAPI grpc_auth_context* grpc_call_auth_context(grpc_call* call);
+
+/** Releases the auth context returned from grpc_call_auth_context. */
+GRPCAPI void grpc_auth_context_release(grpc_auth_context* context);
+
+/** --
+   The following auth context methods should only be called by a server metadata
+   processor to set properties extracted from auth metadata.
+   -- */
+
+/** Add a property. */
+GRPCAPI void grpc_auth_context_add_property(grpc_auth_context* ctx,
+                                            const char* name, const char* value,
+                                            size_t value_length);
+
+/** Add a C string property. */
+GRPCAPI void grpc_auth_context_add_cstring_property(grpc_auth_context* ctx,
+                                                    const char* name,
+                                                    const char* value);
+
+/** Sets the property name. Returns 1 if successful or 0 in case of failure
+   (which means that no property with this name exists). */
+GRPCAPI int grpc_auth_context_set_peer_identity_property_name(
+    grpc_auth_context* ctx, const char* name);
+
+/** --- SSL Session Cache. ---
+
+    A SSL session cache object represents a way to cache client sessions
+    between connections. Only ticket-based resumption is supported. */
+
+typedef struct grpc_ssl_session_cache grpc_ssl_session_cache;
+
+/** Create LRU cache for client-side SSL sessions with the given capacity.
+    If capacity is < 1, a default capacity is used instead. */
+GRPCAPI grpc_ssl_session_cache* grpc_ssl_session_cache_create_lru(
+    size_t capacity);
+
+/** Destroy SSL session cache. */
+GRPCAPI void grpc_ssl_session_cache_destroy(grpc_ssl_session_cache* cache);
+
+/** Create a channel arg with the given cache object. */
+GRPCAPI grpc_arg
+grpc_ssl_session_cache_create_channel_arg(grpc_ssl_session_cache* cache);
+
+/** --- grpc_call_credentials object.
+
+   A call credentials object represents a way to authenticate on a particular
+   call. These credentials can be composed with a channel credentials object
+   so that they are sent with every call on this channel.  */
+
+typedef struct grpc_call_credentials grpc_call_credentials;
+
+/** Releases a call credentials object.
+   The creator of the credentials object is responsible for its release. */
+GRPCAPI void grpc_call_credentials_release(grpc_call_credentials* creds);
+
+/** --- grpc_channel_credentials object. ---
+
+   A channel credentials object represents a way to authenticate a client on a
+   channel.  */
+
+typedef struct grpc_channel_credentials grpc_channel_credentials;
+
+/** Releases a channel credentials object.
+   The creator of the credentials object is responsible for its release. */
+GRPCAPI void grpc_channel_credentials_release(grpc_channel_credentials* creds);
+
+/** Creates default credentials to connect to a google gRPC service.
+   WARNING: Do NOT use this credentials to connect to a non-google service as
+   this could result in an oauth2 token leak. The security level of the
+   resulting connection is GRPC_PRIVACY_AND_INTEGRITY.
+
+   If specified, the supplied call credentials object will be attached to the
+   returned channel credentials object. The call_credentials object must remain
+   valid throughout the lifetime of the returned grpc_channel_credentials
+   object. It is expected that the call credentials object was generated
+   according to the Application Default Credentials mechanism and asserts the
+   identity of the default service account of the machine. Supplying any other
+   sort of call credential will result in undefined behavior, up to and
+   including the sudden and unexpected failure of RPCs.
+
+   If nullptr is supplied, the returned channel credentials object will use a
+   call credentials object based on the Application Default Credentials
+   mechanism.
+*/
+GRPCAPI grpc_channel_credentials* grpc_google_default_credentials_create(
+    grpc_call_credentials* call_credentials);
+
+/** Callback for getting the SSL roots override from the application.
+   In case of success, *pem_roots_certs must be set to a NULL terminated string
+   containing the list of PEM encoded root certificates. The ownership is passed
+   to the core and freed (laster by the core) with gpr_free.
+   If this function fails and GRPC_DEFAULT_SSL_ROOTS_FILE_PATH environment is
+   set to a valid path, it will override the roots specified this func */
+typedef grpc_ssl_roots_override_result (*grpc_ssl_roots_override_callback)(
+    char** pem_root_certs);
+
+/** Setup a callback to override the default TLS/SSL roots.
+   This function is not thread-safe and must be called at initialization time
+   before any ssl credentials are created to have the desired side effect.
+   If GRPC_DEFAULT_SSL_ROOTS_FILE_PATH environment is set to a valid path, the
+   callback will not be called. */
+GRPCAPI void grpc_set_ssl_roots_override_callback(
+    grpc_ssl_roots_override_callback cb);
+
+/** Object that holds a private key / certificate chain pair in PEM format. */
+typedef struct {
+  /** private_key is the NULL-terminated string containing the PEM encoding of
+     the client's private key. */
+  const char* private_key;
+
+  /** cert_chain is the NULL-terminated string containing the PEM encoding of
+     the client's certificate chain. */
+  const char* cert_chain;
+} grpc_ssl_pem_key_cert_pair;
+
+/** Deprecated in favor of grpc_ssl_verify_peer_options. It will be removed
+  after all of its call sites are migrated to grpc_ssl_verify_peer_options.
+  Object that holds additional peer-verification options on a secure
+  channel. */
+typedef struct {
+  /** If non-NULL this callback will be invoked with the expected
+     target_name, the peer's certificate (in PEM format), and whatever
+     userdata pointer is set below. If a non-zero value is returned by this
+     callback then it is treated as a verification failure. Invocation of
+     the callback is blocking, so any implementation should be light-weight.
+     */
+  int (*verify_peer_callback)(const char* target_name, const char* peer_pem,
+                              void* userdata);
+  /** Arbitrary userdata that will be passed as the last argument to
+     verify_peer_callback. */
+  void* verify_peer_callback_userdata;
+  /** A destruct callback that will be invoked when the channel is being
+     cleaned up. The userdata argument will be passed to it. The intent is
+     to perform any cleanup associated with that userdata. */
+  void (*verify_peer_destruct)(void* userdata);
+} verify_peer_options;
+
+/** Object that holds additional peer-verification options on a secure
+   channel. */
+typedef struct {
+  /** If non-NULL this callback will be invoked with the expected
+     target_name, the peer's certificate (in PEM format), and whatever
+     userdata pointer is set below. If a non-zero value is returned by this
+     callback then it is treated as a verification failure. Invocation of
+     the callback is blocking, so any implementation should be light-weight.
+     */
+  int (*verify_peer_callback)(const char* target_name, const char* peer_pem,
+                              void* userdata);
+  /** Arbitrary userdata that will be passed as the last argument to
+     verify_peer_callback. */
+  void* verify_peer_callback_userdata;
+  /** A destruct callback that will be invoked when the channel is being
+     cleaned up. The userdata argument will be passed to it. The intent is
+     to perform any cleanup associated with that userdata. */
+  void (*verify_peer_destruct)(void* userdata);
+} grpc_ssl_verify_peer_options;
+
+/** Deprecated in favor of grpc_ssl_server_credentials_create_ex. It will be
+   removed after all of its call sites are migrated to
+   grpc_ssl_server_credentials_create_ex. Creates an SSL credentials object.
+   The security level of the resulting connection is GRPC_PRIVACY_AND_INTEGRITY.
+   - pem_root_certs is the NULL-terminated string containing the PEM encoding
+     of the server root certificates. If this parameter is NULL, the
+     implementation will first try to dereference the file pointed by the
+     GRPC_DEFAULT_SSL_ROOTS_FILE_PATH environment variable, and if that fails,
+     try to get the roots set by grpc_override_ssl_default_roots. Eventually,
+     if all these fail, it will try to get the roots from a well-known place on
+     disk (in the grpc install directory).
+
+     gRPC has implemented root cache if the underlying OpenSSL library supports
+     it. The gRPC root certificates cache is only applicable on the default
+     root certificates, which is used when this parameter is nullptr. If user
+     provides their own pem_root_certs, when creating an SSL credential object,
+     gRPC would not be able to cache it, and each subchannel will generate a
+     copy of the root store. So it is recommended to avoid providing large room
+     pem with pem_root_certs parameter to avoid excessive memory consumption,
+     particularly on mobile platforms such as iOS.
+   - pem_key_cert_pair is a pointer on the object containing client's private
+     key and certificate chain. This parameter can be NULL if the client does
+     not have such a key/cert pair.
+   - verify_options is an optional verify_peer_options object which holds
+     additional options controlling how peer certificates are verified. For
+     example, you can supply a callback which receives the peer's certificate
+     with which you can do additional verification. Can be NULL, in which
+     case verification will retain default behavior. Any settings in
+     verify_options are copied during this call, so the verify_options
+     object can be released afterwards. */
+GRPCAPI grpc_channel_credentials* grpc_ssl_credentials_create(
+    const char* pem_root_certs, grpc_ssl_pem_key_cert_pair* pem_key_cert_pair,
+    const verify_peer_options* verify_options, void* reserved);
+
+/* Creates an SSL credentials object.
+   The security level of the resulting connection is GRPC_PRIVACY_AND_INTEGRITY.
+   - pem_root_certs is the NULL-terminated string containing the PEM encoding
+     of the server root certificates. If this parameter is NULL, the
+     implementation will first try to dereference the file pointed by the
+     GRPC_DEFAULT_SSL_ROOTS_FILE_PATH environment variable, and if that fails,
+     try to get the roots set by grpc_override_ssl_default_roots. Eventually,
+     if all these fail, it will try to get the roots from a well-known place on
+     disk (in the grpc install directory).
+
+     gRPC has implemented root cache if the underlying OpenSSL library supports
+     it. The gRPC root certificates cache is only applicable on the default
+     root certificates, which is used when this parameter is nullptr. If user
+     provides their own pem_root_certs, when creating an SSL credential object,
+     gRPC would not be able to cache it, and each subchannel will generate a
+     copy of the root store. So it is recommended to avoid providing large room
+     pem with pem_root_certs parameter to avoid excessive memory consumption,
+     particularly on mobile platforms such as iOS.
+   - pem_key_cert_pair is a pointer on the object containing client's private
+     key and certificate chain. This parameter can be NULL if the client does
+     not have such a key/cert pair.
+   - verify_options is an optional verify_peer_options object which holds
+     additional options controlling how peer certificates are verified. For
+     example, you can supply a callback which receives the peer's certificate
+     with which you can do additional verification. Can be NULL, in which
+     case verification will retain default behavior. Any settings in
+     verify_options are copied during this call, so the verify_options
+     object can be released afterwards. */
+GRPCAPI grpc_channel_credentials* grpc_ssl_credentials_create_ex(
+    const char* pem_root_certs, grpc_ssl_pem_key_cert_pair* pem_key_cert_pair,
+    const grpc_ssl_verify_peer_options* verify_options, void* reserved);
+
+/** Creates a composite channel credentials object. The security level of
+ * resulting connection is determined by channel_creds. */
+GRPCAPI grpc_channel_credentials* grpc_composite_channel_credentials_create(
+    grpc_channel_credentials* channel_creds, grpc_call_credentials* call_creds,
+    void* reserved);
+
+/** --- composite credentials. */
+
+/** Creates a composite call credentials object. */
+GRPCAPI grpc_call_credentials* grpc_composite_call_credentials_create(
+    grpc_call_credentials* creds1, grpc_call_credentials* creds2,
+    void* reserved);
+
+/** Creates a compute engine credentials object for connecting to Google.
+   WARNING: Do NOT use this credentials to connect to a non-google service as
+   this could result in an oauth2 token leak. */
+GRPCAPI grpc_call_credentials* grpc_google_compute_engine_credentials_create(
+    void* reserved);
+
+GRPCAPI gpr_timespec grpc_max_auth_token_lifetime(void);
+
+/** Creates a JWT credentials object. May return NULL if the input is invalid.
+   - json_key is the JSON key string containing the client's private key.
+   - token_lifetime is the lifetime of each Json Web Token (JWT) created with
+     this credentials.  It should not exceed grpc_max_auth_token_lifetime or
+     will be cropped to this value.  */
+GRPCAPI grpc_call_credentials*
+grpc_service_account_jwt_access_credentials_create(const char* json_key,
+                                                   gpr_timespec token_lifetime,
+                                                   void* reserved);
+
+/** Builds External Account credentials.
+ - json_string is the JSON string containing the credentials options.
+ - scopes_string contains the scopes to be binded with the credentials.
+   This API is used for experimental purposes for now and may change in the
+ future. */
+GRPCAPI grpc_call_credentials* grpc_external_account_credentials_create(
+    const char* json_string, const char* scopes_string);
+
+/** Creates an Oauth2 Refresh Token credentials object for connecting to Google.
+   May return NULL if the input is invalid.
+   WARNING: Do NOT use this credentials to connect to a non-google service as
+   this could result in an oauth2 token leak.
+   - json_refresh_token is the JSON string containing the refresh token itself
+     along with a client_id and client_secret. */
+GRPCAPI grpc_call_credentials* grpc_google_refresh_token_credentials_create(
+    const char* json_refresh_token, void* reserved);
+
+/** Creates an Oauth2 Access Token credentials with an access token that was
+   acquired by an out of band mechanism. */
+GRPCAPI grpc_call_credentials* grpc_access_token_credentials_create(
+    const char* access_token, void* reserved);
+
+/** Creates an IAM credentials object for connecting to Google. */
+GRPCAPI grpc_call_credentials* grpc_google_iam_credentials_create(
+    const char* authorization_token, const char* authority_selector,
+    void* reserved);
+
+/** Options for creating STS Oauth Token Exchange credentials following the IETF
+   draft https://tools.ietf.org/html/draft-ietf-oauth-token-exchange-16.
+   Optional fields may be set to NULL or empty string. It is the responsibility
+   of the caller to ensure that the subject and actor tokens are refreshed on
+   disk at the specified paths. This API is used for experimental purposes for
+   now and may change in the future. */
+typedef struct {
+  const char* token_exchange_service_uri; /* Required. */
+  const char* resource;                   /* Optional. */
+  const char* audience;                   /* Optional. */
+  const char* scope;                      /* Optional. */
+  const char* requested_token_type;       /* Optional. */
+  const char* subject_token_path;         /* Required. */
+  const char* subject_token_type;         /* Required. */
+  const char* actor_token_path;           /* Optional. */
+  const char* actor_token_type;           /* Optional. */
+} grpc_sts_credentials_options;
+
+/** Creates an STS credentials following the STS Token Exchanged specifed in the
+   IETF draft https://tools.ietf.org/html/draft-ietf-oauth-token-exchange-16.
+   This API is used for experimental purposes for now and may change in the
+   future. */
+GRPCAPI grpc_call_credentials* grpc_sts_credentials_create(
+    const grpc_sts_credentials_options* options, void* reserved);
+
+/** Callback function to be called by the metadata credentials plugin
+   implementation when the metadata is ready.
+   - user_data is the opaque pointer that was passed in the get_metadata method
+     of the grpc_metadata_credentials_plugin (see below).
+   - creds_md is an array of credentials metadata produced by the plugin. It
+     may be set to NULL in case of an error.
+   - num_creds_md is the number of items in the creds_md array.
+   - status must be GRPC_STATUS_OK in case of success or another specific error
+     code otherwise.
+   - error_details contains details about the error if any. In case of success
+     it should be NULL and will be otherwise ignored. */
+typedef void (*grpc_credentials_plugin_metadata_cb)(
+    void* user_data, const grpc_metadata* creds_md, size_t num_creds_md,
+    grpc_status_code status, const char* error_details);
+
+/** Context that can be used by metadata credentials plugin in order to create
+   auth related metadata. */
+typedef struct {
+  /** The fully qualifed service url. */
+  const char* service_url;
+
+  /** The method name of the RPC being called (not fully qualified).
+     The fully qualified method name can be built from the service_url:
+     full_qualified_method_name = ctx->service_url + '/' + ctx->method_name. */
+  const char* method_name;
+
+  /** The auth_context of the channel which gives the server's identity. */
+  const grpc_auth_context* channel_auth_context;
+
+  /** Reserved for future use. */
+  void* reserved;
+} grpc_auth_metadata_context;
+
+/** Performs a deep copy from \a from to \a to. **/
+GRPCAPI void grpc_auth_metadata_context_copy(grpc_auth_metadata_context* from,
+                                             grpc_auth_metadata_context* to);
+
+/** Releases internal resources held by \a context. **/
+GRPCAPI void grpc_auth_metadata_context_reset(
+    grpc_auth_metadata_context* context);
+
+/** Maximum number of metadata entries returnable by a credentials plugin via
+    a synchronous return. */
+#define GRPC_METADATA_CREDENTIALS_PLUGIN_SYNC_MAX 4
+
+/** grpc_metadata_credentials plugin is an API user provided structure used to
+   create grpc_credentials objects that can be set on a channel (composed) or
+   a call. See grpc_credentials_metadata_create_from_plugin below.
+   The grpc client stack will call the get_metadata method of the plugin for
+   every call in scope for the credentials created from it. */
+typedef struct {
+  /** The implementation of this method has to be non-blocking, but can
+     be performed synchronously or asynchronously.
+
+     If processing occurs synchronously, returns non-zero and populates
+     creds_md, num_creds_md, status, and error_details.  In this case,
+     the caller takes ownership of the entries in creds_md and of
+     error_details.  Note that if the plugin needs to return more than
+     GRPC_METADATA_CREDENTIALS_PLUGIN_SYNC_MAX entries in creds_md, it must
+     return asynchronously.
+
+     If processing occurs asynchronously, returns zero and invokes \a cb
+     when processing is completed.  \a user_data will be passed as the
+     first parameter of the callback.  NOTE: \a cb MUST be invoked in a
+     different thread, not from the thread in which \a get_metadata() is
+     invoked.
+
+     \a context is the information that can be used by the plugin to create
+     auth metadata. */
+  int (*get_metadata)(
+      void* state, grpc_auth_metadata_context context,
+      grpc_credentials_plugin_metadata_cb cb, void* user_data,
+      grpc_metadata creds_md[GRPC_METADATA_CREDENTIALS_PLUGIN_SYNC_MAX],
+      size_t* num_creds_md, grpc_status_code* status,
+      const char** error_details);
+
+  /** Implements debug string of the given plugin. This method returns an
+   * allocated string that the caller needs to free using gpr_free() */
+  char* (*debug_string)(void* state);
+
+  /** Destroys the plugin state. */
+  void (*destroy)(void* state);
+
+  /** State that will be set as the first parameter of the methods above. */
+  void* state;
+
+  /** Type of credentials that this plugin is implementing. */
+  const char* type;
+} grpc_metadata_credentials_plugin;
+
+/** Creates a credentials object from a plugin with a specified minimum security
+ * level. */
+GRPCAPI grpc_call_credentials* grpc_metadata_credentials_create_from_plugin(
+    grpc_metadata_credentials_plugin plugin,
+    grpc_security_level min_security_level, void* reserved);
+
+/** --- Secure channel creation. --- */
+
+/** Creates a secure channel using the passed-in credentials. Additional
+    channel level configuration MAY be provided by grpc_channel_args, though
+    the expectation is that most clients will want to simply pass NULL. The
+    user data in 'args' need only live through the invocation of this function.
+    However, if any args of the 'pointer' type are passed, then the referenced
+    vtable must be maintained by the caller until grpc_channel_destroy
+    terminates. See grpc_channel_args definition for more on this. */
+GRPCAPI grpc_channel* grpc_secure_channel_create(
+    grpc_channel_credentials* creds, const char* target,
+    const grpc_channel_args* args, void* reserved);
+
+/** --- grpc_server_credentials object. ---
+
+   A server credentials object represents a way to authenticate a server.  */
+
+typedef struct grpc_server_credentials grpc_server_credentials;
+
+/** Releases a server_credentials object.
+   The creator of the server_credentials object is responsible for its release.
+   */
+GRPCAPI void grpc_server_credentials_release(grpc_server_credentials* creds);
+
+/** Server certificate config object holds the server's public certificates and
+   associated private keys, as well as any CA certificates needed for client
+   certificate validation (if applicable). Create using
+   grpc_ssl_server_certificate_config_create(). */
+typedef struct grpc_ssl_server_certificate_config
+    grpc_ssl_server_certificate_config;
+
+/** Creates a grpc_ssl_server_certificate_config object.
+   - pem_roots_cert is the NULL-terminated string containing the PEM encoding of
+     the client root certificates. This parameter may be NULL if the server does
+     not want the client to be authenticated with SSL.
+   - pem_key_cert_pairs is an array private key / certificate chains of the
+     server. This parameter cannot be NULL.
+   - num_key_cert_pairs indicates the number of items in the private_key_files
+     and cert_chain_files parameters. It must be at least 1.
+   - It is the caller's responsibility to free this object via
+     grpc_ssl_server_certificate_config_destroy(). */
+GRPCAPI grpc_ssl_server_certificate_config*
+grpc_ssl_server_certificate_config_create(
+    const char* pem_root_certs,
+    const grpc_ssl_pem_key_cert_pair* pem_key_cert_pairs,
+    size_t num_key_cert_pairs);
+
+/** Destroys a grpc_ssl_server_certificate_config object. */
+GRPCAPI void grpc_ssl_server_certificate_config_destroy(
+    grpc_ssl_server_certificate_config* config);
+
+/** Callback to retrieve updated SSL server certificates, private keys, and
+   trusted CAs (for client authentication).
+    - user_data parameter, if not NULL, contains opaque data to be used by the
+      callback.
+    - Use grpc_ssl_server_certificate_config_create to create the config.
+    - The caller assumes ownership of the config. */
+typedef grpc_ssl_certificate_config_reload_status (
+    *grpc_ssl_server_certificate_config_callback)(
+    void* user_data, grpc_ssl_server_certificate_config** config);
+
+/** Deprecated in favor of grpc_ssl_server_credentials_create_ex.
+   Creates an SSL server_credentials object.
+   - pem_roots_cert is the NULL-terminated string containing the PEM encoding of
+     the client root certificates. This parameter may be NULL if the server does
+     not want the client to be authenticated with SSL.
+   - pem_key_cert_pairs is an array private key / certificate chains of the
+     server. This parameter cannot be NULL.
+   - num_key_cert_pairs indicates the number of items in the private_key_files
+     and cert_chain_files parameters. It should be at least 1.
+   - force_client_auth, if set to non-zero will force the client to authenticate
+     with an SSL cert. Note that this option is ignored if pem_root_certs is
+     NULL. */
+GRPCAPI grpc_server_credentials* grpc_ssl_server_credentials_create(
+    const char* pem_root_certs, grpc_ssl_pem_key_cert_pair* pem_key_cert_pairs,
+    size_t num_key_cert_pairs, int force_client_auth, void* reserved);
+
+/** Deprecated in favor of grpc_ssl_server_credentials_create_with_options.
+   Same as grpc_ssl_server_credentials_create method except uses
+   grpc_ssl_client_certificate_request_type enum to support more ways to
+   authenticate client certificates.*/
+GRPCAPI grpc_server_credentials* grpc_ssl_server_credentials_create_ex(
+    const char* pem_root_certs, grpc_ssl_pem_key_cert_pair* pem_key_cert_pairs,
+    size_t num_key_cert_pairs,
+    grpc_ssl_client_certificate_request_type client_certificate_request,
+    void* reserved);
+
+typedef struct grpc_ssl_server_credentials_options
+    grpc_ssl_server_credentials_options;
+
+/** Creates an options object using a certificate config. Use this method when
+   the certificates and keys of the SSL server will not change during the
+   server's lifetime.
+   - Takes ownership of the certificate_config parameter. */
+GRPCAPI grpc_ssl_server_credentials_options*
+grpc_ssl_server_credentials_create_options_using_config(
+    grpc_ssl_client_certificate_request_type client_certificate_request,
+    grpc_ssl_server_certificate_config* certificate_config);
+
+/** Creates an options object using a certificate config fetcher. Use this
+   method to reload the certificates and keys of the SSL server without
+   interrupting the operation of the server. Initial certificate config will be
+   fetched during server initialization.
+   - user_data parameter, if not NULL, contains opaque data which will be passed
+     to the fetcher (see definition of
+     grpc_ssl_server_certificate_config_callback). */
+GRPCAPI grpc_ssl_server_credentials_options*
+grpc_ssl_server_credentials_create_options_using_config_fetcher(
+    grpc_ssl_client_certificate_request_type client_certificate_request,
+    grpc_ssl_server_certificate_config_callback cb, void* user_data);
+
+/** Destroys a grpc_ssl_server_credentials_options object. */
+GRPCAPI void grpc_ssl_server_credentials_options_destroy(
+    grpc_ssl_server_credentials_options* options);
+
+/** Creates an SSL server_credentials object using the provided options struct.
+    - Takes ownership of the options parameter. */
+GRPCAPI grpc_server_credentials*
+grpc_ssl_server_credentials_create_with_options(
+    grpc_ssl_server_credentials_options* options);
+
+/** --- Server-side secure ports. --- */
+
+/** Add a HTTP2 over an encrypted link over tcp listener.
+   Returns bound port number on success, 0 on failure.
+   REQUIRES: server not started */
+GRPCAPI int grpc_server_add_secure_http2_port(grpc_server* server,
+                                              const char* addr,
+                                              grpc_server_credentials* creds);
+
+/** --- Call specific credentials. --- */
+
+/** Sets a credentials to a call. Can only be called on the client side before
+   grpc_call_start_batch. */
+GRPCAPI grpc_call_error grpc_call_set_credentials(grpc_call* call,
+                                                  grpc_call_credentials* creds);
+
+/** --- Auth Metadata Processing --- */
+
+/** Callback function that is called when the metadata processing is done.
+   - Consumed metadata will be removed from the set of metadata available on the
+     call. consumed_md may be NULL if no metadata has been consumed.
+   - Response metadata will be set on the response. response_md may be NULL.
+   - status is GRPC_STATUS_OK for success or a specific status for an error.
+     Common error status for auth metadata processing is either
+     GRPC_STATUS_UNAUTHENTICATED in case of an authentication failure or
+     GRPC_STATUS PERMISSION_DENIED in case of an authorization failure.
+   - error_details gives details about the error. May be NULL. */
+typedef void (*grpc_process_auth_metadata_done_cb)(
+    void* user_data, const grpc_metadata* consumed_md, size_t num_consumed_md,
+    const grpc_metadata* response_md, size_t num_response_md,
+    grpc_status_code status, const char* error_details);
+
+/** Pluggable server-side metadata processor object. */
+typedef struct {
+  /** The context object is read/write: it contains the properties of the
+     channel peer and it is the job of the process function to augment it with
+     properties derived from the passed-in metadata.
+     The lifetime of these objects is guaranteed until cb is invoked. */
+  void (*process)(void* state, grpc_auth_context* context,
+                  const grpc_metadata* md, size_t num_md,
+                  grpc_process_auth_metadata_done_cb cb, void* user_data);
+  void (*destroy)(void* state);
+  void* state;
+} grpc_auth_metadata_processor;
+
+GRPCAPI void grpc_server_credentials_set_auth_metadata_processor(
+    grpc_server_credentials* creds, grpc_auth_metadata_processor processor);
+
+/** --- ALTS channel/server credentials --- **/
+
+/**
+ * Main interface for ALTS credentials options. The options will contain
+ * information that will be passed from grpc to TSI layer such as RPC protocol
+ * versions. ALTS client (channel) and server credentials will have their own
+ * implementation of this interface. The APIs listed in this header are
+ * thread-compatible. It is used for experimental purpose for now and subject
+ * to change.
+ */
+typedef struct grpc_alts_credentials_options grpc_alts_credentials_options;
+
+/**
+ * This method creates a grpc ALTS credentials client options instance.
+ * It is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI grpc_alts_credentials_options*
+grpc_alts_credentials_client_options_create(void);
+
+/**
+ * This method creates a grpc ALTS credentials server options instance.
+ * It is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI grpc_alts_credentials_options*
+grpc_alts_credentials_server_options_create(void);
+
+/**
+ * This method adds a target service account to grpc client's ALTS credentials
+ * options instance. It is used for experimental purpose for now and subject
+ * to change.
+ *
+ * - options: grpc ALTS credentials options instance.
+ * - service_account: service account of target endpoint.
+ */
+GRPCAPI void grpc_alts_credentials_client_options_add_target_service_account(
+    grpc_alts_credentials_options* options, const char* service_account);
+
+/**
+ * This method destroys a grpc_alts_credentials_options instance by
+ * de-allocating all of its occupied memory. It is used for experimental purpose
+ * for now and subject to change.
+ *
+ * - options: a grpc_alts_credentials_options instance that needs to be
+ *   destroyed.
+ */
+GRPCAPI void grpc_alts_credentials_options_destroy(
+    grpc_alts_credentials_options* options);
+
+/**
+ * This method creates an ALTS channel credential object. The security
+ * level of the resulting connection is GRPC_PRIVACY_AND_INTEGRITY.
+ * It is used for experimental purpose for now and subject to change.
+ *
+ * - options: grpc ALTS credentials options instance for client.
+ *
+ * It returns the created ALTS channel credential object.
+ */
+GRPCAPI grpc_channel_credentials* grpc_alts_credentials_create(
+    const grpc_alts_credentials_options* options);
+
+/**
+ * This method creates an ALTS server credential object. It is used for
+ * experimental purpose for now and subject to change.
+ *
+ * - options: grpc ALTS credentials options instance for server.
+ *
+ * It returns the created ALTS server credential object.
+ */
+GRPCAPI grpc_server_credentials* grpc_alts_server_credentials_create(
+    const grpc_alts_credentials_options* options);
+
+/** --- Local channel/server credentials --- **/
+
+/**
+ * This method creates a local channel credential object. The security level
+ * of the resulting connection is GRPC_PRIVACY_AND_INTEGRITY for UDS and
+ * GRPC_SECURITY_NONE for LOCAL_TCP. It is used for experimental purpose
+ * for now and subject to change.
+ *
+ * - type: local connection type
+ *
+ * It returns the created local channel credential object.
+ */
+GRPCAPI grpc_channel_credentials* grpc_local_credentials_create(
+    grpc_local_connect_type type);
+
+/**
+ * This method creates a local server credential object. It is used for
+ * experimental purpose for now and subject to change.
+ *
+ * - type: local connection type
+ *
+ * It returns the created local server credential object.
+ */
+GRPCAPI grpc_server_credentials* grpc_local_server_credentials_create(
+    grpc_local_connect_type type);
+
+/** --- TLS channel/server credentials ---
+ * It is used for experimental purpose for now and subject to change. */
+
+/** Struct for indicating errors. It is used for
+ *  experimental purpose for now and subject to change. */
+typedef struct grpc_tls_error_details grpc_tls_error_details;
+
+/** Config for TLS server authorization check. It is used for
+ *  experimental purpose for now and subject to change. */
+typedef struct grpc_tls_server_authorization_check_config
+    grpc_tls_server_authorization_check_config;
+
+/**
+ * A struct that can be specified by callers to configure underlying TLS
+ * behaviors. It is used for experimental purpose for now and subject to change.
+ */
+typedef struct grpc_tls_credentials_options grpc_tls_credentials_options;
+
+/**
+ * A struct provides ways to gain credential data that will be used in the TLS
+ * handshake. It is used for experimental purpose for now and subject to change.
+ */
+typedef struct grpc_tls_certificate_provider grpc_tls_certificate_provider;
+
+/**
+ * A struct that stores the credential data presented to the peer in handshake
+ * to show local identity. It is used for experimental purpose for now and
+ * subject to change.
+ */
+typedef struct grpc_tls_identity_pairs grpc_tls_identity_pairs;
+
+/**
+ * Creates a grpc_tls_identity_pairs that stores a list of identity credential
+ * data, including identity private key and identity certificate chain. It is
+ * used for experimental purpose for now and subject to change.
+ */
+GRPCAPI grpc_tls_identity_pairs* grpc_tls_identity_pairs_create();
+
+/**
+ * Adds a identity private key and a identity certificate chain to
+ * grpc_tls_identity_pairs. This function will make an internal copy of
+ * |private_key| and |cert_chain|. It is used for experimental purpose for now
+ * and subject to change.
+ */
+GRPCAPI void grpc_tls_identity_pairs_add_pair(grpc_tls_identity_pairs* pairs,
+                                              const char* private_key,
+                                              const char* cert_chain);
+
+/**
+ * Destroys a grpc_tls_identity_pairs object. If this object is passed to a
+ * provider initiation function, the ownership is transferred so this function
+ * doesn't need to be called. Otherwise the creator of the
+ * grpc_tls_identity_pairs object is responsible for its destruction. It is
+ * used for experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_identity_pairs_destroy(grpc_tls_identity_pairs* pairs);
+
+/**
+ * Creates a grpc_tls_certificate_provider that will load credential data from
+ * static string during initialization. This provider will always return the
+ * same cert data for all cert names.
+ * root_certificate and pem_key_cert_pairs can be nullptr, indicating the
+ * corresponding credential data is not needed.
+ * This function will make a copy of |root_certificate|.
+ * The ownership of |pem_key_cert_pairs| is transferred.
+ * It is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI grpc_tls_certificate_provider*
+grpc_tls_certificate_provider_static_data_create(
+    const char* root_certificate, grpc_tls_identity_pairs* pem_key_cert_pairs);
+
+/**
+ * Creates a grpc_tls_certificate_provider that will watch the credential
+ * changes on the file system. This provider will always return the up-to-date
+ * cert data for all the cert names callers set through
+ * |grpc_tls_credentials_options|. Note that this API only supports one key-cert
+ * file and hence one set of identity key-cert pair, so SNI(Server Name
+ * Indication) is not supported.
+ * - private_key_path is the file path of the private key. This must be set if
+ *   |identity_certificate_path| is set. Otherwise, it could be null if no
+ *   identity credentials are needed.
+ * - identity_certificate_path is the file path of the identity certificate
+ *   chain. This must be set if |private_key_path| is set. Otherwise, it could
+ *   be null if no identity credentials are needed.
+ * - root_cert_path is the file path to the root certificate bundle. This
+ *   may be null if no root certs are needed.
+ * - refresh_interval_sec is the refreshing interval that we will check the
+ *   files for updates.
+ * It does not take ownership of parameters.
+ * It is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI grpc_tls_certificate_provider*
+grpc_tls_certificate_provider_file_watcher_create(
+    const char* private_key_path, const char* identity_certificate_path,
+    const char* root_cert_path, unsigned int refresh_interval_sec);
+
+/**
+ * Releases a grpc_tls_certificate_provider object. The creator of the
+ * grpc_tls_certificate_provider object is responsible for its release. It is
+ * used for experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_certificate_provider_release(
+    grpc_tls_certificate_provider* provider);
+
+/**
+ * Creates an grpc_tls_credentials_options.
+ * It is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI grpc_tls_credentials_options* grpc_tls_credentials_options_create(void);
+
+/**
+ * Sets the options of whether to request and verify client certs. This should
+ * be called only on the server side. It returns 1 on success and 0 on failure.
+ * It is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_credentials_options_set_cert_request_type(
+    grpc_tls_credentials_options* options,
+    grpc_ssl_client_certificate_request_type type);
+
+/**
+ * Sets the options of whether to choose certain checks, e.g. certificate check,
+ * hostname check, etc. This should be called only on the client side. If
+ * |server_verification_option| is not GRPC_TLS_SERVER_VERIFICATION, use of a
+ * custom authorization check (grpc_tls_server_authorization_check_config) is
+ * mandatory. It returns 1 on success and 0 on failure. It is used for
+ * experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_credentials_options_set_server_verification_option(
+    grpc_tls_credentials_options* options,
+    grpc_tls_server_verification_option server_verification_option);
+
+/**
+ * Sets the credential provider in the options.
+ * The |options| will implicitly take a new ref to the |provider|.
+ * It returns 1 on success and 0 on failure.
+ * It is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_credentials_options_set_certificate_provider(
+    grpc_tls_credentials_options* options,
+    grpc_tls_certificate_provider* provider);
+
+/**
+ * If set, gRPC stack will keep watching the root certificates with
+ * name |root_cert_name|. It returns 1 on success and 0 on failure. It is used
+ * for experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_credentials_options_watch_root_certs(
+    grpc_tls_credentials_options* options);
+
+/**
+ * Sets the name of the root certificates being watched.
+ * If not set, We will use a default empty string as the root certificate name.
+ * It is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_credentials_options_set_root_cert_name(
+    grpc_tls_credentials_options* options, const char* root_cert_name);
+
+/**
+ * If set, gRPC stack will keep watching the identity key-cert pairs
+ * with name |identity_cert_name|. It returns 1 on success and 0 on failure. It
+ * is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_credentials_options_watch_identity_key_cert_pairs(
+    grpc_tls_credentials_options* options);
+
+/**
+ * Sets the name of the identity certificates being watched.
+ * If not set, We will use a default empty string as the identity certificate
+ * name. It is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_credentials_options_set_identity_cert_name(
+    grpc_tls_credentials_options* options, const char* identity_cert_name);
+
+/**
+ * Sets the configuration for a custom authorization check performed at the end
+ * of the handshake. The |options| will implicitly take a new ref to the
+ * |config|. It returns 1 on success and 0 on failure. It is used for
+ * experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_credentials_options_set_server_authorization_check_config(
+    grpc_tls_credentials_options* options,
+    grpc_tls_server_authorization_check_config* config);
+
+/** --- TLS server authorization check config. ---
+ *  It is used for experimental purpose for now and subject to change. */
+
+typedef struct grpc_tls_server_authorization_check_arg
+    grpc_tls_server_authorization_check_arg;
+
+/** callback function provided by gRPC used to handle the result of server
+    authorization check. It is used when schedule API is implemented
+    asynchronously, and serves to bring the control back to gRPC C core. It is
+    used for experimental purpose for now and subject to change. */
+typedef void (*grpc_tls_on_server_authorization_check_done_cb)(
+    grpc_tls_server_authorization_check_arg* arg);
+
+/** A struct containing all information necessary to schedule/cancel a server
+    authorization check request.
+    - cb and cb_user_data represent a gRPC-provided callback and an argument
+      passed to it.
+    - success will store the result of server authorization check. That is,
+      if success returns a non-zero value, it means the authorization check
+      passes and if returning zero, it means the check fails.
+   - target_name is the name of an endpoint the channel is connecting to.
+   - peer_cert represents a complete certificate chain including both
+     signing and leaf certificates.
+   - \a subject_alternative_names is an array of size
+     \a subject_alternative_names_size consisting of pointers to strings.
+   - status and error_details contain information
+     about errors occurred when a server authorization check request is
+     scheduled/cancelled.
+   - config is a pointer to the unique
+     grpc_tls_server_authorization_check_config instance that this argument
+     corresponds to.
+   - context is a pointer to a wrapped language implementation of this
+     grpc_tls_server_authorization_check_arg instance.
+   - destroy_context is a pointer to a caller-provided method that cleans
+      up any data associated with the context pointer.
+   It is used for experimental purpose for now and subject to change.
+*/
+struct grpc_tls_server_authorization_check_arg {
+  grpc_tls_on_server_authorization_check_done_cb cb;
+  void* cb_user_data;
+  int success;
+  const char* target_name;
+  const char* peer_cert;
+  const char* peer_cert_full_chain;
+  char** subject_alternative_names;
+  size_t subject_alternative_names_size;
+  grpc_status_code status;
+  grpc_tls_error_details* error_details;
+  grpc_tls_server_authorization_check_config* config;
+  void* context;
+  void (*destroy_context)(void* ctx);
+};
+
+/** Create a grpc_tls_server_authorization_check_config instance.
+    - config_user_data is config-specific, read-only user data
+      that works for all channels created with a credential using the config.
+    - schedule is a pointer to an application-provided callback used to invoke
+      server authorization check API. The implementation of this method has to
+      be non-blocking, but can be performed synchronously or asynchronously.
+      1)If processing occurs synchronously, it populates arg->result,
+      arg->status, and arg->error_details and returns zero.
+      2) If processing occurs asynchronously, it returns a non-zero value. The
+      application then invokes arg->cb when processing is completed. Note that
+      arg->cb cannot be invoked before schedule API returns.
+    - cancel is a pointer to an application-provided callback used to cancel a
+      server authorization check request scheduled via an asynchronous schedule
+      API. arg is used to pinpoint an exact check request to be cancelled. The
+      operation may not have any effect if the request has already been
+      processed.
+    - destruct is a pointer to an application-provided callback used to clean up
+      any data associated with the config.
+    It is used for experimental purpose for now and subject to change.
+*/
+GRPCAPI grpc_tls_server_authorization_check_config*
+grpc_tls_server_authorization_check_config_create(
+    const void* config_user_data,
+    int (*schedule)(void* config_user_data,
+                    grpc_tls_server_authorization_check_arg* arg),
+    void (*cancel)(void* config_user_data,
+                   grpc_tls_server_authorization_check_arg* arg),
+    void (*destruct)(void* config_user_data));
+
+/**
+ * Releases a grpc_tls_server_authorization_check_config object. The creator of
+ * the grpc_tls_server_authorization_check_config object is responsible for its
+ * release. It is used for experimental purpose for now and subject to change.
+ */
+GRPCAPI void grpc_tls_server_authorization_check_config_release(
+    grpc_tls_server_authorization_check_config* config);
+
+/**
+ * Creates a TLS channel credential object based on the
+ * grpc_tls_credentials_options specified by callers. The
+ * grpc_channel_credentials will take the ownership of the |options|. The
+ * security level of the resulting connection is GRPC_PRIVACY_AND_INTEGRITY. It
+ * is used for experimental purpose for now and subject to change.
+ */
+grpc_channel_credentials* grpc_tls_credentials_create(
+    grpc_tls_credentials_options* options);
+
+/**
+ * Creates a TLS server credential object based on the
+ * grpc_tls_credentials_options specified by callers. The
+ * grpc_server_credentials will take the ownership of the |options|. It
+ * is used for experimental purpose for now and subject to change.
+ */
+grpc_server_credentials* grpc_tls_server_credentials_create(
+    grpc_tls_credentials_options* options);
+
+/**
+ * EXPERIMENTAL API - Subject to change
+ *
+ * This method creates an insecure channel credentials object.
+ */
+grpc_channel_credentials* grpc_insecure_credentials_create();
+
+/**
+ * EXPERIMENTAL API - Subject to change
+ *
+ * This method creates an insecure server credentials object.
+ */
+grpc_server_credentials* grpc_insecure_server_credentials_create();
+
+/**
+ * EXPERIMENTAL API - Subject to change
+ *
+ * This method creates an xDS channel credentials object.
+ *
+ * Creating a channel with credentials of this type indicates that the channel
+ * should get credentials configuration from the xDS control plane.
+ *
+ * \a fallback_credentials are used if the channel target does not have the
+ * 'xds:///' scheme or if the xDS control plane does not provide information on
+ * how to fetch credentials dynamically. Does NOT take ownership of the \a
+ * fallback_credentials. (Internally takes a ref to the object.)
+ */
+GRPCAPI grpc_channel_credentials* grpc_xds_credentials_create(
+    grpc_channel_credentials* fallback_credentials);
+
+/**
+ * EXPERIMENTAL API - Subject to change
+ *
+ * This method creates an xDS server credentials object.
+ *
+ * \a fallback_credentials are used if the xDS control plane does not provide
+ * information on how to fetch credentials dynamically.
+ *
+ * Does NOT take ownership of the \a fallback_credentials. (Internally takes
+ * a ref to the object.)
+ */
+GRPCAPI grpc_server_credentials* grpc_xds_server_credentials_create(
+    grpc_server_credentials* fallback_credentials);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_GRPC_SECURITY_H */
diff --git a/grpc/spm-core-include/grpc/grpc_security_constants.h b/grpc/spm-core-include/grpc/grpc_security_constants.h
new file mode 100644
index 00000000..a62f7675
--- /dev/null
+++ b/grpc/spm-core-include/grpc/grpc_security_constants.h
@@ -0,0 +1,149 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_GRPC_SECURITY_CONSTANTS_H
+#define GRPC_GRPC_SECURITY_CONSTANTS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define GRPC_TRANSPORT_SECURITY_TYPE_PROPERTY_NAME "transport_security_type"
+#define GRPC_SSL_TRANSPORT_SECURITY_TYPE "ssl"
+
+#define GRPC_X509_CN_PROPERTY_NAME "x509_common_name"
+#define GRPC_X509_SAN_PROPERTY_NAME "x509_subject_alternative_name"
+#define GRPC_X509_PEM_CERT_PROPERTY_NAME "x509_pem_cert"
+#define GRPC_X509_PEM_CERT_CHAIN_PROPERTY_NAME "x509_pem_cert_chain"
+#define GRPC_SSL_SESSION_REUSED_PROPERTY "ssl_session_reused"
+#define GRPC_TRANSPORT_SECURITY_LEVEL_PROPERTY_NAME "security_level"
+#define GRPC_PEER_SPIFFE_ID_PROPERTY_NAME "peer_spiffe_id"
+
+/** Environment variable that points to the default SSL roots file. This file
+   must be a PEM encoded file with all the roots such as the one that can be
+   downloaded from https://pki.google.com/roots.pem.  */
+#define GRPC_DEFAULT_SSL_ROOTS_FILE_PATH_ENV_VAR \
+  "GRPC_DEFAULT_SSL_ROOTS_FILE_PATH"
+
+/** Environment variable that points to the google default application
+   credentials json key or refresh token. Used in the
+   grpc_google_default_credentials_create function. */
+#define GRPC_GOOGLE_CREDENTIALS_ENV_VAR "GOOGLE_APPLICATION_CREDENTIALS"
+
+/** Results for the SSL roots override callback. */
+typedef enum {
+  GRPC_SSL_ROOTS_OVERRIDE_OK,
+  GRPC_SSL_ROOTS_OVERRIDE_FAIL_PERMANENTLY, /** Do not try fallback options. */
+  GRPC_SSL_ROOTS_OVERRIDE_FAIL
+} grpc_ssl_roots_override_result;
+
+/** Callback results for dynamically loading a SSL certificate config. */
+typedef enum {
+  GRPC_SSL_CERTIFICATE_CONFIG_RELOAD_UNCHANGED,
+  GRPC_SSL_CERTIFICATE_CONFIG_RELOAD_NEW,
+  GRPC_SSL_CERTIFICATE_CONFIG_RELOAD_FAIL
+} grpc_ssl_certificate_config_reload_status;
+
+typedef enum {
+  /** Server does not request client certificate.
+     The certificate presented by the client is not checked by the server at
+     all. (A client may present a self signed or signed certificate or not
+     present a certificate at all and any of those option would be accepted) */
+  GRPC_SSL_DONT_REQUEST_CLIENT_CERTIFICATE,
+  /** Server requests client certificate but does not enforce that the client
+     presents a certificate.
+
+     If the client presents a certificate, the client authentication is left to
+     the application (the necessary metadata will be available to the
+     application via authentication context properties, see grpc_auth_context).
+
+     The client's key certificate pair must be valid for the SSL connection to
+     be established. */
+  GRPC_SSL_REQUEST_CLIENT_CERTIFICATE_BUT_DONT_VERIFY,
+  /** Server requests client certificate but does not enforce that the client
+     presents a certificate.
+
+     If the client presents a certificate, the client authentication is done by
+     the gRPC framework. (For a successful connection the client needs to either
+     present a certificate that can be verified against the root certificate
+     configured by the server or not present a certificate at all)
+
+     The client's key certificate pair must be valid for the SSL connection to
+     be established. */
+  GRPC_SSL_REQUEST_CLIENT_CERTIFICATE_AND_VERIFY,
+  /** Server requests client certificate and enforces that the client presents a
+     certificate.
+
+     If the client presents a certificate, the client authentication is left to
+     the application (the necessary metadata will be available to the
+     application via authentication context properties, see grpc_auth_context).
+
+     The client's key certificate pair must be valid for the SSL connection to
+     be established. */
+  GRPC_SSL_REQUEST_AND_REQUIRE_CLIENT_CERTIFICATE_BUT_DONT_VERIFY,
+  /** Server requests client certificate and enforces that the client presents a
+     certificate.
+
+     The certificate presented by the client is verified by the gRPC framework.
+     (For a successful connection the client needs to present a certificate that
+     can be verified against the root certificate configured by the server)
+
+     The client's key certificate pair must be valid for the SSL connection to
+     be established. */
+  GRPC_SSL_REQUEST_AND_REQUIRE_CLIENT_CERTIFICATE_AND_VERIFY
+} grpc_ssl_client_certificate_request_type;
+
+/* Security levels of grpc transport security. It represents an inherent
+ * property of a backend connection and is determined by a channel credential
+ * used to create the connection. */
+typedef enum {
+  GRPC_SECURITY_MIN,
+  GRPC_SECURITY_NONE = GRPC_SECURITY_MIN,
+  GRPC_INTEGRITY_ONLY,
+  GRPC_PRIVACY_AND_INTEGRITY,
+  GRPC_SECURITY_MAX = GRPC_PRIVACY_AND_INTEGRITY,
+} grpc_security_level;
+
+typedef enum {
+  /** Default option: performs server certificate verification and hostname
+     verification. */
+  GRPC_TLS_SERVER_VERIFICATION,
+  /** Performs server certificate verification, but skips hostname verification
+     Client is responsible for verifying server's identity via
+     server authorization check callback. */
+  GRPC_TLS_SKIP_HOSTNAME_VERIFICATION,
+  /** Skips both server certificate and hostname verification.
+     Client is responsible for verifying server's identity and
+     server's certificate via server authorization check callback. */
+  GRPC_TLS_SKIP_ALL_SERVER_VERIFICATION
+} grpc_tls_server_verification_option;
+
+/**
+ * Type of local connections for which local channel/server credentials will be
+ * applied. It supports UDS and local TCP connections.
+ */
+typedef enum { UDS = 0, LOCAL_TCP } grpc_local_connect_type;
+
+/** The TLS versions that are supported by the SSL stack. **/
+typedef enum { TLS1_2, TLS1_3 } grpc_tls_version;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_GRPC_SECURITY_CONSTANTS_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/README.md b/grpc/spm-core-include/grpc/impl/codegen/README.md
new file mode 100644
index 00000000..1bafd001
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/README.md
@@ -0,0 +1,22 @@
+# Welcome to `include/grpc/impl/codegen`
+
+## Why is this directory here?
+
+This directory exists so that generated C++ code can include selected files upon
+which it depends without having to depend on the entire gRPC C++ library. This
+directory thus exists to support `include/grpcpp/impl/codegen`. This constraint
+is particularly relevant for users of bazel, particularly if they use the
+multi-lingual `proto_library` target type. Generated code that uses this target
+only depends on the gRPC C++ targets associated with these header files, not the
+entire gRPC C++ codebase since that would make the build time of these types of
+targets excessively large (particularly when they are not even C++ specific).
+
+## What should user code do?
+
+User code should *not* include anything from this directory. Only generated code
+and gRPC library code should include contents from this directory. C++ user code
+should instead include contents from the main `grpcpp` directory or its
+accessible subcomponents like `grpcpp/support`. It is possible that we may
+remove this directory altogether if the motivations for its existence are no
+longer strong enough (e.g., if the gRPC C++ library no longer has a need for an
+`impl/codegen` directory of its own).
diff --git a/grpc/spm-core-include/grpc/impl/codegen/atm.h b/grpc/spm-core-include/grpc/impl/codegen/atm.h
new file mode 100644
index 00000000..00d83f06
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/atm.h
@@ -0,0 +1,95 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_ATM_H
+#define GRPC_IMPL_CODEGEN_ATM_H
+
+/** This interface provides atomic operations and barriers.
+   It is internal to gpr support code and should not be used outside it.
+
+   If an operation with acquire semantics precedes another memory access by the
+   same thread, the operation will precede that other access as seen by other
+   threads.
+
+   If an operation with release semantics follows another memory access by the
+   same thread, the operation will follow that other access as seen by other
+   threads.
+
+   Routines with "acq" or "full" in the name have acquire semantics.  Routines
+   with "rel" or "full" in the name have release semantics.  Routines with
+   "no_barrier" in the name have neither acquire not release semantics.
+
+   The routines may be implemented as macros.
+
+   // Atomic operations act on an intergral_type gpr_atm that is guaranteed to
+   // be the same size as a pointer.
+   typedef intptr_t gpr_atm;
+
+   // A memory barrier, providing both acquire and release semantics, but not
+   // otherwise acting on memory.
+   void gpr_atm_full_barrier(void);
+
+   // Atomically return *p, with acquire semantics.
+   gpr_atm gpr_atm_acq_load(gpr_atm *p);
+   gpr_atm gpr_atm_no_barrier_load(gpr_atm *p);
+
+   // Atomically set *p = value, with release semantics.
+   void gpr_atm_rel_store(gpr_atm *p, gpr_atm value);
+
+   // Atomically add delta to *p, and return the old value of *p, with
+   // the barriers specified.
+   gpr_atm gpr_atm_no_barrier_fetch_add(gpr_atm *p, gpr_atm delta);
+   gpr_atm gpr_atm_full_fetch_add(gpr_atm *p, gpr_atm delta);
+
+   // Atomically, if *p==o, set *p=n and return non-zero otherwise return 0,
+   // with the barriers specified if the operation succeeds.
+   int gpr_atm_no_barrier_cas(gpr_atm *p, gpr_atm o, gpr_atm n);
+   int gpr_atm_acq_cas(gpr_atm *p, gpr_atm o, gpr_atm n);
+   int gpr_atm_rel_cas(gpr_atm *p, gpr_atm o, gpr_atm n);
+   int gpr_atm_full_cas(gpr_atm *p, gpr_atm o, gpr_atm n);
+
+   // Atomically, set *p=n and return the old value of *p
+   gpr_atm gpr_atm_full_xchg(gpr_atm *p, gpr_atm n);
+*/
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#if defined(GPR_GCC_ATOMIC)
+#include <grpc/impl/codegen/atm_gcc_atomic.h>
+#elif defined(GPR_GCC_SYNC)
+#include <grpc/impl/codegen/atm_gcc_sync.h>
+#elif defined(GPR_WINDOWS_ATOMIC)
+#include <grpc/impl/codegen/atm_windows.h>
+#else
+#error could not determine platform for atm
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Adds \a delta to \a *value, clamping the result to the range specified
+    by \a min and \a max.  Returns the new value. */
+gpr_atm gpr_atm_no_barrier_clamped_add(gpr_atm* value, gpr_atm delta,
+                                       gpr_atm min, gpr_atm max);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_ATM_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/atm_gcc_atomic.h b/grpc/spm-core-include/grpc/impl/codegen/atm_gcc_atomic.h
new file mode 100644
index 00000000..58797085
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/atm_gcc_atomic.h
@@ -0,0 +1,91 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_ATM_GCC_ATOMIC_H
+#define GRPC_IMPL_CODEGEN_ATM_GCC_ATOMIC_H
+
+/* atm_platform.h for gcc and gcc-like compilers with the
+   __atomic_* interface.  */
+#include <grpc/impl/codegen/port_platform.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef intptr_t gpr_atm;
+#define GPR_ATM_MAX INTPTR_MAX
+#define GPR_ATM_MIN INTPTR_MIN
+
+#ifdef GPR_LOW_LEVEL_COUNTERS
+extern gpr_atm gpr_counter_atm_cas;
+extern gpr_atm gpr_counter_atm_add;
+#define GPR_ATM_INC_COUNTER(counter) \
+  __atomic_fetch_add(&counter, 1, __ATOMIC_RELAXED)
+#define GPR_ATM_INC_CAS_THEN(blah) \
+  (GPR_ATM_INC_COUNTER(gpr_counter_atm_cas), blah)
+#define GPR_ATM_INC_ADD_THEN(blah) \
+  (GPR_ATM_INC_COUNTER(gpr_counter_atm_add), blah)
+#else
+#define GPR_ATM_INC_CAS_THEN(blah) blah
+#define GPR_ATM_INC_ADD_THEN(blah) blah
+#endif
+
+#define gpr_atm_full_barrier() (__atomic_thread_fence(__ATOMIC_SEQ_CST))
+
+#define gpr_atm_acq_load(p) (__atomic_load_n((p), __ATOMIC_ACQUIRE))
+#define gpr_atm_no_barrier_load(p) (__atomic_load_n((p), __ATOMIC_RELAXED))
+#define gpr_atm_rel_store(p, value) \
+  (__atomic_store_n((p), (intptr_t)(value), __ATOMIC_RELEASE))
+#define gpr_atm_no_barrier_store(p, value) \
+  (__atomic_store_n((p), (intptr_t)(value), __ATOMIC_RELAXED))
+
+#define gpr_atm_no_barrier_fetch_add(p, delta) \
+  GPR_ATM_INC_ADD_THEN(                        \
+      __atomic_fetch_add((p), (intptr_t)(delta), __ATOMIC_RELAXED))
+#define gpr_atm_full_fetch_add(p, delta) \
+  GPR_ATM_INC_ADD_THEN(                  \
+      __atomic_fetch_add((p), (intptr_t)(delta), __ATOMIC_ACQ_REL))
+
+static __inline int gpr_atm_no_barrier_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
+  return GPR_ATM_INC_CAS_THEN(__atomic_compare_exchange_n(
+      p, &o, n, 0, __ATOMIC_RELAXED, __ATOMIC_RELAXED));
+}
+
+static __inline int gpr_atm_acq_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
+  return GPR_ATM_INC_CAS_THEN(__atomic_compare_exchange_n(
+      p, &o, n, 0, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED));
+}
+
+static __inline int gpr_atm_rel_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
+  return GPR_ATM_INC_CAS_THEN(__atomic_compare_exchange_n(
+      p, &o, n, 0, __ATOMIC_RELEASE, __ATOMIC_RELAXED));
+}
+
+static __inline int gpr_atm_full_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
+  return GPR_ATM_INC_CAS_THEN(__atomic_compare_exchange_n(
+      p, &o, n, 0, __ATOMIC_ACQ_REL, __ATOMIC_RELAXED));
+}
+
+#define gpr_atm_full_xchg(p, n) \
+  GPR_ATM_INC_CAS_THEN(__atomic_exchange_n((p), (n), __ATOMIC_ACQ_REL))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_ATM_GCC_ATOMIC_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/atm_gcc_sync.h b/grpc/spm-core-include/grpc/impl/codegen/atm_gcc_sync.h
new file mode 100644
index 00000000..728c3d54
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/atm_gcc_sync.h
@@ -0,0 +1,85 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_ATM_GCC_SYNC_H
+#define GRPC_IMPL_CODEGEN_ATM_GCC_SYNC_H
+
+/* variant of atm_platform.h for gcc and gcc-like compiers with __sync_*
+   interface */
+#include <grpc/impl/codegen/port_platform.h>
+
+typedef intptr_t gpr_atm;
+#define GPR_ATM_MAX INTPTR_MAX
+#define GPR_ATM_MIN INTPTR_MIN
+#define GPR_ATM_INC_CAS_THEN(blah) blah
+#define GPR_ATM_INC_ADD_THEN(blah) blah
+
+#define GPR_ATM_COMPILE_BARRIER_() __asm__ __volatile__("" : : : "memory")
+
+#if defined(__i386) || defined(__x86_64__)
+/* All loads are acquire loads and all stores are release stores.  */
+#define GPR_ATM_LS_BARRIER_() GPR_ATM_COMPILE_BARRIER_()
+#else
+#define GPR_ATM_LS_BARRIER_() gpr_atm_full_barrier()
+#endif
+
+#define gpr_atm_full_barrier() (__sync_synchronize())
+
+static __inline gpr_atm gpr_atm_acq_load(const gpr_atm* p) {
+  gpr_atm value = *p;
+  GPR_ATM_LS_BARRIER_();
+  return value;
+}
+
+static __inline gpr_atm gpr_atm_no_barrier_load(const gpr_atm* p) {
+  gpr_atm value = *p;
+  GPR_ATM_COMPILE_BARRIER_();
+  return value;
+}
+
+static __inline void gpr_atm_rel_store(gpr_atm* p, gpr_atm value) {
+  GPR_ATM_LS_BARRIER_();
+  *p = value;
+}
+
+static __inline void gpr_atm_no_barrier_store(gpr_atm* p, gpr_atm value) {
+  GPR_ATM_COMPILE_BARRIER_();
+  *p = value;
+}
+
+#undef GPR_ATM_LS_BARRIER_
+#undef GPR_ATM_COMPILE_BARRIER_
+
+#define gpr_atm_no_barrier_fetch_add(p, delta) \
+  gpr_atm_full_fetch_add((p), (delta))
+#define gpr_atm_full_fetch_add(p, delta) (__sync_fetch_and_add((p), (delta)))
+
+#define gpr_atm_no_barrier_cas(p, o, n) gpr_atm_acq_cas((p), (o), (n))
+#define gpr_atm_acq_cas(p, o, n) (__sync_bool_compare_and_swap((p), (o), (n)))
+#define gpr_atm_rel_cas(p, o, n) gpr_atm_acq_cas((p), (o), (n))
+#define gpr_atm_full_cas(p, o, n) gpr_atm_acq_cas((p), (o), (n))
+
+static __inline gpr_atm gpr_atm_full_xchg(gpr_atm* p, gpr_atm n) {
+  gpr_atm cur;
+  do {
+    cur = gpr_atm_acq_load(p);
+  } while (!gpr_atm_rel_cas(p, cur, n));
+  return cur;
+}
+
+#endif /* GRPC_IMPL_CODEGEN_ATM_GCC_SYNC_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/atm_windows.h b/grpc/spm-core-include/grpc/impl/codegen/atm_windows.h
new file mode 100644
index 00000000..36c76ab6
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/atm_windows.h
@@ -0,0 +1,132 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_ATM_WINDOWS_H
+#define GRPC_IMPL_CODEGEN_ATM_WINDOWS_H
+
+/** Win32 variant of atm_platform.h */
+#include <grpc/impl/codegen/port_platform.h>
+
+#ifdef GPR_WINDOWS
+
+typedef intptr_t gpr_atm;
+#define GPR_ATM_MAX INTPTR_MAX
+#define GPR_ATM_MIN INTPTR_MIN
+#define GPR_ATM_INC_CAS_THEN(blah) blah
+#define GPR_ATM_INC_ADD_THEN(blah) blah
+
+#define gpr_atm_full_barrier MemoryBarrier
+
+static __inline gpr_atm gpr_atm_acq_load(const gpr_atm* p) {
+  gpr_atm result = *p;
+  gpr_atm_full_barrier();
+  return result;
+}
+
+static __inline gpr_atm gpr_atm_no_barrier_load(const gpr_atm* p) {
+  /* TODO(dklempner): Can we implement something better here? */
+  return gpr_atm_acq_load(p);
+}
+
+static __inline void gpr_atm_rel_store(gpr_atm* p, gpr_atm value) {
+  gpr_atm_full_barrier();
+  *p = value;
+}
+
+static __inline void gpr_atm_no_barrier_store(gpr_atm* p, gpr_atm value) {
+  /* TODO(ctiller): Can we implement something better here? */
+  gpr_atm_rel_store(p, value);
+}
+
+static __inline int gpr_atm_no_barrier_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
+/** InterlockedCompareExchangePointerNoFence() not available on vista or
+   windows7 */
+#ifdef GPR_ARCH_64
+  return o == (gpr_atm)InterlockedCompareExchangeAcquire64(
+                  (volatile LONGLONG*)p, (LONGLONG)n, (LONGLONG)o);
+#else
+  return o == (gpr_atm)InterlockedCompareExchangeAcquire((volatile LONG*)p,
+                                                         (LONG)n, (LONG)o);
+#endif
+}
+
+static __inline int gpr_atm_acq_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
+#ifdef GPR_ARCH_64
+  return o == (gpr_atm)InterlockedCompareExchangeAcquire64(
+                  (volatile LONGLONG*)p, (LONGLONG)n, (LONGLONG)o);
+#else
+  return o == (gpr_atm)InterlockedCompareExchangeAcquire((volatile LONG*)p,
+                                                         (LONG)n, (LONG)o);
+#endif
+}
+
+static __inline int gpr_atm_rel_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
+#ifdef GPR_ARCH_64
+  return o == (gpr_atm)InterlockedCompareExchangeRelease64(
+                  (volatile LONGLONG*)p, (LONGLONG)n, (LONGLONG)o);
+#else
+  return o == (gpr_atm)InterlockedCompareExchangeRelease((volatile LONG*)p,
+                                                         (LONG)n, (LONG)o);
+#endif
+}
+
+static __inline int gpr_atm_full_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
+#ifdef GPR_ARCH_64
+  return o == (gpr_atm)InterlockedCompareExchange64((volatile LONGLONG*)p,
+                                                    (LONGLONG)n, (LONGLONG)o);
+#else
+  return o == (gpr_atm)InterlockedCompareExchange((volatile LONG*)p, (LONG)n,
+                                                  (LONG)o);
+#endif
+}
+
+static __inline gpr_atm gpr_atm_no_barrier_fetch_add(gpr_atm* p,
+                                                     gpr_atm delta) {
+  /** Use the CAS operation to get pointer-sized fetch and add */
+  gpr_atm old;
+  do {
+    old = *p;
+  } while (!gpr_atm_no_barrier_cas(p, old, old + delta));
+  return old;
+}
+
+static __inline gpr_atm gpr_atm_full_fetch_add(gpr_atm* p, gpr_atm delta) {
+  /** Use a CAS operation to get pointer-sized fetch and add */
+  gpr_atm old;
+#ifdef GPR_ARCH_64
+  do {
+    old = *p;
+  } while (old != (gpr_atm)InterlockedCompareExchange64((volatile LONGLONG*)p,
+                                                        (LONGLONG)old + delta,
+                                                        (LONGLONG)old));
+#else
+  do {
+    old = *p;
+  } while (old != (gpr_atm)InterlockedCompareExchange(
+                      (volatile LONG*)p, (LONG)old + delta, (LONG)old));
+#endif
+  return old;
+}
+
+static __inline gpr_atm gpr_atm_full_xchg(gpr_atm* p, gpr_atm n) {
+  return (gpr_atm)InterlockedExchangePointer((PVOID*)p, (PVOID)n);
+}
+
+#endif /* GPR_WINDOWS */
+
+#endif /* GRPC_IMPL_CODEGEN_ATM_WINDOWS_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/byte_buffer.h b/grpc/spm-core-include/grpc/impl/codegen/byte_buffer.h
new file mode 100644
index 00000000..04137292
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/byte_buffer.h
@@ -0,0 +1,101 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_BYTE_BUFFER_H
+#define GRPC_IMPL_CODEGEN_BYTE_BUFFER_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <grpc/impl/codegen/grpc_types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Returns a RAW byte buffer instance over the given slices (up to \a nslices).
+ *
+ * Increases the reference count for all \a slices processed. The user is
+ * responsible for invoking grpc_byte_buffer_destroy on the returned instance.*/
+GRPCAPI grpc_byte_buffer* grpc_raw_byte_buffer_create(grpc_slice* slices,
+                                                      size_t nslices);
+
+/** Returns a *compressed* RAW byte buffer instance over the given slices (up to
+ * \a nslices). The \a compression argument defines the compression algorithm
+ * used to generate the data in \a slices.
+ *
+ * Increases the reference count for all \a slices processed. The user is
+ * responsible for invoking grpc_byte_buffer_destroy on the returned instance.*/
+GRPCAPI grpc_byte_buffer* grpc_raw_compressed_byte_buffer_create(
+    grpc_slice* slices, size_t nslices, grpc_compression_algorithm compression);
+
+/** Copies input byte buffer \a bb.
+ *
+ * Increases the reference count of all the source slices. The user is
+ * responsible for calling grpc_byte_buffer_destroy over the returned copy. */
+GRPCAPI grpc_byte_buffer* grpc_byte_buffer_copy(grpc_byte_buffer* bb);
+
+/** Returns the size of the given byte buffer, in bytes. */
+GRPCAPI size_t grpc_byte_buffer_length(grpc_byte_buffer* bb);
+
+/** Destroys \a byte_buffer deallocating all its memory. */
+GRPCAPI void grpc_byte_buffer_destroy(grpc_byte_buffer* bb);
+
+/** Reader for byte buffers. Iterates over slices in the byte buffer */
+struct grpc_byte_buffer_reader;
+typedef struct grpc_byte_buffer_reader grpc_byte_buffer_reader;
+
+/** Initialize \a reader to read over \a buffer.
+ * Returns 1 upon success, 0 otherwise. */
+GRPCAPI int grpc_byte_buffer_reader_init(grpc_byte_buffer_reader* reader,
+                                         grpc_byte_buffer* buffer);
+
+/** Cleanup and destroy \a reader */
+GRPCAPI void grpc_byte_buffer_reader_destroy(grpc_byte_buffer_reader* reader);
+
+/** Updates \a slice with the next piece of data from from \a reader and returns
+ * 1. Returns 0 at the end of the stream. Caller is responsible for calling
+ * grpc_slice_unref on the result. */
+GRPCAPI int grpc_byte_buffer_reader_next(grpc_byte_buffer_reader* reader,
+                                         grpc_slice* slice);
+
+/** EXPERIMENTAL API - This function may be removed and changed, in the future.
+ *
+ * Updates \a slice with the next piece of data from from \a reader and returns
+ * 1. Returns 0 at the end of the stream. Caller is responsible for making sure
+ * the slice pointer remains valid when accessed.
+ *
+ * NOTE: Do not use this function unless the caller can guarantee that the
+ *       underlying grpc_byte_buffer outlasts the use of the slice. This is only
+ *       safe when the underlying grpc_byte_buffer remains immutable while slice
+ *       is being accessed. */
+GRPCAPI int grpc_byte_buffer_reader_peek(grpc_byte_buffer_reader* reader,
+                                         grpc_slice** slice);
+
+/** Merge all data from \a reader into single slice */
+GRPCAPI grpc_slice
+grpc_byte_buffer_reader_readall(grpc_byte_buffer_reader* reader);
+
+/** Returns a RAW byte buffer instance from the output of \a reader. */
+GRPCAPI grpc_byte_buffer* grpc_raw_byte_buffer_from_reader(
+    grpc_byte_buffer_reader* reader);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_BYTE_BUFFER_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/byte_buffer_reader.h b/grpc/spm-core-include/grpc/impl/codegen/byte_buffer_reader.h
new file mode 100644
index 00000000..e06e1955
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/byte_buffer_reader.h
@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_BYTE_BUFFER_READER_H
+#define GRPC_IMPL_CODEGEN_BYTE_BUFFER_READER_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct grpc_byte_buffer;
+
+struct grpc_byte_buffer_reader {
+  struct grpc_byte_buffer* buffer_in;
+  struct grpc_byte_buffer* buffer_out;
+  /** Different current objects correspond to different types of byte buffers */
+  union grpc_byte_buffer_reader_current {
+    /** Index into a slice buffer's array of slices */
+    unsigned index;
+  } current;
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_BYTE_BUFFER_READER_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/compression_types.h b/grpc/spm-core-include/grpc/impl/codegen/compression_types.h
new file mode 100644
index 00000000..f778b005
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/compression_types.h
@@ -0,0 +1,108 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_COMPRESSION_TYPES_H
+#define GRPC_IMPL_CODEGEN_COMPRESSION_TYPES_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** To be used as initial metadata key for the request of a concrete compression
+ * algorithm */
+#define GRPC_COMPRESSION_REQUEST_ALGORITHM_MD_KEY \
+  "grpc-internal-encoding-request"
+
+/** To be used in channel arguments.
+ *
+ * \addtogroup grpc_arg_keys
+ * \{ */
+/** Default compression algorithm for the channel.
+ * Its value is an int from the \a grpc_compression_algorithm enum. */
+#define GRPC_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM \
+  "grpc.default_compression_algorithm"
+/** Default compression level for the channel.
+ * Its value is an int from the \a grpc_compression_level enum. */
+#define GRPC_COMPRESSION_CHANNEL_DEFAULT_LEVEL "grpc.default_compression_level"
+/** Compression algorithms supported by the channel.
+ * Its value is a bitset (an int). Bits correspond to algorithms in \a
+ * grpc_compression_algorithm. For example, its LSB corresponds to
+ * GRPC_COMPRESS_NONE, the next bit to GRPC_COMPRESS_DEFLATE, etc.
+ * Unset bits disable support for the algorithm. By default all algorithms are
+ * supported. It's not possible to disable GRPC_COMPRESS_NONE (the attempt will
+ * be ignored). */
+#define GRPC_COMPRESSION_CHANNEL_ENABLED_ALGORITHMS_BITSET \
+  "grpc.compression_enabled_algorithms_bitset"
+/** \} */
+
+/** The various compression algorithms supported by gRPC (not sorted by
+ * compression level) */
+typedef enum {
+  GRPC_COMPRESS_NONE = 0,
+  GRPC_COMPRESS_DEFLATE,
+  GRPC_COMPRESS_GZIP,
+  /* EXPERIMENTAL: Stream compression is currently experimental. */
+  GRPC_COMPRESS_STREAM_GZIP,
+  /* TODO(ctiller): snappy */
+  GRPC_COMPRESS_ALGORITHMS_COUNT
+} grpc_compression_algorithm;
+
+/** Compression levels allow a party with knowledge of its peer's accepted
+ * encodings to request compression in an abstract way. The level-algorithm
+ * mapping is performed internally and depends on the peer's supported
+ * compression algorithms. */
+typedef enum {
+  GRPC_COMPRESS_LEVEL_NONE = 0,
+  GRPC_COMPRESS_LEVEL_LOW,
+  GRPC_COMPRESS_LEVEL_MED,
+  GRPC_COMPRESS_LEVEL_HIGH,
+  GRPC_COMPRESS_LEVEL_COUNT
+} grpc_compression_level;
+
+typedef struct grpc_compression_options {
+  /** All algs are enabled by default. This option corresponds to the channel
+   * argument key behind \a GRPC_COMPRESSION_CHANNEL_ENABLED_ALGORITHMS_BITSET
+   */
+  uint32_t enabled_algorithms_bitset;
+
+  /** The default compression level. It'll be used in the absence of call
+   * specific settings. This option corresponds to the channel
+   * argument key behind \a GRPC_COMPRESSION_CHANNEL_DEFAULT_LEVEL. If present,
+   * takes precedence over \a default_algorithm.
+   * TODO(dgq): currently only available for server channels. */
+  struct grpc_compression_options_default_level {
+    int is_set;
+    grpc_compression_level level;
+  } default_level;
+
+  /** The default message compression algorithm. It'll be used in the absence of
+   * call specific settings. This option corresponds to the channel argument key
+   * behind \a GRPC_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM. */
+  struct grpc_compression_options_default_algorithm {
+    int is_set;
+    grpc_compression_algorithm algorithm;
+  } default_algorithm;
+} grpc_compression_options;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_COMPRESSION_TYPES_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/connectivity_state.h b/grpc/spm-core-include/grpc/impl/codegen/connectivity_state.h
new file mode 100644
index 00000000..b70dbef3
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/connectivity_state.h
@@ -0,0 +1,44 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_CONNECTIVITY_STATE_H
+#define GRPC_IMPL_CODEGEN_CONNECTIVITY_STATE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Connectivity state of a channel. */
+typedef enum {
+  /** channel is idle */
+  GRPC_CHANNEL_IDLE,
+  /** channel is connecting */
+  GRPC_CHANNEL_CONNECTING,
+  /** channel is ready for work */
+  GRPC_CHANNEL_READY,
+  /** channel has seen a failure but expects to recover */
+  GRPC_CHANNEL_TRANSIENT_FAILURE,
+  /** channel has seen a failure that it cannot recover from */
+  GRPC_CHANNEL_SHUTDOWN
+} grpc_connectivity_state;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_CONNECTIVITY_STATE_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/fork.h b/grpc/spm-core-include/grpc/impl/codegen/fork.h
new file mode 100644
index 00000000..555df349
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/fork.h
@@ -0,0 +1,48 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_FORK_H
+#define GRPC_IMPL_CODEGEN_FORK_H
+
+/**
+ * gRPC applications should call this before calling fork().  There should be no
+ * active gRPC function calls between calling grpc_prefork() and
+ * grpc_postfork_parent()/grpc_postfork_child().
+ *
+ *
+ * Typical use:
+ * grpc_prefork();
+ * int pid = fork();
+ * if (pid) {
+ *  grpc_postfork_parent();
+ *  // Parent process..
+ * } else {
+ *  grpc_postfork_child();
+ *  // Child process...
+ * }
+ */
+
+void grpc_prefork(void);
+
+void grpc_postfork_parent(void);
+
+void grpc_postfork_child(void);
+
+void grpc_fork_handlers_auto_register(void);
+
+#endif /* GRPC_IMPL_CODEGEN_FORK_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/gpr_slice.h b/grpc/spm-core-include/grpc/impl/codegen/gpr_slice.h
new file mode 100644
index 00000000..89fa72d5
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/gpr_slice.h
@@ -0,0 +1,69 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+#ifndef GRPC_IMPL_CODEGEN_GPR_SLICE_H
+#define GRPC_IMPL_CODEGEN_GPR_SLICE_H
+
+/** WARNING: Please do not use this header. This was added as a temporary
+ * measure to not break some of the external projects that depend on
+ * gpr_slice_* functions. We are actively working on moving all the
+ * gpr_slice_* references to grpc_slice_* and this file will be removed
+ */
+
+/* TODO (sreek) - Allowed by default but will be very soon turned off */
+#define GRPC_ALLOW_GPR_SLICE_FUNCTIONS 1
+
+#ifdef GRPC_ALLOW_GPR_SLICE_FUNCTIONS
+
+#define gpr_slice_refcount grpc_slice_refcount
+#define gpr_slice grpc_slice
+#define gpr_slice_buffer grpc_slice_buffer
+
+#define gpr_slice_ref grpc_slice_ref
+#define gpr_slice_unref grpc_slice_unref
+#define gpr_slice_new grpc_slice_new
+#define gpr_slice_new_with_user_data grpc_slice_new_with_user_data
+#define gpr_slice_new_with_len grpc_slice_new_with_len
+#define gpr_slice_malloc grpc_slice_malloc
+#define gpr_slice_from_copied_string grpc_slice_from_copied_string
+#define gpr_slice_from_copied_buffer grpc_slice_from_copied_buffer
+#define gpr_slice_from_static_string grpc_slice_from_static_string
+#define gpr_slice_sub grpc_slice_sub
+#define gpr_slice_sub_no_ref grpc_slice_sub_no_ref
+#define gpr_slice_split_tail grpc_slice_split_tail
+#define gpr_slice_split_head grpc_slice_split_head
+#define gpr_slice_cmp grpc_slice_cmp
+#define gpr_slice_str_cmp grpc_slice_str_cmp
+
+#define gpr_slice_buffer grpc_slice_buffer
+#define gpr_slice_buffer_init grpc_slice_buffer_init
+#define gpr_slice_buffer_destroy grpc_slice_buffer_destroy
+#define gpr_slice_buffer_add grpc_slice_buffer_add
+#define gpr_slice_buffer_add_indexed grpc_slice_buffer_add_indexed
+#define gpr_slice_buffer_addn grpc_slice_buffer_addn
+#define gpr_slice_buffer_tiny_add grpc_slice_buffer_tiny_add
+#define gpr_slice_buffer_pop grpc_slice_buffer_pop
+#define gpr_slice_buffer_reset_and_unref grpc_slice_buffer_reset_and_unref
+#define gpr_slice_buffer_swap grpc_slice_buffer_swap
+#define gpr_slice_buffer_move_into grpc_slice_buffer_move_into
+#define gpr_slice_buffer_trim_end grpc_slice_buffer_trim_end
+#define gpr_slice_buffer_move_first grpc_slice_buffer_move_first
+#define gpr_slice_buffer_take_first grpc_slice_buffer_take_first
+
+#endif /* GRPC_ALLOW_GPR_SLICE_FUNCTIONS */
+
+#endif /* GRPC_IMPL_CODEGEN_GPR_SLICE_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/gpr_types.h b/grpc/spm-core-include/grpc/impl/codegen/gpr_types.h
new file mode 100644
index 00000000..6daf3398
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/gpr_types.h
@@ -0,0 +1,59 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_GPR_TYPES_H
+#define GRPC_IMPL_CODEGEN_GPR_TYPES_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** The clocks we support. */
+typedef enum {
+  /** Monotonic clock. Epoch undefined. Always moves forwards. */
+  GPR_CLOCK_MONOTONIC = 0,
+  /** Realtime clock. May jump forwards or backwards. Settable by
+     the system administrator. Has its epoch at 0:00:00 UTC 1 Jan 1970. */
+  GPR_CLOCK_REALTIME,
+  /** CPU cycle time obtained by rdtsc instruction on x86 platforms. Epoch
+     undefined. Degrades to GPR_CLOCK_REALTIME on other platforms. */
+  GPR_CLOCK_PRECISE,
+  /** Unmeasurable clock type: no base, created by taking the difference
+     between two times */
+  GPR_TIMESPAN
+} gpr_clock_type;
+
+/** Analogous to struct timespec. On some machines, absolute times may be in
+ * local time. */
+typedef struct gpr_timespec {
+  int64_t tv_sec;
+  int32_t tv_nsec;
+  /** Against which clock was this time measured? (or GPR_TIMESPAN if
+      this is a relative time measure) */
+  gpr_clock_type clock_type;
+} gpr_timespec;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_GPR_TYPES_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/grpc_types.h b/grpc/spm-core-include/grpc/impl/codegen/grpc_types.h
new file mode 100644
index 00000000..d67a9e97
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/grpc_types.h
@@ -0,0 +1,789 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_GRPC_TYPES_H
+#define GRPC_IMPL_CODEGEN_GRPC_TYPES_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <grpc/impl/codegen/compression_types.h>
+#include <grpc/impl/codegen/gpr_types.h>
+#include <grpc/impl/codegen/slice.h>
+#include <grpc/impl/codegen/status.h>
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum {
+  GRPC_BB_RAW
+  /** Future types may include GRPC_BB_PROTOBUF, etc. */
+} grpc_byte_buffer_type;
+
+typedef struct grpc_byte_buffer {
+  void* reserved;
+  grpc_byte_buffer_type type;
+  union grpc_byte_buffer_data {
+    struct /* internal */ {
+      void* reserved[8];
+    } reserved;
+    struct grpc_compressed_buffer {
+      grpc_compression_algorithm compression;
+      grpc_slice_buffer slice_buffer;
+    } raw;
+  } data;
+} grpc_byte_buffer;
+
+/** Completion Queues enable notification of the completion of
+ * asynchronous actions. */
+typedef struct grpc_completion_queue grpc_completion_queue;
+
+/** An alarm associated with a completion queue. */
+typedef struct grpc_alarm grpc_alarm;
+
+/** The Channel interface allows creation of Call objects. */
+typedef struct grpc_channel grpc_channel;
+
+/** A server listens to some port and responds to request calls */
+typedef struct grpc_server grpc_server;
+
+/** A Call represents an RPC. When created, it is in a configuration state
+    allowing properties to be set until it is invoked. After invoke, the Call
+    can have messages written to it and read from it. */
+typedef struct grpc_call grpc_call;
+
+/** The Socket Mutator interface allows changes on socket options */
+typedef struct grpc_socket_mutator grpc_socket_mutator;
+
+/** The Socket Factory interface creates and binds sockets */
+typedef struct grpc_socket_factory grpc_socket_factory;
+
+/** Type specifier for grpc_arg */
+typedef enum {
+  GRPC_ARG_STRING,
+  GRPC_ARG_INTEGER,
+  GRPC_ARG_POINTER
+} grpc_arg_type;
+
+typedef struct grpc_arg_pointer_vtable {
+  void* (*copy)(void* p);
+  void (*destroy)(void* p);
+  int (*cmp)(void* p, void* q);
+} grpc_arg_pointer_vtable;
+
+/** A single argument... each argument has a key and a value
+
+    A note on naming keys:
+      Keys are namespaced into groups, usually grouped by library, and are
+      keys for module XYZ are named XYZ.key1, XYZ.key2, etc. Module names must
+      be restricted to the regex [A-Za-z][_A-Za-z0-9]{,15}.
+      Key names must be restricted to the regex [A-Za-z][_A-Za-z0-9]{,47}.
+
+    GRPC core library keys are prefixed by grpc.
+
+    Library authors are strongly encouraged to \#define symbolic constants for
+    their keys so that it's possible to change them in the future. */
+typedef struct {
+  grpc_arg_type type;
+  char* key;
+  union grpc_arg_value {
+    char* string;
+    int integer;
+    struct grpc_arg_pointer {
+      void* p;
+      const grpc_arg_pointer_vtable* vtable;
+    } pointer;
+  } value;
+} grpc_arg;
+
+/** An array of arguments that can be passed around.
+
+    Used to set optional channel-level configuration.
+    These configuration options are modelled as key-value pairs as defined
+    by grpc_arg; keys are strings to allow easy backwards-compatible extension
+    by arbitrary parties. All evaluation is performed at channel creation
+    time (i.e. the keys and values in this structure need only live through the
+    creation invocation).
+
+    However, if one of the args has grpc_arg_type==GRPC_ARG_POINTER, then the
+    grpc_arg_pointer_vtable must live until the channel args are done being
+    used by core (i.e. when the object for use with which they were passed
+    is destroyed).
+
+    See the description of the \ref grpc_arg_keys "available args" for more
+    details. */
+typedef struct {
+  size_t num_args;
+  grpc_arg* args;
+} grpc_channel_args;
+
+/** \defgroup grpc_arg_keys
+ * Channel argument keys.
+ * \{
+ */
+/** If non-zero, enable census for tracing and stats collection. */
+#define GRPC_ARG_ENABLE_CENSUS "grpc.census"
+/** If non-zero, enable load reporting. */
+#define GRPC_ARG_ENABLE_LOAD_REPORTING "grpc.loadreporting"
+/** Request that optional features default to off (regardless of what they
+    usually default to) - to enable tight control over what gets enabled */
+#define GRPC_ARG_MINIMAL_STACK "grpc.minimal_stack"
+/** Maximum number of concurrent incoming streams to allow on a http2
+    connection. Int valued. */
+#define GRPC_ARG_MAX_CONCURRENT_STREAMS "grpc.max_concurrent_streams"
+/** Maximum message length that the channel can receive. Int valued, bytes.
+    -1 means unlimited. */
+#define GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH "grpc.max_receive_message_length"
+/** \deprecated For backward compatibility.
+ * Use GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH instead. */
+#define GRPC_ARG_MAX_MESSAGE_LENGTH GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH
+/** Maximum message length that the channel can send. Int valued, bytes.
+    -1 means unlimited. */
+#define GRPC_ARG_MAX_SEND_MESSAGE_LENGTH "grpc.max_send_message_length"
+/** Maximum time that a channel may have no outstanding rpcs, after which the
+ * server will close the connection. Int valued, milliseconds. INT_MAX means
+ * unlimited. */
+#define GRPC_ARG_MAX_CONNECTION_IDLE_MS "grpc.max_connection_idle_ms"
+/** Maximum time that a channel may exist. Int valued, milliseconds.
+ * INT_MAX means unlimited. */
+#define GRPC_ARG_MAX_CONNECTION_AGE_MS "grpc.max_connection_age_ms"
+/** Grace period after the channel reaches its max age. Int valued,
+   milliseconds. INT_MAX means unlimited. */
+#define GRPC_ARG_MAX_CONNECTION_AGE_GRACE_MS "grpc.max_connection_age_grace_ms"
+/** Timeout after the last RPC finishes on the client channel at which the
+ * channel goes back into IDLE state. Int valued, milliseconds. INT_MAX means
+ * unlimited. The default value is 30 minutes and the min value is 1 second. */
+#define GRPC_ARG_CLIENT_IDLE_TIMEOUT_MS "grpc.client_idle_timeout_ms"
+/** Enable/disable support for per-message compression. Defaults to 1, unless
+    GRPC_ARG_MINIMAL_STACK is enabled, in which case it defaults to 0. */
+#define GRPC_ARG_ENABLE_PER_MESSAGE_COMPRESSION "grpc.per_message_compression"
+/** Experimental Arg. Enable/disable support for per-message decompression.
+   Defaults to 1. If disabled, decompression will not be performed and the
+   application will see the compressed message in the byte buffer. */
+#define GRPC_ARG_ENABLE_PER_MESSAGE_DECOMPRESSION \
+  "grpc.per_message_decompression"
+/** Enable/disable support for deadline checking. Defaults to 1, unless
+    GRPC_ARG_MINIMAL_STACK is enabled, in which case it defaults to 0 */
+#define GRPC_ARG_ENABLE_DEADLINE_CHECKS "grpc.enable_deadline_checking"
+/** Initial stream ID for http2 transports. Int valued. */
+#define GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER \
+  "grpc.http2.initial_sequence_number"
+/** Amount to read ahead on individual streams. Defaults to 64kb, larger
+    values can help throughput on high-latency connections.
+    NOTE: at some point we'd like to auto-tune this, and this parameter
+    will become a no-op. Int valued, bytes. */
+#define GRPC_ARG_HTTP2_STREAM_LOOKAHEAD_BYTES "grpc.http2.lookahead_bytes"
+/** How much memory to use for hpack decoding. Int valued, bytes. */
+#define GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_DECODER \
+  "grpc.http2.hpack_table_size.decoder"
+/** How much memory to use for hpack encoding. Int valued, bytes. */
+#define GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_ENCODER \
+  "grpc.http2.hpack_table_size.encoder"
+/** How big a frame are we willing to receive via HTTP2.
+    Min 16384, max 16777215. Larger values give lower CPU usage for large
+    messages, but more head of line blocking for small messages. */
+#define GRPC_ARG_HTTP2_MAX_FRAME_SIZE "grpc.http2.max_frame_size"
+/** Should BDP probing be performed? */
+#define GRPC_ARG_HTTP2_BDP_PROBE "grpc.http2.bdp_probe"
+/** (DEPRECATED) Does not have any effect.
+    Earlier, this arg configured the minimum time between successive ping frames
+    without receiving any data/header frame, Int valued, milliseconds. This put
+    unnecessary constraints on the configuration of keepalive pings,
+    requiring users to set this channel arg along with
+    GRPC_ARG_KEEPALIVE_TIME_MS. This arg also limited the activity of the other
+    source of pings in gRPC Core - BDP pings, but BDP pings are only sent when
+    there is receive-side data activity, making this arg unuseful for BDP pings
+    too.  */
+#define GRPC_ARG_HTTP2_MIN_SENT_PING_INTERVAL_WITHOUT_DATA_MS \
+  "grpc.http2.min_time_between_pings_ms"
+/** Minimum allowed time between a server receiving successive ping frames
+   without sending any data/header frame. Int valued, milliseconds
+ */
+#define GRPC_ARG_HTTP2_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS \
+  "grpc.http2.min_ping_interval_without_data_ms"
+/** Channel arg to override the http2 :scheme header */
+#define GRPC_ARG_HTTP2_SCHEME "grpc.http2_scheme"
+/** How many pings can we send before needing to send a
+   data/header frame? (0 indicates that an infinite number of
+   pings can be sent without sending a data frame or header frame) */
+#define GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA \
+  "grpc.http2.max_pings_without_data"
+/** How many misbehaving pings the server can bear before sending goaway and
+    closing the transport? (0 indicates that the server can bear an infinite
+    number of misbehaving pings) */
+#define GRPC_ARG_HTTP2_MAX_PING_STRIKES "grpc.http2.max_ping_strikes"
+/** How much data are we willing to queue up per stream if
+    GRPC_WRITE_BUFFER_HINT is set? This is an upper bound */
+#define GRPC_ARG_HTTP2_WRITE_BUFFER_SIZE "grpc.http2.write_buffer_size"
+/** Should we allow receipt of true-binary data on http2 connections?
+    Defaults to on (1) */
+#define GRPC_ARG_HTTP2_ENABLE_TRUE_BINARY "grpc.http2.true_binary"
+/** After a duration of this time the client/server pings its peer to see if the
+    transport is still alive. Int valued, milliseconds. */
+#define GRPC_ARG_KEEPALIVE_TIME_MS "grpc.keepalive_time_ms"
+/** After waiting for a duration of this time, if the keepalive ping sender does
+    not receive the ping ack, it will close the transport. Int valued,
+    milliseconds. */
+#define GRPC_ARG_KEEPALIVE_TIMEOUT_MS "grpc.keepalive_timeout_ms"
+/** Is it permissible to send keepalive pings without any outstanding streams.
+    Int valued, 0(false)/1(true). */
+#define GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS \
+  "grpc.keepalive_permit_without_calls"
+/** Default authority to pass if none specified on call construction. A string.
+ * */
+#define GRPC_ARG_DEFAULT_AUTHORITY "grpc.default_authority"
+/** Primary user agent: goes at the start of the user-agent metadata
+    sent on each request. A string. */
+#define GRPC_ARG_PRIMARY_USER_AGENT_STRING "grpc.primary_user_agent"
+/** Secondary user agent: goes at the end of the user-agent metadata
+    sent on each request. A string. */
+#define GRPC_ARG_SECONDARY_USER_AGENT_STRING "grpc.secondary_user_agent"
+/** The minimum time between subsequent connection attempts, in ms */
+#define GRPC_ARG_MIN_RECONNECT_BACKOFF_MS "grpc.min_reconnect_backoff_ms"
+/** The maximum time between subsequent connection attempts, in ms */
+#define GRPC_ARG_MAX_RECONNECT_BACKOFF_MS "grpc.max_reconnect_backoff_ms"
+/** The time between the first and second connection attempts, in ms */
+#define GRPC_ARG_INITIAL_RECONNECT_BACKOFF_MS \
+  "grpc.initial_reconnect_backoff_ms"
+/** Minimum amount of time between DNS resolutions, in ms */
+#define GRPC_ARG_DNS_MIN_TIME_BETWEEN_RESOLUTIONS_MS \
+  "grpc.dns_min_time_between_resolutions_ms"
+/** The timeout used on servers for finishing handshaking on an incoming
+    connection.  Defaults to 120 seconds. */
+#define GRPC_ARG_SERVER_HANDSHAKE_TIMEOUT_MS "grpc.server_handshake_timeout_ms"
+/** This *should* be used for testing only.
+    The caller of the secure_channel_create functions may override the target
+    name used for SSL host name checking using this channel argument which is of
+    type \a GRPC_ARG_STRING. If this argument is not specified, the name used
+    for SSL host name checking will be the target parameter (assuming that the
+    secure channel is an SSL channel). If this parameter is specified and the
+    underlying is not an SSL channel, it will just be ignored. */
+#define GRPC_SSL_TARGET_NAME_OVERRIDE_ARG "grpc.ssl_target_name_override"
+/** If non-zero, a pointer to a session cache (a pointer of type
+    grpc_ssl_session_cache*). (use grpc_ssl_session_cache_arg_vtable() to fetch
+    an appropriate pointer arg vtable) */
+#define GRPC_SSL_SESSION_CACHE_ARG "grpc.ssl_session_cache"
+/** If non-zero, it will determine the maximum frame size used by TSI's frame
+ *  protector.
+ *
+ *  NOTE: Be aware that using a large "max_frame_size" is memory inefficient
+ *        for non-zerocopy protectors. Also, increasing this value above 1MiB
+ *        can break old binaries that don't support larger than 1MiB frame
+ *        size. */
+#define GRPC_ARG_TSI_MAX_FRAME_SIZE "grpc.tsi.max_frame_size"
+/** Maximum metadata size, in bytes. Note this limit applies to the max sum of
+    all metadata key-value entries in a batch of headers. */
+#define GRPC_ARG_MAX_METADATA_SIZE "grpc.max_metadata_size"
+/** If non-zero, allow the use of SO_REUSEPORT if it's available (default 1) */
+#define GRPC_ARG_ALLOW_REUSEPORT "grpc.so_reuseport"
+/** If non-zero, a pointer to a buffer pool (a pointer of type
+ * grpc_resource_quota*). (use grpc_resource_quota_arg_vtable() to fetch an
+ * appropriate pointer arg vtable) */
+#define GRPC_ARG_RESOURCE_QUOTA "grpc.resource_quota"
+/** If non-zero, expand wildcard addresses to a list of local addresses. */
+#define GRPC_ARG_EXPAND_WILDCARD_ADDRS "grpc.expand_wildcard_addrs"
+/** Service config data in JSON form.
+    This value will be ignored if the name resolver returns a service config. */
+#define GRPC_ARG_SERVICE_CONFIG "grpc.service_config"
+/** Disable looking up the service config via the name resolver. */
+#define GRPC_ARG_SERVICE_CONFIG_DISABLE_RESOLUTION \
+  "grpc.service_config_disable_resolution"
+/** LB policy name. */
+#define GRPC_ARG_LB_POLICY_NAME "grpc.lb_policy_name"
+/** The grpc_socket_mutator instance that set the socket options. A pointer. */
+#define GRPC_ARG_SOCKET_MUTATOR "grpc.socket_mutator"
+/** The grpc_socket_factory instance to create and bind sockets. A pointer. */
+#define GRPC_ARG_SOCKET_FACTORY "grpc.socket_factory"
+/** The maximum amount of memory used by trace events per channel trace node.
+ * Once the maximum is reached, subsequent events will evict the oldest events
+ * from the buffer. The unit for this knob is bytes. Setting it to zero causes
+ * channel tracing to be disabled. */
+#define GRPC_ARG_MAX_CHANNEL_TRACE_EVENT_MEMORY_PER_NODE \
+  "grpc.max_channel_trace_event_memory_per_node"
+/** If non-zero, gRPC library will track stats and information at at per channel
+ * level. Disabling channelz naturally disables channel tracing. The default
+ * is for channelz to be enabled. */
+#define GRPC_ARG_ENABLE_CHANNELZ "grpc.enable_channelz"
+/** If non-zero, Cronet transport will coalesce packets to fewer frames
+ * when possible. */
+#define GRPC_ARG_USE_CRONET_PACKET_COALESCING \
+  "grpc.use_cronet_packet_coalescing"
+/** Channel arg (integer) setting how large a slice to try and read from the
+   wire each time recvmsg (or equivalent) is called **/
+#define GRPC_ARG_TCP_READ_CHUNK_SIZE "grpc.experimental.tcp_read_chunk_size"
+/** Note this is not a "channel arg" key. This is the default slice size to use
+ * when trying to read from the wire if the GRPC_ARG_TCP_READ_CHUNK_SIZE
+ * channel arg is unspecified. */
+#define GRPC_TCP_DEFAULT_READ_SLICE_SIZE 8192
+#define GRPC_ARG_TCP_MIN_READ_CHUNK_SIZE \
+  "grpc.experimental.tcp_min_read_chunk_size"
+#define GRPC_ARG_TCP_MAX_READ_CHUNK_SIZE \
+  "grpc.experimental.tcp_max_read_chunk_size"
+/* TCP TX Zerocopy enable state: zero is disabled, non-zero is enabled. By
+   default, it is disabled. */
+#define GRPC_ARG_TCP_TX_ZEROCOPY_ENABLED \
+  "grpc.experimental.tcp_tx_zerocopy_enabled"
+/* TCP TX Zerocopy send threshold: only zerocopy if >= this many bytes sent. By
+   default, this is set to 16KB. */
+#define GRPC_ARG_TCP_TX_ZEROCOPY_SEND_BYTES_THRESHOLD \
+  "grpc.experimental.tcp_tx_zerocopy_send_bytes_threshold"
+/* TCP TX Zerocopy max simultaneous sends: limit for maximum number of pending
+   calls to tcp_write() using zerocopy. A tcp_write() is considered pending
+   until the kernel performs the zerocopy-done callback for all sendmsg() calls
+   issued by the tcp_write(). By default, this is set to 4. */
+#define GRPC_ARG_TCP_TX_ZEROCOPY_MAX_SIMULT_SENDS \
+  "grpc.experimental.tcp_tx_zerocopy_max_simultaneous_sends"
+/* Timeout in milliseconds to use for calls to the grpclb load balancer.
+   If 0 or unset, the balancer calls will have no deadline. */
+#define GRPC_ARG_GRPCLB_CALL_TIMEOUT_MS "grpc.grpclb_call_timeout_ms"
+/* Timeout in milliseconds to wait for the serverlist from the grpclb load
+   balancer before using fallback backend addresses from the resolver.
+   If 0, enter fallback mode immediately. Default value is 10000. */
+#define GRPC_ARG_GRPCLB_FALLBACK_TIMEOUT_MS "grpc.grpclb_fallback_timeout_ms"
+/* Timeout in milliseconds to wait for the child of a specific priority to
+   complete its initial connection attempt before the priority LB policy fails
+   over to the next priority. Default value is 10 seconds. */
+#define GRPC_ARG_PRIORITY_FAILOVER_TIMEOUT_MS \
+  "grpc.priority_failover_timeout_ms"
+/** If non-zero, grpc server's cronet compression workaround will be enabled */
+#define GRPC_ARG_WORKAROUND_CRONET_COMPRESSION \
+  "grpc.workaround.cronet_compression"
+/** String defining the optimization target for a channel.
+    Can be: "latency"    - attempt to minimize latency at the cost of throughput
+            "blend"      - try to balance latency and throughput
+            "throughput" - attempt to maximize throughput at the expense of
+                           latency
+    Defaults to "blend". In the current implementation "blend" is equivalent to
+    "latency". */
+#define GRPC_ARG_OPTIMIZATION_TARGET "grpc.optimization_target"
+/** If set to zero, disables retry behavior. Otherwise, transparent retries
+    are enabled for all RPCs, and configurable retries are enabled when they
+    are configured via the service config. For details, see:
+      https://github.com/grpc/proposal/blob/master/A6-client-retries.md
+ */
+#define GRPC_ARG_ENABLE_RETRIES "grpc.enable_retries"
+/** Per-RPC retry buffer size, in bytes. Default is 256 KiB. */
+#define GRPC_ARG_PER_RPC_RETRY_BUFFER_SIZE "grpc.per_rpc_retry_buffer_size"
+/** Channel arg that carries the bridged objective c object for custom metrics
+ * logging filter. */
+#define GRPC_ARG_MOBILE_LOG_CONTEXT "grpc.mobile_log_context"
+/** If non-zero, client authority filter is disabled for the channel */
+#define GRPC_ARG_DISABLE_CLIENT_AUTHORITY_FILTER \
+  "grpc.disable_client_authority_filter"
+/** If set to zero, disables use of http proxies. Enabled by default. */
+#define GRPC_ARG_ENABLE_HTTP_PROXY "grpc.enable_http_proxy"
+/** Channel arg to set http proxy per channel. If set, the channel arg
+ *  value will be prefered over the envrionment variable settings. */
+#define GRPC_ARG_HTTP_PROXY "grpc.http_proxy"
+/** If set to non zero, surfaces the user agent string to the server. User
+    agent is surfaced by default. */
+#define GRPC_ARG_SURFACE_USER_AGENT "grpc.surface_user_agent"
+/** If set, inhibits health checking (which may be enabled via the
+ *  service config.) */
+#define GRPC_ARG_INHIBIT_HEALTH_CHECKING "grpc.inhibit_health_checking"
+/** If set, the channel's resolver is allowed to query for SRV records.
+ * For example, this is useful as a way to enable the "grpclb"
+ * load balancing policy. Note that this only works with the "ares"
+ * DNS resolver, and isn't supported by the "native" DNS resolver. */
+#define GRPC_ARG_DNS_ENABLE_SRV_QUERIES "grpc.dns_enable_srv_queries"
+/** If set, determines an upper bound on the number of milliseconds that the
+ * c-ares based DNS resolver will wait on queries before cancelling them.
+ * The default value is 120,000. Setting this to "0" will disable the
+ * overall timeout entirely. Note that this doesn't include internal c-ares
+ * timeouts/backoff/retry logic, and so the actual DNS resolution may time out
+ * sooner than the value specified here. */
+#define GRPC_ARG_DNS_ARES_QUERY_TIMEOUT_MS "grpc.dns_ares_query_timeout"
+/** If set, uses a local subchannel pool within the channel. Otherwise, uses the
+ * global subchannel pool. */
+#define GRPC_ARG_USE_LOCAL_SUBCHANNEL_POOL "grpc.use_local_subchannel_pool"
+/** gRPC Objective-C channel pooling domain string. */
+#define GRPC_ARG_CHANNEL_POOL_DOMAIN "grpc.channel_pooling_domain"
+/** gRPC Objective-C channel pooling id. */
+#define GRPC_ARG_CHANNEL_ID "grpc.channel_id"
+/** \} */
+
+/** Result of a grpc call. If the caller satisfies the prerequisites of a
+    particular operation, the grpc_call_error returned will be GRPC_CALL_OK.
+    Receiving any other value listed here is an indication of a bug in the
+    caller. */
+typedef enum grpc_call_error {
+  /** everything went ok */
+  GRPC_CALL_OK = 0,
+  /** something failed, we don't know what */
+  GRPC_CALL_ERROR,
+  /** this method is not available on the server */
+  GRPC_CALL_ERROR_NOT_ON_SERVER,
+  /** this method is not available on the client */
+  GRPC_CALL_ERROR_NOT_ON_CLIENT,
+  /** this method must be called before server_accept */
+  GRPC_CALL_ERROR_ALREADY_ACCEPTED,
+  /** this method must be called before invoke */
+  GRPC_CALL_ERROR_ALREADY_INVOKED,
+  /** this method must be called after invoke */
+  GRPC_CALL_ERROR_NOT_INVOKED,
+  /** this call is already finished
+      (writes_done or write_status has already been called) */
+  GRPC_CALL_ERROR_ALREADY_FINISHED,
+  /** there is already an outstanding read/write operation on the call */
+  GRPC_CALL_ERROR_TOO_MANY_OPERATIONS,
+  /** the flags value was illegal for this call */
+  GRPC_CALL_ERROR_INVALID_FLAGS,
+  /** invalid metadata was passed to this call */
+  GRPC_CALL_ERROR_INVALID_METADATA,
+  /** invalid message was passed to this call */
+  GRPC_CALL_ERROR_INVALID_MESSAGE,
+  /** completion queue for notification has not been registered
+   * with the server */
+  GRPC_CALL_ERROR_NOT_SERVER_COMPLETION_QUEUE,
+  /** this batch of operations leads to more operations than allowed */
+  GRPC_CALL_ERROR_BATCH_TOO_BIG,
+  /** payload type requested is not the type registered */
+  GRPC_CALL_ERROR_PAYLOAD_TYPE_MISMATCH,
+  /** completion queue has been shutdown */
+  GRPC_CALL_ERROR_COMPLETION_QUEUE_SHUTDOWN
+} grpc_call_error;
+
+/** Default send/receive message size limits in bytes. -1 for unlimited. */
+/** TODO(roth) Make this match the default receive limit after next release */
+#define GRPC_DEFAULT_MAX_SEND_MESSAGE_LENGTH (-1)
+#define GRPC_DEFAULT_MAX_RECV_MESSAGE_LENGTH (4 * 1024 * 1024)
+
+/** Write Flags: */
+/** Hint that the write may be buffered and need not go out on the wire
+    immediately. GRPC is free to buffer the message until the next non-buffered
+    write, or until writes_done, but it need not buffer completely or at all. */
+#define GRPC_WRITE_BUFFER_HINT (0x00000001u)
+/** Force compression to be disabled for a particular write
+    (start_write/add_metadata). Illegal on invoke/accept. */
+#define GRPC_WRITE_NO_COMPRESS (0x00000002u)
+/** Force this message to be written to the socket before completing it */
+#define GRPC_WRITE_THROUGH (0x00000004u)
+/** Mask of all valid flags. */
+#define GRPC_WRITE_USED_MASK \
+  (GRPC_WRITE_BUFFER_HINT | GRPC_WRITE_NO_COMPRESS | GRPC_WRITE_THROUGH)
+
+/** Initial metadata flags */
+/** Signal that the call is idempotent */
+#define GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST (0x00000010u)
+/** Signal that the call should not return UNAVAILABLE before it has started */
+#define GRPC_INITIAL_METADATA_WAIT_FOR_READY (0x00000020u)
+/** Signal that the call is cacheable. GRPC is free to use GET verb */
+#define GRPC_INITIAL_METADATA_CACHEABLE_REQUEST (0x00000040u)
+/** Signal that GRPC_INITIAL_METADATA_WAIT_FOR_READY was explicitly set
+    by the calling application. */
+#define GRPC_INITIAL_METADATA_WAIT_FOR_READY_EXPLICITLY_SET (0x00000080u)
+/** Signal that the initial metadata should be corked */
+#define GRPC_INITIAL_METADATA_CORKED (0x00000100u)
+
+/** Mask of all valid flags */
+#define GRPC_INITIAL_METADATA_USED_MASK                  \
+  (GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST |            \
+   GRPC_INITIAL_METADATA_WAIT_FOR_READY |                \
+   GRPC_INITIAL_METADATA_CACHEABLE_REQUEST |             \
+   GRPC_INITIAL_METADATA_WAIT_FOR_READY_EXPLICITLY_SET | \
+   GRPC_INITIAL_METADATA_CORKED | GRPC_WRITE_THROUGH)
+
+/** A single metadata element */
+typedef struct grpc_metadata {
+  /** the key, value values are expected to line up with grpc_mdelem: if
+     changing them, update metadata.h at the same time. */
+  grpc_slice key;
+  grpc_slice value;
+
+  uint32_t flags;
+
+  /** The following fields are reserved for grpc internal use.
+      There is no need to initialize them, and they will be set to garbage
+      during calls to grpc. */
+  struct /* internal */ {
+    void* obfuscated[4];
+  } internal_data;
+} grpc_metadata;
+
+/** The type of completion (for grpc_event) */
+typedef enum grpc_completion_type {
+  /** Shutting down */
+  GRPC_QUEUE_SHUTDOWN,
+  /** No event before timeout */
+  GRPC_QUEUE_TIMEOUT,
+  /** Operation completion */
+  GRPC_OP_COMPLETE
+} grpc_completion_type;
+
+/** The result of an operation.
+
+    Returned by a completion queue when the operation started with tag. */
+typedef struct grpc_event {
+  /** The type of the completion. */
+  grpc_completion_type type;
+  /** If the grpc_completion_type is GRPC_OP_COMPLETE, this field indicates
+      whether the operation was successful or not; 0 in case of failure and
+      non-zero in case of success.
+      If grpc_completion_type is GRPC_QUEUE_SHUTDOWN or GRPC_QUEUE_TIMEOUT, this
+      field is guaranteed to be 0 */
+  int success;
+  /** The tag passed to grpc_call_start_batch etc to start this operation.
+      *Only* GRPC_OP_COMPLETE has a tag. For all other grpc_completion_type
+      values, tag is uninitialized. */
+  void* tag;
+} grpc_event;
+
+typedef struct {
+  size_t count;
+  size_t capacity;
+  grpc_metadata* metadata;
+} grpc_metadata_array;
+
+typedef struct {
+  grpc_slice method;
+  grpc_slice host;
+  gpr_timespec deadline;
+  uint32_t flags;
+  void* reserved;
+} grpc_call_details;
+
+typedef enum {
+  /** Send initial metadata: one and only one instance MUST be sent for each
+      call, unless the call was cancelled - in which case this can be skipped.
+      This op completes after all bytes of metadata have been accepted by
+      outgoing flow control. */
+  GRPC_OP_SEND_INITIAL_METADATA = 0,
+  /** Send a message: 0 or more of these operations can occur for each call.
+      This op completes after all bytes for the message have been accepted by
+      outgoing flow control. */
+  GRPC_OP_SEND_MESSAGE,
+  /** Send a close from the client: one and only one instance MUST be sent from
+      the client, unless the call was cancelled - in which case this can be
+      skipped. This op completes after all bytes for the call
+      (including the close) have passed outgoing flow control. */
+  GRPC_OP_SEND_CLOSE_FROM_CLIENT,
+  /** Send status from the server: one and only one instance MUST be sent from
+      the server unless the call was cancelled - in which case this can be
+      skipped. This op completes after all bytes for the call
+      (including the status) have passed outgoing flow control. */
+  GRPC_OP_SEND_STATUS_FROM_SERVER,
+  /** Receive initial metadata: one and only one MUST be made on the client,
+      must not be made on the server.
+      This op completes after all initial metadata has been read from the
+      peer. */
+  GRPC_OP_RECV_INITIAL_METADATA,
+  /** Receive a message: 0 or more of these operations can occur for each call.
+      This op completes after all bytes of the received message have been
+      read, or after a half-close has been received on this call. */
+  GRPC_OP_RECV_MESSAGE,
+  /** Receive status on the client: one and only one must be made on the client.
+      This operation always succeeds, meaning ops paired with this operation
+      will also appear to succeed, even though they may not have. In that case
+      the status will indicate some failure.
+      This op completes after all activity on the call has completed. */
+  GRPC_OP_RECV_STATUS_ON_CLIENT,
+  /** Receive close on the server: one and only one must be made on the
+      server. This op completes after the close has been received by the
+      server. This operation always succeeds, meaning ops paired with
+      this operation will also appear to succeed, even though they may not
+      have. */
+  GRPC_OP_RECV_CLOSE_ON_SERVER
+} grpc_op_type;
+
+struct grpc_byte_buffer;
+
+/** Operation data: one field for each op type (except SEND_CLOSE_FROM_CLIENT
+   which has no arguments) */
+typedef struct grpc_op {
+  /** Operation type, as defined by grpc_op_type */
+  grpc_op_type op;
+  /** Write flags bitset for grpc_begin_messages */
+  uint32_t flags;
+  /** Reserved for future usage */
+  void* reserved;
+  union grpc_op_data {
+    /** Reserved for future usage */
+    struct /* internal */ {
+      void* reserved[8];
+    } reserved;
+    struct grpc_op_send_initial_metadata {
+      size_t count;
+      grpc_metadata* metadata;
+      /** If \a is_set, \a compression_level will be used for the call.
+       * Otherwise, \a compression_level won't be considered */
+      struct grpc_op_send_initial_metadata_maybe_compression_level {
+        uint8_t is_set;
+        grpc_compression_level level;
+      } maybe_compression_level;
+    } send_initial_metadata;
+    struct grpc_op_send_message {
+      /** This op takes ownership of the slices in send_message.  After
+       * a call completes, the contents of send_message are not guaranteed
+       * and likely empty.  The original owner should still call
+       * grpc_byte_buffer_destroy() on this object however.
+       */
+      struct grpc_byte_buffer* send_message;
+    } send_message;
+    struct grpc_op_send_status_from_server {
+      size_t trailing_metadata_count;
+      grpc_metadata* trailing_metadata;
+      grpc_status_code status;
+      /** optional: set to NULL if no details need sending, non-NULL if they do
+       * pointer will not be retained past the start_batch call
+       */
+      grpc_slice* status_details;
+    } send_status_from_server;
+    /** ownership of the array is with the caller, but ownership of the elements
+        stays with the call object (ie key, value members are owned by the call
+        object, recv_initial_metadata->array is owned by the caller).
+        After the operation completes, call grpc_metadata_array_destroy on this
+        value, or reuse it in a future op. */
+    struct grpc_op_recv_initial_metadata {
+      grpc_metadata_array* recv_initial_metadata;
+    } recv_initial_metadata;
+    /** ownership of the byte buffer is moved to the caller; the caller must
+        call grpc_byte_buffer_destroy on this value, or reuse it in a future op.
+        The returned byte buffer will be NULL if trailing metadata was
+        received instead of a message.
+       */
+    struct grpc_op_recv_message {
+      struct grpc_byte_buffer** recv_message;
+    } recv_message;
+    struct grpc_op_recv_status_on_client {
+      /** ownership of the array is with the caller, but ownership of the
+          elements stays with the call object (ie key, value members are owned
+          by the call object, trailing_metadata->array is owned by the caller).
+          After the operation completes, call grpc_metadata_array_destroy on
+          this value, or reuse it in a future op. */
+      grpc_metadata_array* trailing_metadata;
+      grpc_status_code* status;
+      grpc_slice* status_details;
+      /** If this is not nullptr, it will be populated with the full fidelity
+       * error string for debugging purposes. The application is responsible
+       * for freeing the data by using gpr_free(). */
+      const char** error_string;
+    } recv_status_on_client;
+    struct grpc_op_recv_close_on_server {
+      /** out argument, set to 1 if the call failed at the server for
+          a reason other than a non-OK status (cancel, deadline
+          exceeded, network failure, etc.), 0 otherwise (RPC processing ran to
+          completion and was able to provide any status from the server) */
+      int* cancelled;
+    } recv_close_on_server;
+  } data;
+} grpc_op;
+
+/** Information requested from the channel. */
+typedef struct {
+  /** If non-NULL, will be set to point to a string indicating the LB
+   * policy name.  Caller takes ownership. */
+  char** lb_policy_name;
+  /** If non-NULL, will be set to point to a string containing the
+   * service config used by the channel in JSON form. */
+  char** service_config_json;
+} grpc_channel_info;
+
+typedef struct grpc_resource_quota grpc_resource_quota;
+
+/** Completion queues internally MAY maintain a set of file descriptors in a
+    structure called 'pollset'. This enum specifies if a completion queue has an
+    associated pollset and any restrictions on the type of file descriptors that
+    can be present in the pollset.
+
+    I/O progress can only be made when grpc_completion_queue_next() or
+    grpc_completion_queue_pluck() are called on the completion queue (unless the
+    grpc_cq_polling_type is GRPC_CQ_NON_POLLING) and hence it is very important
+    to actively call these APIs */
+typedef enum {
+  /** The completion queue will have an associated pollset and there is no
+      restriction on the type of file descriptors the pollset may contain */
+  GRPC_CQ_DEFAULT_POLLING,
+
+  /** Similar to GRPC_CQ_DEFAULT_POLLING except that the completion queues will
+      not contain any 'listening file descriptors' (i.e file descriptors used to
+      listen to incoming channels) */
+  GRPC_CQ_NON_LISTENING,
+
+  /** The completion queue will not have an associated pollset. Note that
+      grpc_completion_queue_next() or grpc_completion_queue_pluck() MUST still
+      be called to pop events from the completion queue; it is not required to
+      call them actively to make I/O progress */
+  GRPC_CQ_NON_POLLING
+} grpc_cq_polling_type;
+
+/** Specifies the type of APIs to use to pop events from the completion queue */
+typedef enum {
+  /** Events are popped out by calling grpc_completion_queue_next() API ONLY */
+  GRPC_CQ_NEXT,
+
+  /** Events are popped out by calling grpc_completion_queue_pluck() API ONLY*/
+  GRPC_CQ_PLUCK,
+
+  /** EXPERIMENTAL: Events trigger a callback specified as the tag */
+  GRPC_CQ_CALLBACK
+} grpc_cq_completion_type;
+
+/** EXPERIMENTAL: Specifies an interface class to be used as a tag
+    for callback-based completion queues. This can be used directly,
+    as the first element of a struct in C, or as a base class in C++.
+    Its "run" value should be assigned to some non-member function, such as
+    a static method. */
+typedef struct grpc_experimental_completion_queue_functor {
+  /** The run member specifies a function that will be called when this
+      tag is extracted from the completion queue. Its arguments will be a
+      pointer to this functor and a boolean that indicates whether the
+      operation succeeded (non-zero) or failed (zero) */
+  void (*functor_run)(struct grpc_experimental_completion_queue_functor*, int);
+
+  /** The inlineable member specifies whether this functor can be run inline.
+      This should only be used for trivial internally-defined functors. */
+  int inlineable;
+
+  /** The following fields are not API. They are meant for internal use. */
+  int internal_success;
+  struct grpc_experimental_completion_queue_functor* internal_next;
+} grpc_experimental_completion_queue_functor;
+
+/* The upgrade to version 2 is currently experimental. */
+
+#define GRPC_CQ_CURRENT_VERSION 2
+#define GRPC_CQ_VERSION_MINIMUM_FOR_CALLBACKABLE 2
+typedef struct grpc_completion_queue_attributes {
+  /** The version number of this structure. More fields might be added to this
+     structure in future. */
+  int version; /** Set to GRPC_CQ_CURRENT_VERSION */
+
+  grpc_cq_completion_type cq_completion_type;
+
+  grpc_cq_polling_type cq_polling_type;
+
+  /* END OF VERSION 1 CQ ATTRIBUTES */
+
+  /* EXPERIMENTAL: START OF VERSION 2 CQ ATTRIBUTES */
+  /** When creating a callbackable CQ, pass in a functor to get invoked when
+   * shutdown is complete */
+  grpc_experimental_completion_queue_functor* cq_shutdown_cb;
+
+  /* END OF VERSION 2 CQ ATTRIBUTES */
+} grpc_completion_queue_attributes;
+
+/** The completion queue factory structure is opaque to the callers of grpc */
+typedef struct grpc_completion_queue_factory grpc_completion_queue_factory;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_GRPC_TYPES_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/log.h b/grpc/spm-core-include/grpc/impl/codegen/log.h
new file mode 100644
index 00000000..9dd3a518
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/log.h
@@ -0,0 +1,110 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_LOG_H
+#define GRPC_IMPL_CODEGEN_LOG_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <stdarg.h>
+#include <stdlib.h> /* for abort() */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** GPR log API.
+
+   Usage (within grpc):
+
+   int argument1 = 3;
+   char* argument2 = "hello";
+   gpr_log(GPR_DEBUG, "format string %d", argument1);
+   gpr_log(GPR_INFO, "hello world");
+   gpr_log(GPR_ERROR, "%d %s!!", argument1, argument2); */
+
+/** The severity of a log message - use the #defines below when calling into
+   gpr_log to additionally supply file and line data */
+typedef enum gpr_log_severity {
+  GPR_LOG_SEVERITY_DEBUG,
+  GPR_LOG_SEVERITY_INFO,
+  GPR_LOG_SEVERITY_ERROR
+} gpr_log_severity;
+
+/** Returns a string representation of the log severity */
+GPRAPI const char* gpr_log_severity_string(gpr_log_severity severity);
+
+/** Macros to build log contexts at various severity levels */
+#define GPR_DEBUG __FILE__, __LINE__, GPR_LOG_SEVERITY_DEBUG
+#define GPR_INFO __FILE__, __LINE__, GPR_LOG_SEVERITY_INFO
+#define GPR_ERROR __FILE__, __LINE__, GPR_LOG_SEVERITY_ERROR
+
+/** Log a message. It's advised to use GPR_xxx above to generate the context
+ * for each message */
+GPRAPI void gpr_log(const char* file, int line, gpr_log_severity severity,
+                    const char* format, ...) GPR_PRINT_FORMAT_CHECK(4, 5);
+
+GPRAPI int gpr_should_log(gpr_log_severity severity);
+
+GPRAPI void gpr_log_message(const char* file, int line,
+                            gpr_log_severity severity, const char* message);
+
+/** Set global log verbosity */
+GPRAPI void gpr_set_log_verbosity(gpr_log_severity min_severity_to_print);
+
+GPRAPI void gpr_log_verbosity_init(void);
+
+/** Log overrides: applications can use this API to intercept logging calls
+   and use their own implementations */
+
+struct gpr_log_func_args {
+  const char* file;
+  int line;
+  gpr_log_severity severity;
+  const char* message;
+};
+
+typedef struct gpr_log_func_args gpr_log_func_args;
+
+typedef void (*gpr_log_func)(gpr_log_func_args* args);
+GPRAPI void gpr_set_log_function(gpr_log_func func);
+
+/** abort() the process if x is zero, having written a line to the log.
+
+   Intended for internal invariants.  If the error can be recovered from,
+   without the possibility of corruption, or might best be reflected via
+   an exception in a higher-level language, consider returning error code.  */
+#define GPR_ASSERT(x)                                 \
+  do {                                                \
+    if (GPR_UNLIKELY(!(x))) {                         \
+      gpr_log(GPR_ERROR, "assertion failed: %s", #x); \
+      abort();                                        \
+    }                                                 \
+  } while (0)
+
+#ifndef NDEBUG
+#define GPR_DEBUG_ASSERT(x) GPR_ASSERT(x)
+#else
+#define GPR_DEBUG_ASSERT(x)
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_LOG_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/port_platform.h b/grpc/spm-core-include/grpc/impl/codegen/port_platform.h
new file mode 100644
index 00000000..c1bada11
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/port_platform.h
@@ -0,0 +1,660 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_PORT_PLATFORM_H
+#define GRPC_IMPL_CODEGEN_PORT_PLATFORM_H
+
+/*
+ * Define GPR_BACKWARDS_COMPATIBILITY_MODE to try harder to be ABI
+ * compatible with older platforms (currently only on Linux)
+ * Causes:
+ *  - some libc calls to be gotten via dlsym
+ *  - some syscalls to be made directly
+ */
+
+/*
+ * Defines GPR_ABSEIL_SYNC to use synchronization features from Abseil
+ */
+#ifndef GPR_ABSEIL_SYNC
+#if defined(__APPLE__)
+// This is disabled on Apple platforms because macos/grpc_basictests_c_cpp
+// fails with this. https://github.com/grpc/grpc/issues/23661
+#else
+#define GPR_ABSEIL_SYNC 1
+#endif
+#endif  // GPR_ABSEIL_SYNC
+
+/* Get windows.h included everywhere (we need it) */
+#if defined(_WIN64) || defined(WIN64) || defined(_WIN32) || defined(WIN32)
+#ifndef WIN32_LEAN_AND_MEAN
+#define GRPC_WIN32_LEAN_AND_MEAN_WAS_NOT_DEFINED
+#define WIN32_LEAN_AND_MEAN
+#endif /* WIN32_LEAN_AND_MEAN */
+
+#ifndef NOMINMAX
+#define GRPC_NOMINMX_WAS_NOT_DEFINED
+#define NOMINMAX
+#endif /* NOMINMAX */
+
+#include <windows.h>
+
+#ifndef _WIN32_WINNT
+#error \
+    "Please compile grpc with _WIN32_WINNT of at least 0x600 (aka Windows Vista)"
+#else /* !defined(_WIN32_WINNT) */
+#if (_WIN32_WINNT < 0x0600)
+#error \
+    "Please compile grpc with _WIN32_WINNT of at least 0x600 (aka Windows Vista)"
+#endif /* _WIN32_WINNT < 0x0600 */
+#endif /* defined(_WIN32_WINNT) */
+
+#ifdef GRPC_WIN32_LEAN_AND_MEAN_WAS_NOT_DEFINED
+#undef GRPC_WIN32_LEAN_AND_MEAN_WAS_NOT_DEFINED
+#undef WIN32_LEAN_AND_MEAN
+#endif /* GRPC_WIN32_LEAN_AND_MEAN_WAS_NOT_DEFINED */
+
+#ifdef GRPC_NOMINMAX_WAS_NOT_DEFINED
+#undef GRPC_NOMINMAX_WAS_NOT_DEFINED
+#undef NOMINMAX
+#endif /* GRPC_WIN32_LEAN_AND_MEAN_WAS_NOT_DEFINED */
+#endif /* defined(_WIN64) || defined(WIN64) || defined(_WIN32) || \
+          defined(WIN32) */
+
+/* Override this file with one for your platform if you need to redefine
+   things.  */
+
+#if !defined(GPR_NO_AUTODETECT_PLATFORM)
+#if defined(_WIN64) || defined(WIN64) || defined(_WIN32) || defined(WIN32)
+#if defined(_WIN64) || defined(WIN64)
+#define GPR_ARCH_64 1
+#else
+#define GPR_ARCH_32 1
+#endif
+#define GPR_PLATFORM_STRING "windows"
+#define GPR_WINDOWS 1
+#define GPR_WINDOWS_SUBPROCESS 1
+#define GPR_WINDOWS_ENV
+#ifdef __MSYS__
+#define GPR_GETPID_IN_UNISTD_H 1
+#define GPR_MSYS_TMPFILE
+#define GPR_POSIX_LOG
+#define GPR_POSIX_STRING
+#define GPR_POSIX_TIME
+#else
+#define GPR_GETPID_IN_PROCESS_H 1
+#define GPR_WINDOWS_TMPFILE
+#define GPR_WINDOWS_LOG
+#define GPR_WINDOWS_CRASH_HANDLER 1
+#define GPR_WINDOWS_STAT
+#define GPR_WINDOWS_STRING
+#define GPR_WINDOWS_TIME
+#endif
+#ifdef __GNUC__
+#define GPR_GCC_ATOMIC 1
+#else
+#define GPR_WINDOWS_ATOMIC 1
+#endif
+#define GPR_STDCPP_TLS 1
+#elif defined(ANDROID) || defined(__ANDROID__)
+#define GPR_PLATFORM_STRING "android"
+#define GPR_ANDROID 1
+// TODO(apolcyn): re-evaluate support for c-ares
+// on android after upgrading our c-ares dependency.
+// See https://github.com/grpc/grpc/issues/18038.
+#define GRPC_ARES 0
+#ifdef _LP64
+#define GPR_ARCH_64 1
+#else /* _LP64 */
+#define GPR_ARCH_32 1
+#endif /* _LP64 */
+#define GPR_CPU_POSIX 1
+#define GPR_GCC_SYNC 1
+#define GPR_STDCPP_TLS 1
+#define GPR_POSIX_ENV 1
+#define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
+#define GPR_ANDROID_LOG 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_SUBPROCESS 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_TIME 1
+#define GPR_HAS_PTHREAD_H 1
+#define GPR_GETPID_IN_UNISTD_H 1
+#define GPR_SUPPORT_CHANNELS_FROM_FD 1
+#elif defined(__linux__)
+#define GPR_PLATFORM_STRING "linux"
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE
+#endif
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE
+#endif
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <features.h>
+#define GPR_CPU_LINUX 1
+#define GPR_GCC_ATOMIC 1
+#define GPR_STDCPP_TLS 1
+#define GPR_LINUX 1
+#define GPR_LINUX_LOG
+#define GPR_SUPPORT_CHANNELS_FROM_FD 1
+#define GPR_LINUX_ENV 1
+#define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_SUBPROCESS 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_TIME 1
+#define GPR_HAS_PTHREAD_H 1
+#define GPR_GETPID_IN_UNISTD_H 1
+#ifdef _LP64
+#define GPR_ARCH_64 1
+#else /* _LP64 */
+#define GPR_ARCH_32 1
+#endif /* _LP64 */
+#ifdef __GLIBC__
+#define GPR_POSIX_CRASH_HANDLER 1
+#define GPR_LINUX_PTHREAD_NAME 1
+#include <linux/version.h>
+#else /* musl libc */
+#define GPR_MUSL_LIBC_COMPAT 1
+#endif
+#elif defined(__ASYLO__)
+#define GPR_ARCH_64 1
+#define GPR_CPU_POSIX 1
+#define GPR_GCC_TLS 1
+#define GPR_PLATFORM_STRING "asylo"
+#define GPR_GCC_SYNC 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_LOG 1
+#define GPR_POSIX_TIME 1
+#define GPR_POSIX_ENV 1
+#define GPR_ASYLO 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_TIMER_USE_GENERIC 1
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#define GRPC_POSIX_WAKEUP_FD 1
+#define GRPC_ARES 0
+#define GPR_NO_AUTODETECT_PLATFORM 1
+#elif defined(__APPLE__)
+#include <Availability.h>
+#include <TargetConditionals.h>
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE
+#endif
+#if TARGET_OS_IPHONE
+#define GPR_PLATFORM_STRING "ios"
+#define GPR_CPU_IPHONE 1
+#define GRPC_CFSTREAM 1
+/* the c-ares resolver isn't safe to enable on iOS */
+#define GRPC_ARES 0
+#else /* TARGET_OS_IPHONE */
+#define GPR_PLATFORM_STRING "osx"
+#define GPR_CPU_POSIX 1
+#define GPR_POSIX_CRASH_HANDLER 1
+#endif
+#ifdef __has_feature
+#if __has_feature(cxx_thread_local)
+#define GPR_STDCPP_TLS 1
+#endif
+#endif
+#ifndef GPR_STDCPP_TLS
+#define GPR_PTHREAD_TLS 1
+#endif
+#define GPR_APPLE 1
+#define GPR_GCC_ATOMIC 1
+#define GPR_POSIX_LOG 1
+#define GPR_POSIX_ENV 1
+#define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_SUBPROCESS 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_TIME 1
+#define GPR_HAS_PTHREAD_H 1
+#define GPR_GETPID_IN_UNISTD_H 1
+#ifndef GRPC_CFSTREAM
+#define GPR_SUPPORT_CHANNELS_FROM_FD 1
+#endif
+#ifdef _LP64
+#define GPR_ARCH_64 1
+#else /* _LP64 */
+#define GPR_ARCH_32 1
+#endif /* _LP64 */
+#elif defined(__FreeBSD__)
+#define GPR_PLATFORM_STRING "freebsd"
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE
+#endif
+#define GPR_FREEBSD 1
+#define GPR_CPU_POSIX 1
+#define GPR_GCC_ATOMIC 1
+#define GPR_GCC_TLS 1
+#define GPR_POSIX_LOG 1
+#define GPR_POSIX_ENV 1
+#define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_SUBPROCESS 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_TIME 1
+#define GPR_HAS_PTHREAD_H 1
+#define GPR_GETPID_IN_UNISTD_H 1
+#define GPR_SUPPORT_CHANNELS_FROM_FD 1
+#ifdef _LP64
+#define GPR_ARCH_64 1
+#else /* _LP64 */
+#define GPR_ARCH_32 1
+#endif /* _LP64 */
+#elif defined(__OpenBSD__)
+#define GPR_PLATFORM_STRING "openbsd"
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE
+#endif
+#define GPR_OPENBSD 1
+#define GPR_CPU_POSIX 1
+#define GPR_GCC_ATOMIC 1
+#define GPR_GCC_TLS 1
+#define GPR_POSIX_LOG 1
+#define GPR_POSIX_ENV 1
+#define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_SUBPROCESS 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_TIME 1
+#define GPR_HAS_PTHREAD_H 1
+#define GPR_GETPID_IN_UNISTD_H 1
+#define GPR_SUPPORT_CHANNELS_FROM_FD 1
+#ifdef _LP64
+#define GPR_ARCH_64 1
+#else /* _LP64 */
+#define GPR_ARCH_32 1
+#endif /* _LP64 */
+#elif defined(__sun) && defined(__SVR4)
+#define GPR_PLATFORM_STRING "solaris"
+#define GPR_SOLARIS 1
+#define GPR_CPU_POSIX 1
+#define GPR_GCC_ATOMIC 1
+#define GPR_GCC_TLS 1
+#define GPR_POSIX_LOG 1
+#define GPR_POSIX_ENV 1
+#define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_SUBPROCESS 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_TIME 1
+#define GPR_HAS_PTHREAD_H 1
+#define GPR_GETPID_IN_UNISTD_H 1
+#ifdef _LP64
+#define GPR_ARCH_64 1
+#else /* _LP64 */
+#define GPR_ARCH_32 1
+#endif /* _LP64 */
+#elif defined(_AIX)
+#define GPR_PLATFORM_STRING "aix"
+#ifndef _ALL_SOURCE
+#define _ALL_SOURCE
+#endif
+#define GPR_AIX 1
+#define GPR_CPU_POSIX 1
+#define GPR_GCC_ATOMIC 1
+#define GPR_GCC_TLS 1
+#define GPR_POSIX_LOG 1
+#define GPR_POSIX_ENV 1
+#define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_SUBPROCESS 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_TIME 1
+#define GPR_HAS_PTHREAD_H 1
+#define GPR_GETPID_IN_UNISTD_H 1
+#ifdef _LP64
+#define GPR_ARCH_64 1
+#else /* _LP64 */
+#define GPR_ARCH_32 1
+#endif /* _LP64 */
+#elif defined(__native_client__)
+#define GPR_PLATFORM_STRING "nacl"
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE
+#endif
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE
+#endif
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#define GPR_NACL 1
+#define GPR_CPU_POSIX 1
+#define GPR_GCC_ATOMIC 1
+#define GPR_GCC_TLS 1
+#define GPR_POSIX_LOG 1
+#define GPR_POSIX_ENV 1
+#define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_SUBPROCESS 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_TIME 1
+#define GPR_HAS_PTHREAD_H 1
+#define GPR_GETPID_IN_UNISTD_H 1
+#ifdef _LP64
+#define GPR_ARCH_64 1
+#else /* _LP64 */
+#define GPR_ARCH_32 1
+#endif /* _LP64 */
+#elif defined(__Fuchsia__)
+#define GPR_FUCHSIA 1
+#define GPR_ARCH_64 1
+#define GPR_PLATFORM_STRING "fuchsia"
+#include <features.h>
+// Specifying musl libc affects wrap_memcpy.c. It causes memmove() to be
+// invoked.
+#define GPR_MUSL_LIBC_COMPAT 1
+#define GPR_CPU_POSIX 1
+#define GPR_GCC_ATOMIC 1
+#define GPR_PTHREAD_TLS 1
+#define GPR_POSIX_LOG 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_ENV 1
+#define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
+#define GPR_POSIX_SUBPROCESS 1
+#define GPR_POSIX_SYNC 1
+#define GPR_POSIX_STRING 1
+#define GPR_POSIX_TIME 1
+#define GPR_HAS_PTHREAD_H 1
+#define GPR_GETPID_IN_UNISTD_H 1
+#else
+#error "Could not auto-detect platform"
+#endif
+#endif /* GPR_NO_AUTODETECT_PLATFORM */
+
+#if defined(GPR_BACKWARDS_COMPATIBILITY_MODE)
+/*
+ * For backward compatibility mode, reset _FORTIFY_SOURCE to prevent
+ * a library from having non-standard symbols such as __asprintf_chk.
+ * This helps non-glibc systems such as alpine using musl to find symbols.
+ */
+#if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0
+#undef _FORTIFY_SOURCE
+#define _FORTIFY_SOURCE 0
+#endif
+#endif
+
+#if defined(__has_include)
+#if __has_include(<atomic>)
+#define GRPC_HAS_CXX11_ATOMIC
+#endif /* __has_include(<atomic>) */
+#endif /* defined(__has_include) */
+
+#ifndef GPR_PLATFORM_STRING
+#warning "GPR_PLATFORM_STRING not auto-detected"
+#define GPR_PLATFORM_STRING "unknown"
+#endif
+
+#ifdef GPR_GCOV
+#undef GPR_FORBID_UNREACHABLE_CODE
+#define GPR_FORBID_UNREACHABLE_CODE 1
+#endif
+
+#ifdef _MSC_VER
+#if _MSC_VER < 1700
+typedef __int8 int8_t;
+typedef __int16 int16_t;
+typedef __int32 int32_t;
+typedef __int64 int64_t;
+typedef unsigned __int8 uint8_t;
+typedef unsigned __int16 uint16_t;
+typedef unsigned __int32 uint32_t;
+typedef unsigned __int64 uint64_t;
+#else
+#include <stdint.h>
+#endif /* _MSC_VER < 1700 */
+#else
+#include <stdint.h>
+#endif /* _MSC_VER */
+
+/* Type of cycle clock implementation */
+#ifdef GPR_LINUX
+/* Disable cycle clock by default.
+   TODO(soheil): enable when we support fallback for unstable cycle clocks.
+#if defined(__i386__)
+#define GPR_CYCLE_COUNTER_RDTSC_32 1
+#elif defined(__x86_64__) || defined(__amd64__)
+#define GPR_CYCLE_COUNTER_RDTSC_64 1
+#else
+#define GPR_CYCLE_COUNTER_FALLBACK 1
+#endif
+*/
+#define GPR_CYCLE_COUNTER_FALLBACK 1
+#else
+#define GPR_CYCLE_COUNTER_FALLBACK 1
+#endif /* GPR_LINUX */
+
+/* Cache line alignment */
+#ifndef GPR_CACHELINE_SIZE_LOG
+#if defined(__i386__) || defined(__x86_64__)
+#define GPR_CACHELINE_SIZE_LOG 6
+#endif
+#ifndef GPR_CACHELINE_SIZE_LOG
+/* A reasonable default guess. Note that overestimates tend to waste more
+   space, while underestimates tend to waste more time. */
+#define GPR_CACHELINE_SIZE_LOG 6
+#endif /* GPR_CACHELINE_SIZE_LOG */
+#endif /* GPR_CACHELINE_SIZE_LOG */
+
+#define GPR_CACHELINE_SIZE (1 << GPR_CACHELINE_SIZE_LOG)
+
+/* scrub GCC_ATOMIC if it's not available on this compiler */
+#if defined(GPR_GCC_ATOMIC) && !defined(__ATOMIC_RELAXED)
+#undef GPR_GCC_ATOMIC
+#define GPR_GCC_SYNC 1
+#endif
+
+/* Validate platform combinations */
+#if defined(GPR_GCC_ATOMIC) + defined(GPR_GCC_SYNC) + \
+        defined(GPR_WINDOWS_ATOMIC) !=                \
+    1
+#error Must define exactly one of GPR_GCC_ATOMIC, GPR_GCC_SYNC, GPR_WINDOWS_ATOMIC
+#endif
+
+#if defined(GPR_ARCH_32) + defined(GPR_ARCH_64) != 1
+#error Must define exactly one of GPR_ARCH_32, GPR_ARCH_64
+#endif
+
+#if defined(GPR_CPU_LINUX) + defined(GPR_CPU_POSIX) + defined(GPR_WINDOWS) + \
+        defined(GPR_CPU_IPHONE) + defined(GPR_CPU_CUSTOM) !=                 \
+    1
+#error Must define exactly one of GPR_CPU_LINUX, GPR_CPU_POSIX, GPR_WINDOWS, GPR_CPU_IPHONE, GPR_CPU_CUSTOM
+#endif
+
+#if defined(GPR_MSVC_TLS) + defined(GPR_GCC_TLS) + defined(GPR_PTHREAD_TLS) + \
+        defined(GPR_STDCPP_TLS) + defined(GPR_CUSTOM_TLS) !=                  \
+    1
+#error Must define exactly one of GPR_MSVC_TLS, GPR_GCC_TLS, GPR_PTHREAD_TLS, GPR_STDCPP_TLS, GPR_CUSTOM_TLS
+#endif
+
+/* maximum alignment needed for any type on this platform, rounded up to a
+   power of two */
+#define GPR_MAX_ALIGNMENT 16
+
+#ifndef GRPC_ARES
+#define GRPC_ARES 1
+#endif
+
+#ifndef GRPC_IF_NAMETOINDEX
+#define GRPC_IF_NAMETOINDEX 1
+#endif
+
+#ifndef GRPC_MUST_USE_RESULT
+#if defined(__GNUC__) && !defined(__MINGW32__)
+#define GRPC_MUST_USE_RESULT __attribute__((warn_unused_result))
+#define GPR_ALIGN_STRUCT(n) __attribute__((aligned(n)))
+#else
+#define GRPC_MUST_USE_RESULT
+#define GPR_ALIGN_STRUCT(n)
+#endif
+#endif
+
+#ifndef GRPC_UNUSED
+#if defined(__GNUC__) && !defined(__MINGW32__)
+#define GRPC_UNUSED __attribute__((unused))
+#else
+#define GRPC_UNUSED
+#endif
+#endif
+
+#ifndef GPR_PRINT_FORMAT_CHECK
+#ifdef __GNUC__
+#define GPR_PRINT_FORMAT_CHECK(FORMAT_STR, ARGS) \
+  __attribute__((format(printf, FORMAT_STR, ARGS)))
+#else
+#define GPR_PRINT_FORMAT_CHECK(FORMAT_STR, ARGS)
+#endif
+#endif /* GPR_PRINT_FORMAT_CHECK */
+
+#if GPR_FORBID_UNREACHABLE_CODE
+#define GPR_UNREACHABLE_CODE(STATEMENT)
+#else
+#define GPR_UNREACHABLE_CODE(STATEMENT)             \
+  do {                                              \
+    gpr_log(GPR_ERROR, "Should never reach here."); \
+    abort();                                        \
+    STATEMENT;                                      \
+  } while (0)
+#endif /* GPR_FORBID_UNREACHABLE_CODE */
+
+#ifndef GPRAPI
+#define GPRAPI
+#endif
+
+#ifndef GRPCAPI
+#define GRPCAPI GPRAPI
+#endif
+
+#ifndef CENSUSAPI
+#define CENSUSAPI GRPCAPI
+#endif
+
+#ifndef GPR_HAS_ATTRIBUTE
+#ifdef __has_attribute
+#define GPR_HAS_ATTRIBUTE(a) __has_attribute(a)
+#else
+#define GPR_HAS_ATTRIBUTE(a) 0
+#endif
+#endif /* GPR_HAS_ATTRIBUTE */
+
+#ifndef GPR_HAS_FEATURE
+#ifdef __has_feature
+#define GPR_HAS_FEATURE(a) __has_feature(a)
+#else
+#define GPR_HAS_FEATURE(a) 0
+#endif
+#endif /* GPR_HAS_FEATURE */
+
+#ifndef GPR_ATTRIBUTE_NOINLINE
+#if GPR_HAS_ATTRIBUTE(noinline) || (defined(__GNUC__) && !defined(__clang__))
+#define GPR_ATTRIBUTE_NOINLINE __attribute__((noinline))
+#define GPR_HAS_ATTRIBUTE_NOINLINE 1
+#else
+#define GPR_ATTRIBUTE_NOINLINE
+#endif
+#endif /* GPR_ATTRIBUTE_NOINLINE */
+
+#ifndef GPR_ATTRIBUTE_WEAK
+/* Attribute weak is broken on LLVM/windows:
+ * https://bugs.llvm.org/show_bug.cgi?id=37598 */
+#if (GPR_HAS_ATTRIBUTE(weak) || (defined(__GNUC__) && !defined(__clang__))) && \
+    !(defined(__llvm__) && defined(_WIN32))
+#define GPR_ATTRIBUTE_WEAK __attribute__((weak))
+#define GPR_HAS_ATTRIBUTE_WEAK 1
+#else
+#define GPR_ATTRIBUTE_WEAK
+#endif
+#endif /* GPR_ATTRIBUTE_WEAK */
+
+#ifndef GPR_ATTRIBUTE_NO_TSAN /* (1) */
+#if GPR_HAS_FEATURE(thread_sanitizer)
+#define GPR_ATTRIBUTE_NO_TSAN __attribute__((no_sanitize("thread")))
+#endif                        /* GPR_HAS_FEATURE */
+#ifndef GPR_ATTRIBUTE_NO_TSAN /* (2) */
+#define GPR_ATTRIBUTE_NO_TSAN
+#endif /* GPR_ATTRIBUTE_NO_TSAN (2) */
+#endif /* GPR_ATTRIBUTE_NO_TSAN (1) */
+
+/* GRPC_TSAN_ENABLED will be defined, when compiled with thread sanitizer. */
+#ifndef GRPC_TSAN_SUPPRESSED
+#if defined(__SANITIZE_THREAD__)
+#define GRPC_TSAN_ENABLED
+#elif GPR_HAS_FEATURE(thread_sanitizer)
+#define GRPC_TSAN_ENABLED
+#endif
+#endif
+
+/* GRPC_ASAN_ENABLED will be defined, when compiled with address sanitizer. */
+#ifndef GRPC_ASAN_SUPPRESSED
+#if defined(__SANITIZE_ADDRESS__)
+#define GRPC_ASAN_ENABLED
+#elif GPR_HAS_FEATURE(address_sanitizer)
+#define GRPC_ASAN_ENABLED
+#endif
+#endif
+
+/* GRPC_ALLOW_EXCEPTIONS should be 0 or 1 if exceptions are allowed or not */
+#ifndef GRPC_ALLOW_EXCEPTIONS
+#ifdef GPR_WINDOWS
+#if defined(_MSC_VER) && defined(_CPPUNWIND)
+#define GRPC_ALLOW_EXCEPTIONS 1
+#elif defined(__EXCEPTIONS)
+#define GRPC_ALLOW_EXCEPTIONS 1
+#else
+#define GRPC_ALLOW_EXCEPTIONS 0
+#endif
+#else /* GPR_WINDOWS */
+#ifdef __EXCEPTIONS
+#define GRPC_ALLOW_EXCEPTIONS 1
+#else /* __EXCEPTIONS */
+#define GRPC_ALLOW_EXCEPTIONS 0
+#endif /* __EXCEPTIONS */
+#endif /* __GPR_WINDOWS */
+#endif /* GRPC_ALLOW_EXCEPTIONS */
+
+/* Use GPR_LIKELY only in cases where you are sure that a certain outcome is the
+ * most likely. Ideally, also collect performance numbers to justify the claim.
+ */
+#ifdef __GNUC__
+#define GPR_LIKELY(x) __builtin_expect((x), 1)
+#define GPR_UNLIKELY(x) __builtin_expect((x), 0)
+#else /* __GNUC__ */
+#define GPR_LIKELY(x) (x)
+#define GPR_UNLIKELY(x) (x)
+#endif /* __GNUC__ */
+
+#ifndef __STDC_FORMAT_MACROS
+#define __STDC_FORMAT_MACROS
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_PORT_PLATFORM_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/propagation_bits.h b/grpc/spm-core-include/grpc/impl/codegen/propagation_bits.h
new file mode 100644
index 00000000..824bdbd8
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/propagation_bits.h
@@ -0,0 +1,52 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_PROPAGATION_BITS_H
+#define GRPC_IMPL_CODEGEN_PROPAGATION_BITS_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Propagation bits: this can be bitwise or-ed to form propagation_mask for
+ * grpc_call */
+/** Propagate deadline */
+#define GRPC_PROPAGATE_DEADLINE ((uint32_t)1)
+/** Propagate census context */
+#define GRPC_PROPAGATE_CENSUS_STATS_CONTEXT ((uint32_t)2)
+#define GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT ((uint32_t)4)
+/** Propagate cancellation */
+#define GRPC_PROPAGATE_CANCELLATION ((uint32_t)8)
+
+/** Default propagation mask: clients of the core API are encouraged to encode
+   deltas from this in their implementations... ie write:
+   GRPC_PROPAGATE_DEFAULTS & ~GRPC_PROPAGATE_DEADLINE to disable deadline
+   propagation. Doing so gives flexibility in the future to define new
+   propagation types that are default inherited or not. */
+#define GRPC_PROPAGATE_DEFAULTS                                                \
+  ((uint32_t)((                                                                \
+      0xffff | GRPC_PROPAGATE_DEADLINE | GRPC_PROPAGATE_CENSUS_STATS_CONTEXT | \
+      GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT | GRPC_PROPAGATE_CANCELLATION)))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_PROPAGATION_BITS_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/slice.h b/grpc/spm-core-include/grpc/impl/codegen/slice.h
new file mode 100644
index 00000000..3567b1e8
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/slice.h
@@ -0,0 +1,127 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_SLICE_H
+#define GRPC_IMPL_CODEGEN_SLICE_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <stddef.h>
+
+#include <grpc/impl/codegen/gpr_slice.h>
+
+typedef struct grpc_slice grpc_slice;
+
+/** Slice API
+
+   A slice represents a contiguous reference counted array of bytes.
+   It is cheap to take references to a slice, and it is cheap to create a
+   slice pointing to a subset of another slice.
+
+   The data-structure for slices is exposed here to allow non-gpr code to
+   build slices from whatever data they have available.
+
+   When defining interfaces that handle slices, care should be taken to define
+   reference ownership semantics (who should call unref?) and mutability
+   constraints (is the callee allowed to modify the slice?) */
+
+/* Inlined half of grpc_slice is allowed to expand the size of the overall type
+   by this many bytes */
+#define GRPC_SLICE_INLINE_EXTRA_SIZE sizeof(void*)
+
+#define GRPC_SLICE_INLINED_SIZE \
+  (sizeof(size_t) + sizeof(uint8_t*) - 1 + GRPC_SLICE_INLINE_EXTRA_SIZE)
+
+struct grpc_slice_refcount;
+/** A grpc_slice s, if initialized, represents the byte range
+   s.bytes[0..s.length-1].
+
+   It can have an associated ref count which has a destruction routine to be run
+   when the ref count reaches zero (see grpc_slice_new() and grp_slice_unref()).
+   Multiple grpc_slice values may share a ref count.
+
+   If the slice does not have a refcount, it represents an inlined small piece
+   of data that is copied by value. */
+struct grpc_slice {
+  struct grpc_slice_refcount* refcount;
+  union grpc_slice_data {
+    struct grpc_slice_refcounted {
+      size_t length;
+      uint8_t* bytes;
+    } refcounted;
+    struct grpc_slice_inlined {
+      uint8_t length;
+      uint8_t bytes[GRPC_SLICE_INLINED_SIZE];
+    } inlined;
+  } data;
+};
+
+#define GRPC_SLICE_BUFFER_INLINE_ELEMENTS 8
+
+/** Represents an expandable array of slices, to be interpreted as a
+   single item. */
+typedef struct grpc_slice_buffer {
+  /** This is for internal use only. External users (i.e any code outside grpc
+   * core) MUST NOT use this field */
+  grpc_slice* base_slices;
+
+  /** slices in the array (Points to the first valid grpc_slice in the array) */
+  grpc_slice* slices;
+  /** the number of slices in the array */
+  size_t count;
+  /** the number of slices allocated in the array. External users (i.e any code
+   * outside grpc core) MUST NOT use this field */
+  size_t capacity;
+  /** the combined length of all slices in the array */
+  size_t length;
+  /** inlined elements to avoid allocations */
+  grpc_slice inlined[GRPC_SLICE_BUFFER_INLINE_ELEMENTS];
+} grpc_slice_buffer;
+
+#define GRPC_SLICE_START_PTR(slice)                 \
+  ((slice).refcount ? (slice).data.refcounted.bytes \
+                    : (slice).data.inlined.bytes)
+#define GRPC_SLICE_LENGTH(slice)                     \
+  ((slice).refcount ? (slice).data.refcounted.length \
+                    : (slice).data.inlined.length)
+#define GRPC_SLICE_SET_LENGTH(slice, newlen)                              \
+  ((slice).refcount ? ((slice).data.refcounted.length = (size_t)(newlen)) \
+                    : ((slice).data.inlined.length = (uint8_t)(newlen)))
+#define GRPC_SLICE_END_PTR(slice) \
+  GRPC_SLICE_START_PTR(slice) + GRPC_SLICE_LENGTH(slice)
+#define GRPC_SLICE_IS_EMPTY(slice) (GRPC_SLICE_LENGTH(slice) == 0)
+
+#ifdef GRPC_ALLOW_GPR_SLICE_FUNCTIONS
+
+/* Duplicate GPR_* definitions */
+#define GPR_SLICE_START_PTR(slice)                  \
+  ((slice).refcount ? (slice).data.refcounted.bytes \
+                    : (slice).data.inlined.bytes)
+#define GPR_SLICE_LENGTH(slice)                      \
+  ((slice).refcount ? (slice).data.refcounted.length \
+                    : (slice).data.inlined.length)
+#define GPR_SLICE_SET_LENGTH(slice, newlen)                               \
+  ((slice).refcount ? ((slice).data.refcounted.length = (size_t)(newlen)) \
+                    : ((slice).data.inlined.length = (uint8_t)(newlen)))
+#define GPR_SLICE_END_PTR(slice) \
+  GRPC_SLICE_START_PTR(slice) + GRPC_SLICE_LENGTH(slice)
+#define GPR_SLICE_IS_EMPTY(slice) (GRPC_SLICE_LENGTH(slice) == 0)
+
+#endif /* GRPC_ALLOW_GPR_SLICE_FUNCTIONS */
+
+#endif /* GRPC_IMPL_CODEGEN_SLICE_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/status.h b/grpc/spm-core-include/grpc/impl/codegen/status.h
new file mode 100644
index 00000000..dec3b8f3
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/status.h
@@ -0,0 +1,154 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_STATUS_H
+#define GRPC_IMPL_CODEGEN_STATUS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum {
+  /** Not an error; returned on success */
+  GRPC_STATUS_OK = 0,
+
+  /** The operation was cancelled (typically by the caller). */
+  GRPC_STATUS_CANCELLED = 1,
+
+  /** Unknown error.  An example of where this error may be returned is
+     if a Status value received from another address space belongs to
+     an error-space that is not known in this address space.  Also
+     errors raised by APIs that do not return enough error information
+     may be converted to this error. */
+  GRPC_STATUS_UNKNOWN = 2,
+
+  /** Client specified an invalid argument.  Note that this differs
+     from FAILED_PRECONDITION.  INVALID_ARGUMENT indicates arguments
+     that are problematic regardless of the state of the system
+     (e.g., a malformed file name). */
+  GRPC_STATUS_INVALID_ARGUMENT = 3,
+
+  /** Deadline expired before operation could complete.  For operations
+     that change the state of the system, this error may be returned
+     even if the operation has completed successfully.  For example, a
+     successful response from a server could have been delayed long
+     enough for the deadline to expire. */
+  GRPC_STATUS_DEADLINE_EXCEEDED = 4,
+
+  /** Some requested entity (e.g., file or directory) was not found. */
+  GRPC_STATUS_NOT_FOUND = 5,
+
+  /** Some entity that we attempted to create (e.g., file or directory)
+     already exists. */
+  GRPC_STATUS_ALREADY_EXISTS = 6,
+
+  /** The caller does not have permission to execute the specified
+     operation.  PERMISSION_DENIED must not be used for rejections
+     caused by exhausting some resource (use RESOURCE_EXHAUSTED
+     instead for those errors).  PERMISSION_DENIED must not be
+     used if the caller can not be identified (use UNAUTHENTICATED
+     instead for those errors). */
+  GRPC_STATUS_PERMISSION_DENIED = 7,
+
+  /** The request does not have valid authentication credentials for the
+     operation. */
+  GRPC_STATUS_UNAUTHENTICATED = 16,
+
+  /** Some resource has been exhausted, perhaps a per-user quota, or
+     perhaps the entire file system is out of space. */
+  GRPC_STATUS_RESOURCE_EXHAUSTED = 8,
+
+  /** Operation was rejected because the system is not in a state
+     required for the operation's execution.  For example, directory
+     to be deleted may be non-empty, an rmdir operation is applied to
+     a non-directory, etc.
+
+     A litmus test that may help a service implementor in deciding
+     between FAILED_PRECONDITION, ABORTED, and UNAVAILABLE:
+      (a) Use UNAVAILABLE if the client can retry just the failing call.
+      (b) Use ABORTED if the client should retry at a higher-level
+          (e.g., restarting a read-modify-write sequence).
+      (c) Use FAILED_PRECONDITION if the client should not retry until
+          the system state has been explicitly fixed.  E.g., if an "rmdir"
+          fails because the directory is non-empty, FAILED_PRECONDITION
+          should be returned since the client should not retry unless
+          they have first fixed up the directory by deleting files from it.
+      (d) Use FAILED_PRECONDITION if the client performs conditional
+          REST Get/Update/Delete on a resource and the resource on the
+          server does not match the condition. E.g., conflicting
+          read-modify-write on the same resource. */
+  GRPC_STATUS_FAILED_PRECONDITION = 9,
+
+  /** The operation was aborted, typically due to a concurrency issue
+     like sequencer check failures, transaction aborts, etc.
+
+     See litmus test above for deciding between FAILED_PRECONDITION,
+     ABORTED, and UNAVAILABLE. */
+  GRPC_STATUS_ABORTED = 10,
+
+  /** Operation was attempted past the valid range.  E.g., seeking or
+     reading past end of file.
+
+     Unlike INVALID_ARGUMENT, this error indicates a problem that may
+     be fixed if the system state changes. For example, a 32-bit file
+     system will generate INVALID_ARGUMENT if asked to read at an
+     offset that is not in the range [0,2^32-1], but it will generate
+     OUT_OF_RANGE if asked to read from an offset past the current
+     file size.
+
+     There is a fair bit of overlap between FAILED_PRECONDITION and
+     OUT_OF_RANGE.  We recommend using OUT_OF_RANGE (the more specific
+     error) when it applies so that callers who are iterating through
+     a space can easily look for an OUT_OF_RANGE error to detect when
+     they are done. */
+  GRPC_STATUS_OUT_OF_RANGE = 11,
+
+  /** Operation is not implemented or not supported/enabled in this service. */
+  GRPC_STATUS_UNIMPLEMENTED = 12,
+
+  /** Internal errors.  Means some invariants expected by underlying
+     system has been broken.  If you see one of these errors,
+     something is very broken. */
+  GRPC_STATUS_INTERNAL = 13,
+
+  /** The service is currently unavailable.  This is a most likely a
+     transient condition and may be corrected by retrying with
+     a backoff. Note that it is not always safe to retry non-idempotent
+     operations.
+
+     WARNING: Although data MIGHT not have been transmitted when this
+     status occurs, there is NOT A GUARANTEE that the server has not seen
+     anything. So in general it is unsafe to retry on this status code
+     if the call is non-idempotent.
+
+     See litmus test above for deciding between FAILED_PRECONDITION,
+     ABORTED, and UNAVAILABLE. */
+  GRPC_STATUS_UNAVAILABLE = 14,
+
+  /** Unrecoverable data loss or corruption. */
+  GRPC_STATUS_DATA_LOSS = 15,
+
+  /** Force users to include a default branch: */
+  GRPC_STATUS__DO_NOT_USE = -1
+} grpc_status_code;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_STATUS_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/sync.h b/grpc/spm-core-include/grpc/impl/codegen/sync.h
new file mode 100644
index 00000000..49e31947
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/sync.h
@@ -0,0 +1,65 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_SYNC_H
+#define GRPC_IMPL_CODEGEN_SYNC_H
+/** Synchronization primitives for GPR.
+
+   The type  gpr_mu              provides a non-reentrant mutex (lock).
+
+   The type  gpr_cv              provides a condition variable.
+
+   The type  gpr_once            provides for one-time initialization.
+
+   The type gpr_event            provides one-time-setting, reading, and
+                                 waiting of a void*, with memory barriers.
+
+   The type gpr_refcount         provides an object reference counter,
+                                 with memory barriers suitable to control
+                                 object lifetimes.
+
+   The type gpr_stats_counter    provides an atomic statistics counter. It
+                                 provides no memory barriers.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Platform-specific type declarations of gpr_mu and gpr_cv.   */
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <grpc/impl/codegen/sync_generic.h>
+
+#if defined(GPR_CUSTOM_SYNC)
+#include <grpc/impl/codegen/sync_custom.h>
+#elif defined(GPR_ABSEIL_SYNC)
+#include <grpc/impl/codegen/sync_abseil.h>
+#elif defined(GPR_POSIX_SYNC)
+#include <grpc/impl/codegen/sync_posix.h>
+#elif defined(GPR_WINDOWS)
+#include <grpc/impl/codegen/sync_windows.h>
+#else
+#error Unable to determine platform for sync
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_SYNC_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/sync_abseil.h b/grpc/spm-core-include/grpc/impl/codegen/sync_abseil.h
new file mode 100644
index 00000000..38dfab32
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/sync_abseil.h
@@ -0,0 +1,36 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_SYNC_ABSEIL_H
+#define GRPC_IMPL_CODEGEN_SYNC_ABSEIL_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <grpc/impl/codegen/sync_generic.h>
+
+#ifdef GPR_ABSEIL_SYNC
+
+typedef intptr_t gpr_mu;
+typedef intptr_t gpr_cv;
+typedef int32_t gpr_once;
+
+#define GPR_ONCE_INIT 0
+
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_SYNC_ABSEIL_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/sync_custom.h b/grpc/spm-core-include/grpc/impl/codegen/sync_custom.h
new file mode 100644
index 00000000..69b1bf6c
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/sync_custom.h
@@ -0,0 +1,38 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_SYNC_CUSTOM_H
+#define GRPC_IMPL_CODEGEN_SYNC_CUSTOM_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <grpc/impl/codegen/sync_generic.h>
+
+/* Users defining GPR_CUSTOM_SYNC need to define the following macros. */
+
+#ifdef GPR_CUSTOM_SYNC
+
+typedef GPR_CUSTOM_MU_TYPE gpr_mu;
+typedef GPR_CUSTOM_CV_TYPE gpr_cv;
+typedef GPR_CUSTOM_ONCE_TYPE gpr_once;
+
+#define GPR_ONCE_INIT GPR_CUSTOM_ONCE_INIT
+
+#endif
+
+#endif /* GRPC_IMPL_CODEGEN_SYNC_CUSTOM_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/sync_generic.h b/grpc/spm-core-include/grpc/impl/codegen/sync_generic.h
new file mode 100644
index 00000000..eabdc513
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/sync_generic.h
@@ -0,0 +1,48 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_SYNC_GENERIC_H
+#define GRPC_IMPL_CODEGEN_SYNC_GENERIC_H
+/* Generic type definitions for gpr_sync. */
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <grpc/impl/codegen/atm.h>
+
+/* gpr_event */
+typedef struct {
+  gpr_atm state;
+} gpr_event;
+
+#define GPR_EVENT_INIT \
+  { 0 }
+
+/* gpr_refcount */
+typedef struct {
+  gpr_atm count;
+} gpr_refcount;
+
+/* gpr_stats_counter */
+typedef struct {
+  gpr_atm value;
+} gpr_stats_counter;
+
+#define GPR_STATS_INIT \
+  { 0 }
+
+#endif /* GRPC_IMPL_CODEGEN_SYNC_GENERIC_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/sync_posix.h b/grpc/spm-core-include/grpc/impl/codegen/sync_posix.h
new file mode 100644
index 00000000..2aec3a3f
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/sync_posix.h
@@ -0,0 +1,52 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_SYNC_POSIX_H
+#define GRPC_IMPL_CODEGEN_SYNC_POSIX_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#include <grpc/impl/codegen/sync_generic.h>
+
+#include <pthread.h>
+
+#ifdef GRPC_ASAN_ENABLED
+/* The member |leak_checker| is used to check whether there is a memory leak
+ * caused by upper layer logic that's missing the |gpr_xx_destroy| call
+ * to the object before freeing it.
+ * This issue was reported at https://github.com/grpc/grpc/issues/17563
+ * and discussed at https://github.com/grpc/grpc/pull/17586
+ */
+typedef struct {
+  pthread_mutex_t mutex;
+  int* leak_checker;
+} gpr_mu;
+
+typedef struct {
+  pthread_cond_t cond_var;
+  int* leak_checker;
+} gpr_cv;
+#else
+typedef pthread_mutex_t gpr_mu;
+typedef pthread_cond_t gpr_cv;
+#endif
+typedef pthread_once_t gpr_once;
+
+#define GPR_ONCE_INIT PTHREAD_ONCE_INIT
+
+#endif /* GRPC_IMPL_CODEGEN_SYNC_POSIX_H */
diff --git a/grpc/spm-core-include/grpc/impl/codegen/sync_windows.h b/grpc/spm-core-include/grpc/impl/codegen/sync_windows.h
new file mode 100644
index 00000000..f2ff83b3
--- /dev/null
+++ b/grpc/spm-core-include/grpc/impl/codegen/sync_windows.h
@@ -0,0 +1,40 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_IMPL_CODEGEN_SYNC_WINDOWS_H
+#define GRPC_IMPL_CODEGEN_SYNC_WINDOWS_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#ifdef GPR_WINDOWS
+
+#include <grpc/impl/codegen/sync_generic.h>
+
+typedef struct {
+  CRITICAL_SECTION cs; /* Not an SRWLock until Vista is unsupported */
+  int locked;
+} gpr_mu;
+
+typedef CONDITION_VARIABLE gpr_cv;
+
+typedef INIT_ONCE gpr_once;
+#define GPR_ONCE_INIT INIT_ONCE_STATIC_INIT
+
+#endif /* GPR_WINDOWS */
+
+#endif /* GRPC_IMPL_CODEGEN_SYNC_WINDOWS_H */
diff --git a/grpc/spm-core-include/grpc/load_reporting.h b/grpc/spm-core-include/grpc/load_reporting.h
new file mode 100644
index 00000000..55f50ea8
--- /dev/null
+++ b/grpc/spm-core-include/grpc/load_reporting.h
@@ -0,0 +1,48 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_LOAD_REPORTING_H
+#define GRPC_LOAD_REPORTING_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Metadata key for the gRPC LB load balancer token.
+ *
+ * The value corresponding to this key is an opaque token that is given to the
+ * frontend as part of each pick; the frontend sends this token to the backend
+ * in each request it sends when using that pick. The token is used by the
+ * backend to verify the request and to allow the backend to report load to the
+ * gRPC LB system. */
+#define GRPC_LB_TOKEN_MD_KEY "lb-token"
+
+/** Metadata key for gRPC LB cost reporting.
+ *
+ * The value corresponding to this key is an opaque binary blob reported by the
+ * backend as part of its trailing metadata containing cost information for the
+ * call. */
+#define GRPC_LB_COST_MD_KEY "lb-cost-bin"
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_LOAD_REPORTING_H */
diff --git a/grpc/spm-core-include/grpc/module.modulemap b/grpc/spm-core-include/grpc/module.modulemap
new file mode 100644
index 00000000..06c1e977
--- /dev/null
+++ b/grpc/spm-core-include/grpc/module.modulemap
@@ -0,0 +1,64 @@
+
+framework module grpc {
+  umbrella header "grpc.h"
+
+  header "impl/codegen/atm.h"
+  header "impl/codegen/byte_buffer.h"
+  header "impl/codegen/byte_buffer_reader.h"
+  header "impl/codegen/compression_types.h"
+  header "impl/codegen/connectivity_state.h"
+  header "impl/codegen/fork.h"
+  header "impl/codegen/gpr_slice.h"
+  header "impl/codegen/gpr_types.h"
+  header "impl/codegen/grpc_types.h"
+  header "impl/codegen/log.h"
+  header "impl/codegen/port_platform.h"
+  header "impl/codegen/propagation_bits.h"
+  header "impl/codegen/slice.h"
+  header "impl/codegen/status.h"
+  header "impl/codegen/sync.h"
+  header "impl/codegen/sync_abseil.h"
+  header "impl/codegen/sync_generic.h"
+  header "support/alloc.h"
+  header "support/atm.h"
+  header "support/cpu.h"
+  header "support/log.h"
+  header "support/log_windows.h"
+  header "support/port_platform.h"
+  header "support/string_util.h"
+  header "support/sync.h"
+  header "support/sync_abseil.h"
+  header "support/sync_generic.h"
+  header "support/thd_id.h"
+  header "support/time.h"
+  header "byte_buffer.h"
+  header "byte_buffer_reader.h"
+  header "census.h"
+  header "compression.h"
+  header "fork.h"
+  header "grpc.h"
+  header "grpc_posix.h"
+  header "grpc_security.h"
+  header "grpc_security_constants.h"
+  header "load_reporting.h"
+  header "slice.h"
+  header "slice_buffer.h"
+  header "status.h"
+  header "support/workaround_list.h"
+
+  textual header "impl/codegen/atm_gcc_atomic.h"
+  textual header "impl/codegen/atm_gcc_sync.h"
+  textual header "impl/codegen/atm_windows.h"
+  textual header "impl/codegen/sync_custom.h"
+  textual header "impl/codegen/sync_posix.h"
+  textual header "impl/codegen/sync_windows.h"
+  textual header "support/atm_gcc_atomic.h"
+  textual header "support/atm_gcc_sync.h"
+  textual header "support/atm_windows.h"
+  textual header "support/sync_custom.h"
+  textual header "support/sync_posix.h"
+  textual header "support/sync_windows.h"
+
+  export *
+  module * { export * }
+}
diff --git a/grpc/spm-core-include/grpc/slice.h b/grpc/spm-core-include/grpc/slice.h
new file mode 100644
index 00000000..51fc62b4
--- /dev/null
+++ b/grpc/spm-core-include/grpc/slice.h
@@ -0,0 +1,172 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SLICE_H
+#define GRPC_SLICE_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/slice.h>
+#include <grpc/support/sync.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Increment the refcount of s. Requires slice is initialized.
+   Returns s. */
+GPRAPI grpc_slice grpc_slice_ref(grpc_slice s);
+
+/** Decrement the ref count of s.  If the ref count of s reaches zero, all
+   slices sharing the ref count are destroyed, and considered no longer
+   initialized.  If s is ultimately derived from a call to grpc_slice_new(start,
+   len, dest) where dest!=NULL , then (*dest)(start) is called, else if s is
+   ultimately derived from a call to grpc_slice_new_with_len(start, len, dest)
+   where dest!=NULL , then (*dest)(start, len).  Requires s initialized.  */
+GPRAPI void grpc_slice_unref(grpc_slice s);
+
+/** Copy slice - create a new slice that contains the same data as s */
+GPRAPI grpc_slice grpc_slice_copy(grpc_slice s);
+
+/** Create a slice pointing at some data. Calls malloc to allocate a refcount
+   for the object, and arranges that destroy will be called with the pointer
+   passed in at destruction. */
+GPRAPI grpc_slice grpc_slice_new(void* p, size_t len, void (*destroy)(void*));
+
+/** Equivalent to grpc_slice_new, but with a separate pointer that is
+   passed to the destroy function.  This function can be useful when
+   the data is part of a larger structure that must be destroyed when
+   the data is no longer needed. */
+GPRAPI grpc_slice grpc_slice_new_with_user_data(void* p, size_t len,
+                                                void (*destroy)(void*),
+                                                void* user_data);
+
+/** Equivalent to grpc_slice_new, but with a two argument destroy function that
+   also takes the slice length. */
+GPRAPI grpc_slice grpc_slice_new_with_len(void* p, size_t len,
+                                          void (*destroy)(void*, size_t));
+
+/** Equivalent to grpc_slice_new(malloc(len), len, free), but saves one malloc()
+   call.
+   Aborts if malloc() fails. */
+GPRAPI grpc_slice grpc_slice_malloc(size_t length);
+GPRAPI grpc_slice grpc_slice_malloc_large(size_t length);
+
+#define GRPC_SLICE_MALLOC(len) grpc_slice_malloc(len)
+
+/** Intern a slice:
+
+   The return value for two invocations of this function with  the same sequence
+   of bytes is a slice which points to the same memory. */
+GPRAPI grpc_slice grpc_slice_intern(grpc_slice slice);
+
+/** Create a slice by copying a string.
+   Does not preserve null terminators.
+   Equivalent to:
+     size_t len = strlen(source);
+     grpc_slice slice = grpc_slice_malloc(len);
+     memcpy(slice->data, source, len); */
+GPRAPI grpc_slice grpc_slice_from_copied_string(const char* source);
+
+/** Create a slice by copying a buffer.
+   Equivalent to:
+     grpc_slice slice = grpc_slice_malloc(len);
+     memcpy(slice->data, source, len); */
+GPRAPI grpc_slice grpc_slice_from_copied_buffer(const char* source, size_t len);
+
+/** Create a slice pointing to constant memory */
+GPRAPI grpc_slice grpc_slice_from_static_string(const char* source);
+
+/** Create a slice pointing to constant memory */
+GPRAPI grpc_slice grpc_slice_from_static_buffer(const void* source, size_t len);
+
+/** Return a result slice derived from s, which shares a ref count with \a s,
+   where result.data==s.data+begin, and result.length==end-begin. The ref count
+   of \a s is increased by one. Do not assign result back to \a s.
+   Requires s initialized, begin <= end, begin <= s.length, and
+   end <= source->length. */
+GPRAPI grpc_slice grpc_slice_sub(grpc_slice s, size_t begin, size_t end);
+
+/** The same as grpc_slice_sub, but without altering the ref count */
+GPRAPI grpc_slice grpc_slice_sub_no_ref(grpc_slice s, size_t begin, size_t end);
+
+/** Splits s into two: modifies s to be s[0:split], and returns a new slice,
+   sharing a refcount with s, that contains s[split:s.length].
+   Requires s initialized, split <= s.length */
+GPRAPI grpc_slice grpc_slice_split_tail(grpc_slice* s, size_t split);
+
+typedef enum {
+  GRPC_SLICE_REF_TAIL = 1,
+  GRPC_SLICE_REF_HEAD = 2,
+  GRPC_SLICE_REF_BOTH = 1 + 2
+} grpc_slice_ref_whom;
+
+/** The same as grpc_slice_split_tail, but with an option to skip altering
+ * refcounts (grpc_slice_split_tail_maybe_ref(..., true) is equivalent to
+ * grpc_slice_split_tail(...)) */
+GPRAPI grpc_slice grpc_slice_split_tail_maybe_ref(grpc_slice* s, size_t split,
+                                                  grpc_slice_ref_whom ref_whom);
+
+/** Splits s into two: modifies s to be s[split:s.length], and returns a new
+   slice, sharing a refcount with s, that contains s[0:split].
+   Requires s initialized, split <= s.length */
+GPRAPI grpc_slice grpc_slice_split_head(grpc_slice* s, size_t split);
+
+GPRAPI grpc_slice grpc_empty_slice(void);
+
+GPRAPI uint32_t grpc_slice_default_hash_impl(grpc_slice s);
+GPRAPI int grpc_slice_default_eq_impl(grpc_slice a, grpc_slice b);
+
+GPRAPI int grpc_slice_eq(grpc_slice a, grpc_slice b);
+
+/** Returns <0 if a < b, ==0 if a == b, >0 if a > b
+   The order is arbitrary, and is not guaranteed to be stable across different
+   versions of the API. */
+GPRAPI int grpc_slice_cmp(grpc_slice a, grpc_slice b);
+GPRAPI int grpc_slice_str_cmp(grpc_slice a, const char* b);
+
+/** return non-zero if the first blen bytes of a are equal to b */
+GPRAPI int grpc_slice_buf_start_eq(grpc_slice a, const void* b, size_t blen);
+
+/** return the index of the last instance of \a c in \a s, or -1 if not found */
+GPRAPI int grpc_slice_rchr(grpc_slice s, char c);
+GPRAPI int grpc_slice_chr(grpc_slice s, char c);
+
+/** return the index of the first occurrence of \a needle in \a haystack, or -1
+   if it's not found */
+GPRAPI int grpc_slice_slice(grpc_slice haystack, grpc_slice needle);
+
+GPRAPI uint32_t grpc_slice_hash(grpc_slice s);
+
+/** Do two slices point at the same memory, with the same length
+   If a or b is inlined, actually compares data */
+GPRAPI int grpc_slice_is_equivalent(grpc_slice a, grpc_slice b);
+
+/** Return a slice pointing to newly allocated memory that has the same contents
+ * as \a s */
+GPRAPI grpc_slice grpc_slice_dup(grpc_slice a);
+
+/** Return a copy of slice as a C string. Offers no protection against embedded
+   NULL's. Returned string must be freed with gpr_free. */
+GPRAPI char* grpc_slice_to_c_string(grpc_slice s);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_SLICE_H */
diff --git a/grpc/spm-core-include/grpc/slice_buffer.h b/grpc/spm-core-include/grpc/slice_buffer.h
new file mode 100644
index 00000000..d8c6b918
--- /dev/null
+++ b/grpc/spm-core-include/grpc/slice_buffer.h
@@ -0,0 +1,84 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SLICE_BUFFER_H
+#define GRPC_SLICE_BUFFER_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/slice.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** initialize a slice buffer */
+GPRAPI void grpc_slice_buffer_init(grpc_slice_buffer* sb);
+/** destroy a slice buffer - unrefs any held elements */
+GPRAPI void grpc_slice_buffer_destroy(grpc_slice_buffer* sb);
+/** Add an element to a slice buffer - takes ownership of the slice.
+   This function is allowed to concatenate the passed in slice to the end of
+   some other slice if desired by the slice buffer. */
+GPRAPI void grpc_slice_buffer_add(grpc_slice_buffer* sb, grpc_slice slice);
+/** add an element to a slice buffer - takes ownership of the slice and returns
+   the index of the slice.
+   Guarantees that the slice will not be concatenated at the end of another
+   slice (i.e. the data for this slice will begin at the first byte of the
+   slice at the returned index in sb->slices)
+   The implementation MAY decide to concatenate data at the end of a small
+   slice added in this fashion. */
+GPRAPI size_t grpc_slice_buffer_add_indexed(grpc_slice_buffer* sb,
+                                            grpc_slice slice);
+GPRAPI void grpc_slice_buffer_addn(grpc_slice_buffer* sb, grpc_slice* slices,
+                                   size_t n);
+/** add a very small (less than 8 bytes) amount of data to the end of a slice
+   buffer: returns a pointer into which to add the data */
+GPRAPI uint8_t* grpc_slice_buffer_tiny_add(grpc_slice_buffer* sb, size_t len);
+/** pop the last buffer, but don't unref it */
+GPRAPI void grpc_slice_buffer_pop(grpc_slice_buffer* sb);
+/** clear a slice buffer, unref all elements */
+GPRAPI void grpc_slice_buffer_reset_and_unref(grpc_slice_buffer* sb);
+/** swap the contents of two slice buffers */
+GPRAPI void grpc_slice_buffer_swap(grpc_slice_buffer* a, grpc_slice_buffer* b);
+/** move all of the elements of src into dst */
+GPRAPI void grpc_slice_buffer_move_into(grpc_slice_buffer* src,
+                                        grpc_slice_buffer* dst);
+/** remove n bytes from the end of a slice buffer */
+GPRAPI void grpc_slice_buffer_trim_end(grpc_slice_buffer* sb, size_t n,
+                                       grpc_slice_buffer* garbage);
+/** move the first n bytes of src into dst */
+GPRAPI void grpc_slice_buffer_move_first(grpc_slice_buffer* src, size_t n,
+                                         grpc_slice_buffer* dst);
+/** move the first n bytes of src into dst without adding references */
+GPRAPI void grpc_slice_buffer_move_first_no_ref(grpc_slice_buffer* src,
+                                                size_t n,
+                                                grpc_slice_buffer* dst);
+/** move the first n bytes of src into dst (copying them) */
+GPRAPI void grpc_slice_buffer_move_first_into_buffer(grpc_slice_buffer* src,
+                                                     size_t n, void* dst);
+/** take the first slice in the slice buffer */
+GPRAPI grpc_slice grpc_slice_buffer_take_first(grpc_slice_buffer* sb);
+/** undo the above with (a possibly different) \a slice */
+GPRAPI void grpc_slice_buffer_undo_take_first(grpc_slice_buffer* sb,
+                                              grpc_slice slice);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_SLICE_BUFFER_H */
diff --git a/grpc/spm-core-include/grpc/status.h b/grpc/spm-core-include/grpc/status.h
new file mode 100644
index 00000000..ecb9668b
--- /dev/null
+++ b/grpc/spm-core-include/grpc/status.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_STATUS_H
+#define GRPC_STATUS_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/status.h>
+
+#endif /* GRPC_STATUS_H */
diff --git a/grpc/spm-core-include/grpc/support/alloc.h b/grpc/spm-core-include/grpc/support/alloc.h
new file mode 100644
index 00000000..d440e4be
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/alloc.h
@@ -0,0 +1,52 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_ALLOC_H
+#define GRPC_SUPPORT_ALLOC_H
+
+#include <grpc/support/port_platform.h>
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** malloc.
+ * If size==0, always returns NULL. Otherwise this function never returns NULL.
+ * The pointer returned is suitably aligned for any kind of variable it could
+ * contain.
+ */
+GPRAPI void* gpr_malloc(size_t size);
+/** like malloc, but zero all bytes before returning them */
+GPRAPI void* gpr_zalloc(size_t size);
+/** free */
+GPRAPI void gpr_free(void* ptr);
+/** realloc, never returns NULL */
+GPRAPI void* gpr_realloc(void* p, size_t size);
+/** aligned malloc, never returns NULL, will align to alignment, which
+ * must be a power of 2. */
+GPRAPI void* gpr_malloc_aligned(size_t size, size_t alignment);
+/** free memory allocated by gpr_malloc_aligned */
+GPRAPI void gpr_free_aligned(void* ptr);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_SUPPORT_ALLOC_H */
diff --git a/grpc/spm-core-include/grpc/support/atm.h b/grpc/spm-core-include/grpc/support/atm.h
new file mode 100644
index 00000000..073b0a6f
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/atm.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_ATM_H
+#define GRPC_SUPPORT_ATM_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/atm.h>
+
+#endif /* GRPC_SUPPORT_ATM_H */
diff --git a/grpc/spm-core-include/grpc/support/atm_gcc_atomic.h b/grpc/spm-core-include/grpc/support/atm_gcc_atomic.h
new file mode 100644
index 00000000..ae603db4
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/atm_gcc_atomic.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_ATM_GCC_ATOMIC_H
+#define GRPC_SUPPORT_ATM_GCC_ATOMIC_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/atm_gcc_atomic.h>
+
+#endif /* GRPC_SUPPORT_ATM_GCC_ATOMIC_H */
diff --git a/grpc/spm-core-include/grpc/support/atm_gcc_sync.h b/grpc/spm-core-include/grpc/support/atm_gcc_sync.h
new file mode 100644
index 00000000..6f51fdb1
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/atm_gcc_sync.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_ATM_GCC_SYNC_H
+#define GRPC_SUPPORT_ATM_GCC_SYNC_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/atm_gcc_sync.h>
+
+#endif /* GRPC_SUPPORT_ATM_GCC_SYNC_H */
diff --git a/grpc/spm-core-include/grpc/support/atm_windows.h b/grpc/spm-core-include/grpc/support/atm_windows.h
new file mode 100644
index 00000000..36955e4d
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/atm_windows.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_ATM_WINDOWS_H
+#define GRPC_SUPPORT_ATM_WINDOWS_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/atm_windows.h>
+
+#endif /* GRPC_SUPPORT_ATM_WINDOWS_H */
diff --git a/grpc/spm-core-include/grpc/support/cpu.h b/grpc/spm-core-include/grpc/support/cpu.h
new file mode 100644
index 00000000..f0e898e8
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/cpu.h
@@ -0,0 +1,44 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_CPU_H
+#define GRPC_SUPPORT_CPU_H
+
+#include <grpc/support/port_platform.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Interface providing CPU information for currently running system */
+
+/** Return the number of CPU cores on the current system. Will return 0 if
+   the information is not available. */
+GPRAPI unsigned gpr_cpu_num_cores(void);
+
+/** Return the CPU on which the current thread is executing; N.B. This should
+   be considered advisory only - it is possible that the thread is switched
+   to a different CPU at any time. Returns a value in range
+   [0, gpr_cpu_num_cores() - 1] */
+GPRAPI unsigned gpr_cpu_current_cpu(void);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif /* GRPC_SUPPORT_CPU_H */
diff --git a/grpc/spm-core-include/grpc/support/log.h b/grpc/spm-core-include/grpc/support/log.h
new file mode 100644
index 00000000..8d8742b9
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/log.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_LOG_H
+#define GRPC_SUPPORT_LOG_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/log.h>
+
+#endif /* GRPC_SUPPORT_LOG_H */
diff --git a/grpc/spm-core-include/grpc/support/log_windows.h b/grpc/spm-core-include/grpc/support/log_windows.h
new file mode 100644
index 00000000..e833f9d9
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/log_windows.h
@@ -0,0 +1,38 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_LOG_WINDOWS_H
+#define GRPC_SUPPORT_LOG_WINDOWS_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Returns a string allocated with gpr_malloc that contains a UTF-8
+ * formatted error message, corresponding to the error messageid.
+ * Use in conjunction with GetLastError() et al.
+ */
+GPRAPI char* gpr_format_message(int messageid);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_SUPPORT_LOG_WINDOWS_H */
diff --git a/grpc/spm-core-include/grpc/support/port_platform.h b/grpc/spm-core-include/grpc/support/port_platform.h
new file mode 100644
index 00000000..26025dcd
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/port_platform.h
@@ -0,0 +1,24 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_PORT_PLATFORM_H
+#define GRPC_SUPPORT_PORT_PLATFORM_H
+
+#include <grpc/impl/codegen/port_platform.h>
+
+#endif /* GRPC_SUPPORT_PORT_PLATFORM_H */
diff --git a/grpc/spm-core-include/grpc/support/string_util.h b/grpc/spm-core-include/grpc/support/string_util.h
new file mode 100644
index 00000000..2679160c
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/string_util.h
@@ -0,0 +1,51 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_STRING_UTIL_H
+#define GRPC_SUPPORT_STRING_UTIL_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/gpr_types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** String utility functions */
+
+/** Returns a copy of src that can be passed to gpr_free().
+   If allocation fails or if src is NULL, returns NULL. */
+GPRAPI char* gpr_strdup(const char* src);
+
+/** printf to a newly-allocated string.  The set of supported formats may vary
+   between platforms.
+
+   On success, returns the number of bytes printed (excluding the final '\0'),
+   and *strp points to a string which must later be destroyed with gpr_free().
+
+   On error, returns -1 and sets *strp to NULL. If the format string is bad,
+   the result is undefined. */
+GPRAPI int gpr_asprintf(char** strp, const char* format, ...)
+    GPR_PRINT_FORMAT_CHECK(2, 3);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_SUPPORT_STRING_UTIL_H */
diff --git a/grpc/spm-core-include/grpc/support/sync.h b/grpc/spm-core-include/grpc/support/sync.h
new file mode 100644
index 00000000..f617322f
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/sync.h
@@ -0,0 +1,282 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_SYNC_H
+#define GRPC_SUPPORT_SYNC_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/gpr_types.h> /* for gpr_timespec */
+#include <grpc/impl/codegen/sync.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** --- Mutex interface ---
+
+   At most one thread may hold an exclusive lock on a mutex at any given time.
+   Actions taken by a thread that holds a mutex exclusively happen after
+   actions taken by all previous holders of the mutex.  Variables of type
+   gpr_mu are uninitialized when first declared.  */
+
+/** Initialize *mu.  Requires:  *mu uninitialized.  */
+GPRAPI void gpr_mu_init(gpr_mu* mu);
+
+/** Cause *mu no longer to be initialized, freeing any memory in use.  Requires:
+ *mu initialized; no other concurrent operation on *mu.  */
+GPRAPI void gpr_mu_destroy(gpr_mu* mu);
+
+/** Wait until no thread has a lock on *mu, cause the calling thread to own an
+   exclusive lock on *mu, then return.  May block indefinitely or crash if the
+   calling thread has a lock on *mu.  Requires:  *mu initialized.  */
+GPRAPI void gpr_mu_lock(gpr_mu* mu);
+
+/** Release an exclusive lock on *mu held by the calling thread.  Requires:  *mu
+   initialized; the calling thread holds an exclusive lock on *mu.  */
+GPRAPI void gpr_mu_unlock(gpr_mu* mu);
+
+/** Without blocking, attempt to acquire an exclusive lock on *mu for the
+   calling thread, then return non-zero iff success.  Fail, if any thread holds
+   the lock; succeeds with high probability if no thread holds the lock.
+   Requires:  *mu initialized.  */
+GPRAPI int gpr_mu_trylock(gpr_mu* mu);
+
+/** --- Condition variable interface ---
+
+   A while-loop should be used with gpr_cv_wait() when waiting for conditions
+   to become true.  See the example below.  Variables of type gpr_cv are
+   uninitialized when first declared.  */
+
+/** Initialize *cv.  Requires:  *cv uninitialized.  */
+GPRAPI void gpr_cv_init(gpr_cv* cv);
+
+/** Cause *cv no longer to be initialized, freeing any memory in use.  Requires:
+ *cv initialized; no other concurrent operation on *cv.*/
+GPRAPI void gpr_cv_destroy(gpr_cv* cv);
+
+/** Atomically release *mu and wait on *cv.  When the calling thread is woken
+   from *cv or the deadline abs_deadline is exceeded, execute gpr_mu_lock(mu)
+   and return whether the deadline was exceeded.  Use
+   abs_deadline==gpr_inf_future for no deadline.  abs_deadline can be either
+   an absolute deadline, or a GPR_TIMESPAN.  May return even when not
+   woken explicitly.  Requires:  *mu and *cv initialized; the calling thread
+   holds an exclusive lock on *mu.  */
+GPRAPI int gpr_cv_wait(gpr_cv* cv, gpr_mu* mu, gpr_timespec abs_deadline);
+
+/** If any threads are waiting on *cv, wake at least one.
+   Clients may treat this as an optimization of gpr_cv_broadcast()
+   for use in the case where waking more than one waiter is not useful.
+   Requires:  *cv initialized.  */
+GPRAPI void gpr_cv_signal(gpr_cv* cv);
+
+/** Wake all threads waiting on *cv.  Requires:  *cv initialized.  */
+GPRAPI void gpr_cv_broadcast(gpr_cv* cv);
+
+/** --- One-time initialization ---
+
+   gpr_once must be declared with static storage class, and initialized with
+   GPR_ONCE_INIT.  e.g.,
+     static gpr_once once_var = GPR_ONCE_INIT;     */
+
+/** Ensure that (*init_function)() has been called exactly once (for the
+   specified gpr_once instance) and then return.
+   If multiple threads call gpr_once() on the same gpr_once instance, one of
+   them will call (*init_function)(), and the others will block until that call
+   finishes.*/
+GPRAPI void gpr_once_init(gpr_once* once, void (*init_function)(void));
+
+/** --- One-time event notification ---
+
+  These operations act on a gpr_event, which should be initialized with
+  gpr_ev_init(), or with GPR_EVENT_INIT if static, e.g.,
+       static gpr_event event_var = GPR_EVENT_INIT;
+  It requires no destruction.  */
+
+/** Initialize *ev. */
+GPRAPI void gpr_event_init(gpr_event* ev);
+
+/** Set *ev so that gpr_event_get() and gpr_event_wait() will return value.
+   Requires:  *ev initialized; value != NULL; no prior or concurrent calls to
+   gpr_event_set(ev, ...) since initialization.  */
+GPRAPI void gpr_event_set(gpr_event* ev, void* value);
+
+/** Return the value set by gpr_event_set(ev, ...), or NULL if no such call has
+   completed.  If the result is non-NULL, all operations that occurred prior to
+   the gpr_event_set(ev, ...) set will be visible after this call returns.
+   Requires:  *ev initialized.  This operation is faster than acquiring a mutex
+   on most platforms.  */
+GPRAPI void* gpr_event_get(gpr_event* ev);
+
+/** Wait until *ev is set by gpr_event_set(ev, ...), or abs_deadline is
+   exceeded, then return gpr_event_get(ev).  Requires:  *ev initialized.  Use
+   abs_deadline==gpr_inf_future for no deadline.  When the event has been
+   signalled before the call, this operation is faster than acquiring a mutex
+   on most platforms.  */
+GPRAPI void* gpr_event_wait(gpr_event* ev, gpr_timespec abs_deadline);
+
+/** --- Reference counting ---
+
+   These calls act on the type gpr_refcount.  It requires no destruction.  */
+
+/** Initialize *r to value n.  */
+GPRAPI void gpr_ref_init(gpr_refcount* r, int n);
+
+/** Increment the reference count *r.  Requires *r initialized. */
+GPRAPI void gpr_ref(gpr_refcount* r);
+
+/** Increment the reference count *r.  Requires *r initialized.
+   Crashes if refcount is zero */
+GPRAPI void gpr_ref_non_zero(gpr_refcount* r);
+
+/** Increment the reference count *r by n.  Requires *r initialized, n > 0. */
+GPRAPI void gpr_refn(gpr_refcount* r, int n);
+
+/** Decrement the reference count *r and return non-zero iff it has reached
+   zero. .  Requires *r initialized. */
+GPRAPI int gpr_unref(gpr_refcount* r);
+
+/** Return non-zero iff the reference count of *r is one, and thus is owned
+   by exactly one object. */
+GPRAPI int gpr_ref_is_unique(gpr_refcount* r);
+
+/** --- Stats counters ---
+
+   These calls act on the integral type gpr_stats_counter.  It requires no
+   destruction.  Static instances may be initialized with
+       gpr_stats_counter c = GPR_STATS_INIT;
+   Beware:  These operations do not imply memory barriers.  Do not use them to
+   synchronize other events.  */
+
+/** Initialize *c to the value n. */
+GPRAPI void gpr_stats_init(gpr_stats_counter* c, intptr_t n);
+
+/** *c += inc.  Requires: *c initialized. */
+GPRAPI void gpr_stats_inc(gpr_stats_counter* c, intptr_t inc);
+
+/** Return *c.  Requires: *c initialized. */
+GPRAPI intptr_t gpr_stats_read(const gpr_stats_counter* c);
+
+/** ==================Example use of interface===================
+   A producer-consumer queue of up to N integers,
+   illustrating the use of the calls in this interface. */
+#if 0
+
+#define N 4
+
+   typedef struct queue {
+     gpr_cv non_empty;  /* Signalled when length becomes non-zero. */
+     gpr_cv non_full;   /* Signalled when length becomes non-N. */
+     gpr_mu mu;         /* Protects all fields below.
+                            (That is, except during initialization or
+                            destruction, the fields below should be accessed
+                            only by a thread that holds mu.) */
+     int head;           /* Index of head of queue 0..N-1. */
+     int length;         /* Number of valid elements in queue 0..N. */
+     int elem[N];        /* elem[head .. head+length-1] are queue elements. */
+   } queue;
+
+   /* Initialize *q. */
+   void queue_init(queue *q) {
+     gpr_mu_init(&q->mu);
+     gpr_cv_init(&q->non_empty);
+     gpr_cv_init(&q->non_full);
+     q->head = 0;
+     q->length = 0;
+   }
+
+   /* Free storage associated with *q. */
+   void queue_destroy(queue *q) {
+     gpr_mu_destroy(&q->mu);
+     gpr_cv_destroy(&q->non_empty);
+     gpr_cv_destroy(&q->non_full);
+   }
+
+   /* Wait until there is room in *q, then append x to *q. */
+   void queue_append(queue *q, int x) {
+     gpr_mu_lock(&q->mu);
+     /* To wait for a predicate without a deadline, loop on the negation of the
+        predicate, and use gpr_cv_wait(..., gpr_inf_future) inside the loop
+        to release the lock, wait, and reacquire on each iteration.  Code that
+        makes the condition true should use gpr_cv_broadcast() on the
+        corresponding condition variable.  The predicate must be on state
+        protected by the lock.  */
+     while (q->length == N) {
+       gpr_cv_wait(&q->non_full, &q->mu, gpr_inf_future);
+     }
+     if (q->length == 0) {  /* Wake threads blocked in queue_remove(). */
+       /* It's normal to use gpr_cv_broadcast() or gpr_signal() while
+          holding the lock. */
+       gpr_cv_broadcast(&q->non_empty);
+     }
+     q->elem[(q->head + q->length) % N] = x;
+     q->length++;
+     gpr_mu_unlock(&q->mu);
+   }
+
+   /* If it can be done without blocking, append x to *q and return non-zero.
+      Otherwise return 0. */
+   int queue_try_append(queue *q, int x) {
+     int result = 0;
+     if (gpr_mu_trylock(&q->mu)) {
+       if (q->length != N) {
+         if (q->length == 0) {  /* Wake threads blocked in queue_remove(). */
+           gpr_cv_broadcast(&q->non_empty);
+         }
+         q->elem[(q->head + q->length) % N] = x;
+         q->length++;
+         result = 1;
+       }
+       gpr_mu_unlock(&q->mu);
+     }
+     return result;
+   }
+
+   /* Wait until the *q is non-empty or deadline abs_deadline passes.  If the
+      queue is non-empty, remove its head entry, place it in *head, and return
+      non-zero.  Otherwise return 0.  */
+   int queue_remove(queue *q, int *head, gpr_timespec abs_deadline) {
+     int result = 0;
+     gpr_mu_lock(&q->mu);
+     /* To wait for a predicate with a deadline, loop on the negation of the
+        predicate or until gpr_cv_wait() returns true.  Code that makes
+        the condition true should use gpr_cv_broadcast() on the corresponding
+        condition variable.  The predicate must be on state protected by the
+        lock. */
+     while (q->length == 0 &&
+            !gpr_cv_wait(&q->non_empty, &q->mu, abs_deadline)) {
+     }
+     if (q->length != 0) {    /* Queue is non-empty. */
+       result = 1;
+       if (q->length == N) {  /* Wake threads blocked in queue_append(). */
+         gpr_cv_broadcast(&q->non_full);
+       }
+       *head = q->elem[q->head];
+       q->head = (q->head + 1) % N;
+       q->length--;
+     } /* else deadline exceeded */
+     gpr_mu_unlock(&q->mu);
+     return result;
+   }
+#endif /* 0 */
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif /* GRPC_SUPPORT_SYNC_H */
diff --git a/grpc/spm-core-include/grpc/support/sync_abseil.h b/grpc/spm-core-include/grpc/support/sync_abseil.h
new file mode 100644
index 00000000..3ee73489
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/sync_abseil.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_SYNC_ABSEIL_H
+#define GRPC_SUPPORT_SYNC_ABSEIL_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/sync_abseil.h>
+
+#endif /* GRPC_SUPPORT_SYNC_ABSEIL_H */
diff --git a/grpc/spm-core-include/grpc/support/sync_custom.h b/grpc/spm-core-include/grpc/support/sync_custom.h
new file mode 100644
index 00000000..27cf0e05
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/sync_custom.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_SYNC_CUSTOM_H
+#define GRPC_SUPPORT_SYNC_CUSTOM_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/sync_custom.h>
+
+#endif /* GRPC_SUPPORT_SYNC_CUSTOM_H */
diff --git a/grpc/spm-core-include/grpc/support/sync_generic.h b/grpc/spm-core-include/grpc/support/sync_generic.h
new file mode 100644
index 00000000..93028c4a
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/sync_generic.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_SYNC_GENERIC_H
+#define GRPC_SUPPORT_SYNC_GENERIC_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/sync_generic.h>
+
+#endif /* GRPC_SUPPORT_SYNC_GENERIC_H */
diff --git a/grpc/spm-core-include/grpc/support/sync_posix.h b/grpc/spm-core-include/grpc/support/sync_posix.h
new file mode 100644
index 00000000..3dce7ee4
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/sync_posix.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_SYNC_POSIX_H
+#define GRPC_SUPPORT_SYNC_POSIX_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/sync_posix.h>
+
+#endif /* GRPC_SUPPORT_SYNC_POSIX_H */
diff --git a/grpc/spm-core-include/grpc/support/sync_windows.h b/grpc/spm-core-include/grpc/support/sync_windows.h
new file mode 100644
index 00000000..a493c864
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/sync_windows.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_SYNC_WINDOWS_H
+#define GRPC_SUPPORT_SYNC_WINDOWS_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/sync_windows.h>
+
+#endif /* GRPC_SUPPORT_SYNC_WINDOWS_H */
diff --git a/grpc/spm-core-include/grpc/support/thd_id.h b/grpc/spm-core-include/grpc/support/thd_id.h
new file mode 100644
index 00000000..e9b2b7ec
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/thd_id.h
@@ -0,0 +1,44 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_THD_ID_H
+#define GRPC_SUPPORT_THD_ID_H
+/** Thread ID interface for GPR.
+
+   Used by some wrapped languages for logging purposes.
+
+   Types
+        gpr_thd_id        a unique opaque identifier for a thread.
+ */
+
+#include <grpc/support/port_platform.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef uintptr_t gpr_thd_id;
+
+/** Returns the identifier of the current thread. */
+GPRAPI gpr_thd_id gpr_thd_currentid(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_SUPPORT_THD_ID_H */
diff --git a/grpc/spm-core-include/grpc/support/time.h b/grpc/spm-core-include/grpc/support/time.h
new file mode 100644
index 00000000..44aead5e
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/time.h
@@ -0,0 +1,92 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_TIME_H
+#define GRPC_SUPPORT_TIME_H
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/impl/codegen/gpr_types.h>
+
+#include <stddef.h>
+#include <time.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Time constants. */
+GPRAPI gpr_timespec
+gpr_time_0(gpr_clock_type type); /** The zero time interval. */
+GPRAPI gpr_timespec gpr_inf_future(gpr_clock_type type); /** The far future */
+GPRAPI gpr_timespec gpr_inf_past(gpr_clock_type type);   /** The far past. */
+
+#define GPR_MS_PER_SEC 1000
+#define GPR_US_PER_SEC 1000000
+#define GPR_NS_PER_SEC 1000000000
+#define GPR_NS_PER_MS 1000000
+#define GPR_NS_PER_US 1000
+#define GPR_US_PER_MS 1000
+
+/** initialize time subsystem */
+GPRAPI void gpr_time_init(void);
+
+/** Return the current time measured from the given clocks epoch. */
+GPRAPI gpr_timespec gpr_now(gpr_clock_type clock);
+
+/** Convert a timespec from one clock to another */
+GPRAPI gpr_timespec gpr_convert_clock_type(gpr_timespec t,
+                                           gpr_clock_type clock_type);
+
+/** Return -ve, 0, or +ve according to whether a < b, a == b, or a > b
+   respectively.  */
+GPRAPI int gpr_time_cmp(gpr_timespec a, gpr_timespec b);
+
+GPRAPI gpr_timespec gpr_time_max(gpr_timespec a, gpr_timespec b);
+GPRAPI gpr_timespec gpr_time_min(gpr_timespec a, gpr_timespec b);
+
+/** Add and subtract times.  Calculations saturate at infinities. */
+GPRAPI gpr_timespec gpr_time_add(gpr_timespec a, gpr_timespec b);
+GPRAPI gpr_timespec gpr_time_sub(gpr_timespec a, gpr_timespec b);
+
+/** Return a timespec representing a given number of time units. INT64_MIN is
+   interpreted as gpr_inf_past, and INT64_MAX as gpr_inf_future.  */
+GPRAPI gpr_timespec gpr_time_from_micros(int64_t us, gpr_clock_type clock_type);
+GPRAPI gpr_timespec gpr_time_from_nanos(int64_t ns, gpr_clock_type clock_type);
+GPRAPI gpr_timespec gpr_time_from_millis(int64_t ms, gpr_clock_type clock_type);
+GPRAPI gpr_timespec gpr_time_from_seconds(int64_t s, gpr_clock_type clock_type);
+GPRAPI gpr_timespec gpr_time_from_minutes(int64_t m, gpr_clock_type clock_type);
+GPRAPI gpr_timespec gpr_time_from_hours(int64_t h, gpr_clock_type clock_type);
+
+GPRAPI int32_t gpr_time_to_millis(gpr_timespec timespec);
+
+/** Return 1 if two times are equal or within threshold of each other,
+   0 otherwise */
+GPRAPI int gpr_time_similar(gpr_timespec a, gpr_timespec b,
+                            gpr_timespec threshold);
+
+/** Sleep until at least 'until' - an absolute timeout */
+GPRAPI void gpr_sleep_until(gpr_timespec until);
+
+GPRAPI double gpr_timespec_to_micros(gpr_timespec t);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_SUPPORT_TIME_H */
diff --git a/grpc/spm-core-include/grpc/support/workaround_list.h b/grpc/spm-core-include/grpc/support/workaround_list.h
new file mode 100644
index 00000000..e28dfa14
--- /dev/null
+++ b/grpc/spm-core-include/grpc/support/workaround_list.h
@@ -0,0 +1,31 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_WORKAROUND_LIST_H
+#define GRPC_SUPPORT_WORKAROUND_LIST_H
+
+/* The list of IDs of server workarounds currently maintained by gRPC. For
+ * explanation and detailed descriptions of workarounds, see
+ * /doc/workarounds.md
+ */
+typedef enum {
+  GRPC_WORKAROUND_ID_CRONET_COMPRESSION = 0,
+  GRPC_MAX_WORKAROUND_ID
+} grpc_workaround_list;
+
+#endif /* GRPC_SUPPORT_WORKAROUND_LIST_H */