| // Copyright (c) 2012 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_CHANNEL_NACL_H_ |
| #define IPC_IPC_CHANNEL_NACL_H_ |
| |
| #include <deque> |
| #include <string> |
| |
| #include "base/memory/linked_ptr.h" |
| #include "base/memory/scoped_ptr.h" |
| #include "base/memory/weak_ptr.h" |
| #include "base/process/process.h" |
| #include "base/threading/simple_thread.h" |
| #include "ipc/ipc_channel.h" |
| #include "ipc/ipc_channel_reader.h" |
| |
| namespace IPC { |
| |
| // Contains the results from one call to imc_recvmsg (data and file |
| // descriptors). |
| struct MessageContents; |
| |
| // Similar to the Posix version of ChannelImpl but for Native Client code. |
| // This is somewhat different because sendmsg/recvmsg here do not follow POSIX |
| // semantics. Instead, they are implemented by a custom embedding of |
| // NaClDescCustom. See NaClIPCAdapter for the trusted-side implementation. |
| // |
| // We don't need to worry about complicated set up and READWRITE mode for |
| // sharing handles. We also currently do not support passing file descriptors or |
| // named pipes, and we use background threads to emulate signaling when we can |
| // read or write without blocking. |
| class Channel::ChannelImpl : public internal::ChannelReader { |
| public: |
| // Mirror methods of Channel, see ipc_channel.h for description. |
| ChannelImpl(const IPC::ChannelHandle& channel_handle, |
| Mode mode, |
| Listener* listener); |
| virtual ~ChannelImpl(); |
| |
| // Channel implementation. |
| bool Connect(); |
| void Close(); |
| bool Send(Message* message); |
| |
| // Posted to the main thread by ReaderThreadRunner. |
| void DidRecvMsg(scoped_ptr<MessageContents> contents); |
| void ReadDidFail(); |
| |
| private: |
| class ReaderThreadRunner; |
| |
| bool CreatePipe(const IPC::ChannelHandle& channel_handle); |
| bool ProcessOutgoingMessages(); |
| |
| // ChannelReader implementation. |
| virtual ReadState ReadData(char* buffer, |
| int buffer_len, |
| int* bytes_read) OVERRIDE; |
| virtual bool WillDispatchInputMessage(Message* msg) OVERRIDE; |
| virtual bool DidEmptyInputBuffers() OVERRIDE; |
| virtual void HandleInternalMessage(const Message& msg) OVERRIDE; |
| |
| Mode mode_; |
| bool waiting_connect_; |
| |
| // The pipe used for communication. |
| int pipe_; |
| |
| // The "name" of our pipe. On Windows this is the global identifier for |
| // the pipe. On POSIX it's used as a key in a local map of file descriptors. |
| // For NaCl, we don't actually support looking up file descriptors by name, |
| // and it's only used for debug information. |
| std::string pipe_name_; |
| |
| // We use a thread for reading, so that we can simply block on reading and |
| // post the received data back to the main thread to be properly interleaved |
| // with other tasks in the MessagePump. |
| // |
| // imc_recvmsg supports non-blocking reads, but there's no easy way to be |
| // informed when a write or read can be done without blocking (this is handled |
| // by libevent in Posix). |
| scoped_ptr<ReaderThreadRunner> reader_thread_runner_; |
| scoped_ptr<base::DelegateSimpleThread> reader_thread_; |
| |
| // IPC::ChannelReader expects to be able to call ReadData on us to |
| // synchronously read data waiting in the pipe's buffer without blocking. |
| // Since we can't do that (see 1 and 2 above), the reader thread does blocking |
| // reads and posts the data over to the main thread in MessageContents. Each |
| // MessageContents object is the result of one call to "imc_recvmsg". |
| // DidRecvMsg breaks the MessageContents out in to the data and the file |
| // descriptors, and puts them on these two queues. |
| // TODO(dmichael): There's probably a more efficient way to emulate this with |
| // a circular buffer or something, so we don't have to do so |
| // many heap allocations. But it maybe isn't worth |
| // the trouble given that we probably want to implement 1 and |
| // 2 above in NaCl eventually. |
| // When ReadData is called, it pulls the bytes out of this queue in order. |
| std::deque<linked_ptr<std::vector<char> > > read_queue_; |
| // Queue of file descriptors extracted from imc_recvmsg messages. |
| // NOTE: The implementation assumes underlying storage here is contiguous, so |
| // don't change to something like std::deque<> without changing the |
| // implementation! |
| std::vector<int> input_fds_; |
| |
| // This queue is used when a message is sent prior to Connect having been |
| // called. Normally after we're connected, the queue is empty. |
| std::deque<linked_ptr<Message> > output_queue_; |
| |
| base::WeakPtrFactory<ChannelImpl> weak_ptr_factory_; |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(ChannelImpl); |
| }; |
| |
| } // namespace IPC |
| |
| #endif // IPC_IPC_CHANNEL_NACL_H_ |