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// Copyright 2014 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 IPC_IPC_MESSAGE_PIPE_READER_H_
#define IPC_IPC_MESSAGE_PIPE_READER_H_
#include <stdint.h>
#include <memory>
#include <vector>
#include "base/atomicops.h"
#include "base/compiler_specific.h"
#include "base/component_export.h"
#include "base/macros.h"
#include "base/process/process_handle.h"
#include "base/threading/thread_checker.h"
#include "ipc/ipc.mojom.h"
#include "ipc/ipc_message.h"
#include "mojo/public/cpp/bindings/associated_binding.h"
#include "mojo/public/cpp/bindings/scoped_interface_endpoint_handle.h"
#include "mojo/public/cpp/system/core.h"
#include "mojo/public/cpp/system/message_pipe.h"
#include "mojo/public/interfaces/bindings/native_struct.mojom.h"
namespace IPC {
namespace internal {
// A helper class to handle bytestream directly over mojo::MessagePipe
// in template-method pattern. MessagePipeReader manages the lifetime
// of given MessagePipe and participates the event loop, and
// read the stream and call the client when it is ready.
//
// Each client has to:
//
// * Provide a subclass implemenation of a specific use of a MessagePipe
// and implement callbacks.
// * Create the subclass instance with a MessagePipeHandle.
// The constructor automatically start listening on the pipe.
//
// All functions must be called on the IO thread, except for Send(), which can
// be called on any thread. All |Delegate| functions will be called on the IO
// thread.
//
class COMPONENT_EXPORT(IPC) MessagePipeReader : public mojom::Channel {
public:
class Delegate {
public:
virtual void OnPeerPidReceived(int32_t peer_pid) = 0;
virtual void OnMessageReceived(const Message& message) = 0;
virtual void OnBrokenDataReceived() = 0;
virtual void OnPipeError() = 0;
virtual void OnAssociatedInterfaceRequest(
const std::string& name,
mojo::ScopedInterfaceEndpointHandle handle) = 0;
};
// Builds a reader that reads messages from |receive_handle| and lets
// |delegate| know.
//
// |pipe| is the message pipe handle corresponding to the channel's master
// interface. This is the message pipe underlying both |sender| and
// |receiver|.
//
// Both |sender| and |receiver| must be non-null.
//
// Note that MessagePipeReader doesn't delete |delegate|.
MessagePipeReader(mojo::MessagePipeHandle pipe,
mojom::ChannelAssociatedPtr sender,
mojo::AssociatedInterfaceRequest<mojom::Channel> receiver,
Delegate* delegate);
~MessagePipeReader() override;
// Close and destroy the MessagePipe.
void Close();
// Return true if the MessagePipe is alive.
bool IsValid() { return sender_.is_bound(); }
// Sends an IPC::Message to the other end of the pipe. Safe to call from any
// thread.
bool Send(std::unique_ptr<Message> message);
// Requests an associated interface from the other end of the pipe.
void GetRemoteInterface(const std::string& name,
mojo::ScopedInterfaceEndpointHandle handle);
mojom::ChannelAssociatedPtr& sender() { return sender_; }
protected:
void OnPipeClosed();
void OnPipeError(MojoResult error);
private:
// mojom::Channel:
void SetPeerPid(int32_t peer_pid) override;
void Receive(base::span<const uint8_t> data,
base::Optional<std::vector<mojo::native::SerializedHandlePtr>>
handles) override;
void GetAssociatedInterface(
const std::string& name,
mojom::GenericInterfaceAssociatedRequest request) override;
// |delegate_| is null once the message pipe is closed.
Delegate* delegate_;
mojom::ChannelAssociatedPtr sender_;
mojo::AssociatedBinding<mojom::Channel> binding_;
base::ThreadChecker thread_checker_;
DISALLOW_COPY_AND_ASSIGN(MessagePipeReader);
};
} // namespace internal
} // namespace IPC
#endif // IPC_IPC_MESSAGE_PIPE_READER_H_