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/*
*
* Copyright 2019 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.
*
*/
#include <grpc/support/port_platform.h>
#include "src/core/lib/iomgr/port.h"
#if GRPC_ARES == 1 && defined(GRPC_UV)
#include "absl/strings/str_format.h"
#include <ares.h>
#include <uv.h>
#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include <grpc/support/time.h>
#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
#include "src/core/lib/gpr/string.h"
#include "src/core/lib/iomgr/work_serializer.h"
namespace grpc_core {
void ares_uv_poll_cb(uv_poll_t* handle, int status, int events);
void ares_uv_poll_close_cb(uv_handle_t* handle) { delete handle; }
class GrpcPolledFdLibuv : public GrpcPolledFd {
public:
GrpcPolledFdLibuv(ares_socket_t as,
std::shared_ptr<WorkSerializer> work_serializer)
: name_(absl::StrFormat("c-ares socket: %" PRIdPTR, (intptr_t)as)),
as_(as),
work_serializer_(std::move(work_serializer)) {
handle_ = new uv_poll_t();
uv_poll_init_socket(uv_default_loop(), handle_, as);
handle_->data = this;
}
void RegisterForOnReadableLocked(grpc_closure* read_closure) override {
GPR_ASSERT(read_closure_ == nullptr);
GPR_ASSERT((poll_events_ & UV_READABLE) == 0);
read_closure_ = read_closure;
poll_events_ |= UV_READABLE;
uv_poll_start(handle_, poll_events_, ares_uv_poll_cb);
}
void RegisterForOnWriteableLocked(grpc_closure* write_closure) override {
GPR_ASSERT(write_closure_ == nullptr);
GPR_ASSERT((poll_events_ & UV_WRITABLE) == 0);
write_closure_ = write_closure;
poll_events_ |= UV_WRITABLE;
uv_poll_start(handle_, poll_events_, ares_uv_poll_cb);
}
bool IsFdStillReadableLocked() override {
/* uv_poll_t is based on poll, which is level triggered. So, if cares
* leaves some data unread, the event will trigger again. */
return false;
}
void ShutdownInternalLocked(grpc_error* error) {
uv_poll_stop(handle_);
uv_close(reinterpret_cast<uv_handle_t*>(handle_), ares_uv_poll_close_cb);
if (read_closure_ != nullptr) {
grpc_core::ExecCtx::Run(DEBUG_LOCATION, read_closure_,
GRPC_ERROR_CANCELLED);
}
if (write_closure_ != nullptr) {
grpc_core::ExecCtx::Run(DEBUG_LOCATION, write_closure_,
GRPC_ERROR_CANCELLED);
}
}
void ShutdownLocked(grpc_error* error) override {
if (grpc_core::ExecCtx::Get() == nullptr) {
grpc_core::ExecCtx exec_ctx;
ShutdownInternalLocked(error);
} else {
ShutdownInternalLocked(error);
}
}
ares_socket_t GetWrappedAresSocketLocked() override { return as_; }
const char* GetName() override { return name_.c_str(); }
// TODO(apolcyn): Data members should be private.
std::string name_;
ares_socket_t as_;
uv_poll_t* handle_;
grpc_closure* read_closure_ = nullptr;
grpc_closure* write_closure_ = nullptr;
int poll_events_ = 0;
std::shared_ptr<WorkSerializer> work_serializer_;
};
struct AresUvPollCbArg {
AresUvPollCbArg(uv_poll_t* handle, int status, int events)
: handle(handle), status(status), events(events) {}
uv_poll_t* handle;
int status;
int events;
};
static void ares_uv_poll_cb_locked(AresUvPollCbArg* arg) {
std::unique_ptr<AresUvPollCbArg> arg_struct(arg);
uv_poll_t* handle = arg_struct->handle;
int status = arg_struct->status;
int events = arg_struct->events;
GrpcPolledFdLibuv* polled_fd =
reinterpret_cast<GrpcPolledFdLibuv*>(handle->data);
grpc_error* error = GRPC_ERROR_NONE;
if (status < 0) {
error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("cares polling error");
error =
grpc_error_set_str(error, GRPC_ERROR_STR_OS_ERROR,
grpc_slice_from_static_string(uv_strerror(status)));
}
if (events & UV_READABLE) {
GPR_ASSERT(polled_fd->read_closure_ != nullptr);
grpc_core::ExecCtx::Run(DEBUG_LOCATION, polled_fd->read_closure_, error);
polled_fd->read_closure_ = nullptr;
polled_fd->poll_events_ &= ~UV_READABLE;
}
if (events & UV_WRITABLE) {
GPR_ASSERT(polled_fd->write_closure_ != nullptr);
grpc_core::ExecCtx::Run(DEBUG_LOCATION, polled_fd->write_closure_, error);
polled_fd->write_closure_ = nullptr;
polled_fd->poll_events_ &= ~UV_WRITABLE;
}
uv_poll_start(handle, polled_fd->poll_events_, ares_uv_poll_cb);
}
void ares_uv_poll_cb(uv_poll_t* handle, int status, int events) {
grpc_core::ExecCtx exec_ctx;
GrpcPolledFdLibuv* polled_fd =
reinterpret_cast<GrpcPolledFdLibuv*>(handle->data);
AresUvPollCbArg* arg = new AresUvPollCbArg(handle, status, events);
polled_fd->work_serializer_->Run([arg]() { ares_uv_poll_cb_locked(arg); },
DEBUG_LOCATION);
}
class GrpcPolledFdFactoryLibuv : public GrpcPolledFdFactory {
public:
GrpcPolledFd* NewGrpcPolledFdLocked(
ares_socket_t as, grpc_pollset_set* driver_pollset_set,
std::shared_ptr<WorkSerializer> work_serializer) override {
return new GrpcPolledFdLibuv(as, std::move(work_serializer));
}
void ConfigureAresChannelLocked(ares_channel channel) override {}
};
std::unique_ptr<GrpcPolledFdFactory> NewGrpcPolledFdFactory(
std::shared_ptr<WorkSerializer> work_serializer) {
return absl::make_unique<GrpcPolledFdFactoryLibuv>();
}
} // namespace grpc_core
#endif /* GRPC_ARES == 1 && defined(GRPC_UV) */
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