Migrate libmojo repository into libchrome, part 2.

am: b268b43ac6

Change-Id: I7b2c3d7cfed03673c33eb497be20e238bd0aac33

1 files changed, 378 insertions, 0 deletions

diff --git a/mojo/edk/system/node_controller.h b/mojo/edk/system/node_controller.h
new file mode 100644
index 0000000000..46a2d61208
--- /dev/null
+++ b/mojo/edk/system/node_controller.h
@@ -0,0 +1,378 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MOJO_EDK_SYSTEM_NODE_CONTROLLER_H_
+#define MOJO_EDK_SYSTEM_NODE_CONTROLLER_H_
+
+#include <memory>
+#include <queue>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/containers/hash_tables.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/task_runner.h"
+#include "mojo/edk/embedder/platform_handle_vector.h"
+#include "mojo/edk/embedder/platform_shared_buffer.h"
+#include "mojo/edk/embedder/scoped_platform_handle.h"
+#include "mojo/edk/system/atomic_flag.h"
+#include "mojo/edk/system/node_channel.h"
+#include "mojo/edk/system/ports/name.h"
+#include "mojo/edk/system/ports/node.h"
+#include "mojo/edk/system/ports/node_delegate.h"
+
+namespace base {
+class PortProvider;
+}
+
+namespace mojo {
+namespace edk {
+
+class Broker;
+class Core;
+class MachPortRelay;
+class PortsMessage;
+
+// The owner of ports::Node which facilitates core EDK implementation. All
+// public interface methods are safe to call from any thread.
+class NodeController : public ports::NodeDelegate,
+                       public NodeChannel::Delegate {
+ public:
+  class PortObserver : public ports::UserData {
+   public:
+    virtual void OnPortStatusChanged() = 0;
+
+   protected:
+    ~PortObserver() override {}
+  };
+
+  // |core| owns and out-lives us.
+  explicit NodeController(Core* core);
+  ~NodeController() override;
+
+  const ports::NodeName& name() const { return name_; }
+  Core* core() const { return core_; }
+  ports::Node* node() const { return node_.get(); }
+  scoped_refptr<base::TaskRunner> io_task_runner() const {
+    return io_task_runner_;
+  }
+
+#if defined(OS_MACOSX) && !defined(OS_IOS)
+  // Create the relay used to transfer mach ports between processes.
+  void CreateMachPortRelay(base::PortProvider* port_provider);
+#endif
+
+  // Called exactly once, shortly after construction, and before any other
+  // methods are called on this object.
+  void SetIOTaskRunner(scoped_refptr<base::TaskRunner> io_task_runner);
+
+  // Connects this node to a child node. This node will initiate a handshake.
+  void ConnectToChild(base::ProcessHandle process_handle,
+                      ConnectionParams connection_params,
+                      const std::string& child_token,
+                      const ProcessErrorCallback& process_error_callback);
+
+  // Closes all reserved ports which associated with the child process
+  // |child_token|.
+  void CloseChildPorts(const std::string& child_token);
+
+  // Close a connection to a peer associated with |peer_token|.
+  void ClosePeerConnection(const std::string& peer_token);
+
+  // Connects this node to a parent node. The parent node will initiate a
+  // handshake.
+  void ConnectToParent(ConnectionParams connection_params);
+
+  // Connects this node to a peer node. On success, |port| will be merged with
+  // the corresponding port in the peer node.
+  void ConnectToPeer(ConnectionParams connection_params,
+                     const ports::PortRef& port,
+                     const std::string& peer_token);
+
+  // Sets a port's observer. If |observer| is null the port's current observer
+  // is removed.
+  void SetPortObserver(const ports::PortRef& port,
+                       scoped_refptr<PortObserver> observer);
+
+  // Closes a port. Use this in lieu of calling Node::ClosePort() directly, as
+  // it ensures the port's observer has also been removed.
+  void ClosePort(const ports::PortRef& port);
+
+  // Sends a message on a port to its peer.
+  int SendMessage(const ports::PortRef& port_ref,
+                  std::unique_ptr<PortsMessage> message);
+
+  // Reserves a local port |port| associated with |token|. A peer holding a copy
+  // of |token| can merge one of its own ports into this one.
+  void ReservePort(const std::string& token, const ports::PortRef& port,
+                   const std::string& child_token);
+
+  // Merges a local port |port| into a port reserved by |token| in the parent.
+  void MergePortIntoParent(const std::string& token,
+                           const ports::PortRef& port);
+
+  // Merges two local ports together.
+  int MergeLocalPorts(const ports::PortRef& port0, const ports::PortRef& port1);
+
+  // Creates a new shared buffer for use in the current process.
+  scoped_refptr<PlatformSharedBuffer> CreateSharedBuffer(size_t num_bytes);
+
+  // Request that the Node be shut down cleanly. This may take an arbitrarily
+  // long time to complete, at which point |callback| will be called.
+  //
+  // Note that while it is safe to continue using the NodeController's public
+  // interface after requesting shutdown, you do so at your own risk and there
+  // is NO guarantee that new messages will be sent or ports will complete
+  // transfer.
+  void RequestShutdown(const base::Closure& callback);
+
+  // Notifies the NodeController that we received a bad message from the given
+  // node.
+  void NotifyBadMessageFrom(const ports::NodeName& source_node,
+                            const std::string& error);
+
+ private:
+  friend Core;
+
+  using NodeMap = std::unordered_map<ports::NodeName,
+                                     scoped_refptr<NodeChannel>>;
+  using OutgoingMessageQueue = std::queue<Channel::MessagePtr>;
+
+  struct ReservedPort {
+    ports::PortRef port;
+    const std::string child_token;
+  };
+
+  struct PeerConnection {
+    PeerConnection();
+    PeerConnection(const PeerConnection& other);
+    PeerConnection(PeerConnection&& other);
+    PeerConnection(scoped_refptr<NodeChannel> channel,
+                   const ports::PortRef& local_port,
+                   const std::string& peer_token);
+    ~PeerConnection();
+
+    PeerConnection& operator=(const PeerConnection& other);
+    PeerConnection& operator=(PeerConnection&& other);
+
+
+    scoped_refptr<NodeChannel> channel;
+    ports::PortRef local_port;
+    std::string peer_token;
+  };
+
+  void ConnectToChildOnIOThread(
+      base::ProcessHandle process_handle,
+      ConnectionParams connection_params,
+      ports::NodeName token,
+      const ProcessErrorCallback& process_error_callback);
+  void ConnectToParentOnIOThread(ConnectionParams connection_params);
+
+  void ConnectToPeerOnIOThread(ConnectionParams connection_params,
+                               ports::NodeName token,
+                               ports::PortRef port,
+                               const std::string& peer_token);
+  void ClosePeerConnectionOnIOThread(const std::string& node_name);
+
+  scoped_refptr<NodeChannel> GetPeerChannel(const ports::NodeName& name);
+  scoped_refptr<NodeChannel> GetParentChannel();
+  scoped_refptr<NodeChannel> GetBrokerChannel();
+
+  void AddPeer(const ports::NodeName& name,
+               scoped_refptr<NodeChannel> channel,
+               bool start_channel);
+  void DropPeer(const ports::NodeName& name, NodeChannel* channel);
+  void SendPeerMessage(const ports::NodeName& name,
+                       ports::ScopedMessage message);
+  void AcceptIncomingMessages();
+  void ProcessIncomingMessages();
+  void DropAllPeers();
+
+  // ports::NodeDelegate:
+  void GenerateRandomPortName(ports::PortName* port_name) override;
+  void AllocMessage(size_t num_header_bytes,
+                    ports::ScopedMessage* message) override;
+  void ForwardMessage(const ports::NodeName& node,
+                      ports::ScopedMessage message) override;
+  void BroadcastMessage(ports::ScopedMessage message) override;
+  void PortStatusChanged(const ports::PortRef& port) override;
+
+  // NodeChannel::Delegate:
+  void OnAcceptChild(const ports::NodeName& from_node,
+                     const ports::NodeName& parent_name,
+                     const ports::NodeName& token) override;
+  void OnAcceptParent(const ports::NodeName& from_node,
+                      const ports::NodeName& token,
+                      const ports::NodeName& child_name) override;
+  void OnAddBrokerClient(const ports::NodeName& from_node,
+                         const ports::NodeName& client_name,
+                         base::ProcessHandle process_handle) override;
+  void OnBrokerClientAdded(const ports::NodeName& from_node,
+                           const ports::NodeName& client_name,
+                           ScopedPlatformHandle broker_channel) override;
+  void OnAcceptBrokerClient(const ports::NodeName& from_node,
+                            const ports::NodeName& broker_name,
+                            ScopedPlatformHandle broker_channel) override;
+  void OnPortsMessage(const ports::NodeName& from_node,
+                      Channel::MessagePtr message) override;
+  void OnRequestPortMerge(const ports::NodeName& from_node,
+                          const ports::PortName& connector_port_name,
+                          const std::string& token) override;
+  void OnRequestIntroduction(const ports::NodeName& from_node,
+                             const ports::NodeName& name) override;
+  void OnIntroduce(const ports::NodeName& from_node,
+                   const ports::NodeName& name,
+                   ScopedPlatformHandle channel_handle) override;
+  void OnBroadcast(const ports::NodeName& from_node,
+                   Channel::MessagePtr message) override;
+#if defined(OS_WIN) || (defined(OS_MACOSX) && !defined(OS_IOS))
+  void OnRelayPortsMessage(const ports::NodeName& from_node,
+                           base::ProcessHandle from_process,
+                           const ports::NodeName& destination,
+                           Channel::MessagePtr message) override;
+  void OnPortsMessageFromRelay(const ports::NodeName& from_node,
+                               const ports::NodeName& source_node,
+                               Channel::MessagePtr message) override;
+#endif
+  void OnAcceptPeer(const ports::NodeName& from_node,
+                    const ports::NodeName& token,
+                    const ports::NodeName& peer_name,
+                    const ports::PortName& port_name) override;
+  void OnChannelError(const ports::NodeName& from_node,
+                      NodeChannel* channel) override;
+#if defined(OS_MACOSX) && !defined(OS_IOS)
+  MachPortRelay* GetMachPortRelay() override;
+#endif
+
+  // Cancels all pending port merges. These are merges which are supposed to
+  // be requested from the parent ASAP, and they may be cancelled if the
+  // connection to the parent is broken or never established.
+  void CancelPendingPortMerges();
+
+  // Marks this NodeController for destruction when the IO thread shuts down.
+  // This is used in case Core is torn down before the IO thread. Must only be
+  // called on the IO thread.
+  void DestroyOnIOThreadShutdown();
+
+  // If there is a registered shutdown callback (meaning shutdown has been
+  // requested, this checks the Node's status to see if clean shutdown is
+  // possible. If so, shutdown is performed and the shutdown callback is run.
+  void AttemptShutdownIfRequested();
+
+  // These are safe to access from any thread as long as the Node is alive.
+  Core* const core_;
+  const ports::NodeName name_;
+  const std::unique_ptr<ports::Node> node_;
+  scoped_refptr<base::TaskRunner> io_task_runner_;
+
+  // Guards |peers_| and |pending_peer_messages_|.
+  base::Lock peers_lock_;
+
+  // Channels to known peers, including parent and children, if any.
+  NodeMap peers_;
+
+  // Outgoing message queues for peers we've heard of but can't yet talk to.
+  std::unordered_map<ports::NodeName, OutgoingMessageQueue>
+      pending_peer_messages_;
+
+  // Guards |reserved_ports_| and |pending_child_tokens_|.
+  base::Lock reserved_ports_lock_;
+
+  // Ports reserved by token. Key is the port token.
+  base::hash_map<std::string, ReservedPort> reserved_ports_;
+  // TODO(amistry): This _really_ needs to be a bimap. Unfortunately, we don't
+  // have one yet :(
+  std::unordered_map<ports::NodeName, std::string> pending_child_tokens_;
+
+  // Guards |pending_port_merges_| and |reject_pending_merges_|.
+  base::Lock pending_port_merges_lock_;
+
+  // A set of port merge requests awaiting parent connection.
+  std::vector<std::pair<std::string, ports::PortRef>> pending_port_merges_;
+
+  // Indicates that new merge requests should be rejected because the parent has
+  // disconnected.
+  bool reject_pending_merges_ = false;
+
+  // Guards |parent_name_| and |bootstrap_parent_channel_|.
+  base::Lock parent_lock_;
+
+  // The name of our parent node, if any.
+  ports::NodeName parent_name_;
+
+  // A temporary reference to the parent channel before we know their name.
+  scoped_refptr<NodeChannel> bootstrap_parent_channel_;
+
+  // Guards |broker_name_|, |pending_broker_clients_|, and
+  // |pending_relay_messages_|.
+  base::Lock broker_lock_;
+
+  // The name of our broker node, if any.
+  ports::NodeName broker_name_;
+
+  // A queue of pending child names waiting to be connected to a broker.
+  std::queue<ports::NodeName> pending_broker_clients_;
+
+  // Messages waiting to be relayed by the broker once it's known.
+  std::unordered_map<ports::NodeName, OutgoingMessageQueue>
+      pending_relay_messages_;
+
+  // Guards |incoming_messages_| and |incoming_messages_task_posted_|.
+  base::Lock messages_lock_;
+  std::queue<ports::ScopedMessage> incoming_messages_;
+  // Ensures that there is only one incoming messages task posted to the IO
+  // thread.
+  bool incoming_messages_task_posted_ = false;
+  // Flag to fast-path checking |incoming_messages_|.
+  AtomicFlag incoming_messages_flag_;
+
+  // Guards |shutdown_callback_|.
+  base::Lock shutdown_lock_;
+
+  // Set by RequestShutdown(). If this is non-null, the controller will
+  // begin polling the Node to see if clean shutdown is possible any time the
+  // Node's state is modified by the controller.
+  base::Closure shutdown_callback_;
+  // Flag to fast-path checking |shutdown_callback_|.
+  AtomicFlag shutdown_callback_flag_;
+
+  // All other fields below must only be accessed on the I/O thread, i.e., the
+  // thread on which core_->io_task_runner() runs tasks.
+
+  // Channels to children during handshake.
+  NodeMap pending_children_;
+
+  using PeerNodeMap =
+      std::unordered_map<ports::NodeName, PeerConnection>;
+  PeerNodeMap peer_connections_;
+
+  // Maps from peer token to node name, pending or not.
+  std::unordered_map<std::string, ports::NodeName> peers_by_token_;
+
+  // Indicates whether this object should delete itself on IO thread shutdown.
+  // Must only be accessed from the IO thread.
+  bool destroy_on_io_thread_shutdown_ = false;
+
+#if !defined(OS_MACOSX) && !defined(OS_NACL_SFI)
+  // Broker for sync shared buffer creation in children.
+  std::unique_ptr<Broker> broker_;
+#endif
+
+#if defined(OS_MACOSX) && !defined(OS_IOS)
+  base::Lock mach_port_relay_lock_;
+  // Relay for transferring mach ports to/from children.
+  std::unique_ptr<MachPortRelay> mach_port_relay_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(NodeController);
+};
+
+}  // namespace edk
+}  // namespace mojo
+
+#endif  // MOJO_EDK_SYSTEM_NODE_CONTROLLER_H_