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// 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_REMOTE_MESSAGE_PIPE_BOOTSTRAP_H_
#define MOJO_EDK_SYSTEM_REMOTE_MESSAGE_PIPE_BOOTSTRAP_H_
#include <string>
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/message_loop/message_loop.h"
#include "base/task_runner.h"
#include "mojo/edk/embedder/scoped_platform_handle.h"
#include "mojo/edk/system/channel.h"
#include "mojo/edk/system/ports/name.h"
#include "mojo/edk/system/ports/port_ref.h"
namespace mojo {
namespace edk {
class NodeController;
// This is used by Core to negotiate a new cross-process message pipe given
// an arbitrary platform channel. Both ends of the channel must be passed to
// RemoteMessagePipeBootstrap::Create() in their respective processes.
//
// The bootstrapping procedure the same on either end:
//
// 1. Select a local port P to be merged with a remote port.
// 2. Write the local node name and P's name to the bootstrap pipe.
// 3. When a message is read from the pipe:
// - If it's the first message read, extract the remote node+port name and
// and send an empty ACK message on the pipe.
// - If it's the second message read, close the channel, and delete |this|.
// 4. When an error occus on the pipe, delete |this|.
//
// Excluding irrecoverable error conditions such as either process dying,
// armageddon, etc., this ensures neither end closes the channel until both ends
// are aware of each other's port-to-merge.
//
// At step 3, one side of the channel is chosen to issue a message at the Ports
// layer which eventually merges the two ports.
class RemoteMessagePipeBootstrap
: public Channel::Delegate,
public base::MessageLoop::DestructionObserver {
public:
~RemoteMessagePipeBootstrap() override;
// |port| must be a reference to an uninitialized local port.
static void Create(NodeController* node_controller,
ScopedPlatformHandle platform_handle,
const ports::PortRef& port);
protected:
explicit RemoteMessagePipeBootstrap(NodeController* node_controller,
ScopedPlatformHandle platform_handle,
const ports::PortRef& port);
void ShutDown();
bool shutting_down_ = false;
NodeController* node_controller_;
const ports::PortRef local_port_;
scoped_refptr<base::TaskRunner> io_task_runner_;
scoped_refptr<Channel> channel_;
bool peer_info_received_ = false;
private:
// base::MessageLoop::DestructionObserver:
void WillDestroyCurrentMessageLoop() override;
// Channel::Delegate:
void OnChannelMessage(const void* payload,
size_t payload_size,
ScopedPlatformHandleVectorPtr handles) override;
void OnChannelError() override;
void ShutDownNow();
DISALLOW_COPY_AND_ASSIGN(RemoteMessagePipeBootstrap);
};
} // namespace edk
} // namespace mojo
#endif // MOJO_EDK_SYSTEM_REMOTE_MESSAGE_PIPE_BOOTSTRAP_H_
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