text: /*
   * libjingle
   * Copyright 2004--2006, Google Inc.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   *  1. Redistributions of source code must retain the above copyright notice,
   *     this list of conditions and the following disclaimer.
   *  2. Redistributions in binary form must reproduce the above copyright notice,
   *     this list of conditions and the following disclaimer in the documentation
   *     and/or other materials provided with the distribution.
   *  3. The name of the author may not be used to endorse or promote products
   *     derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
   * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
   * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
   * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifndef __PSEUDOTCPCHANNEL_H__
  #define __PSEUDOTCPCHANNEL_H__
  
  #include "talk/base/criticalsection.h"
  #include "talk/base/messagequeue.h"
  #include "talk/base/stream.h"
  #include "talk/p2p/base/pseudotcp.h"
  #include "talk/p2p/base/session.h"
  
  namespace talk_base {
  class Thread;
  }
  
  namespace cricket {
  
  class Candidate;
  class TransportChannel;
  
  ///////////////////////////////////////////////////////////////////////////////
  // PseudoTcpChannel
  // Note: The PseudoTcpChannel must persist until both of:
  // 1) The StreamInterface provided via GetStream has been closed.
  //    This is tracked via non-null stream_.
  // 2) The PseudoTcp session has completed.
  //    This is tracked via non-null worker_thread_.  When PseudoTcp is done,
  //    the TransportChannel is signalled to tear-down.  Once the channel is
  //    torn down, the worker thread is purged.
  // These indicators are checked by CheckDestroy, invoked whenever one of them
  // changes.
  ///////////////////////////////////////////////////////////////////////////////
  // PseudoTcpChannel::GetStream
  // Note: The stream pointer returned by GetStream is owned by the caller.
  // They can close & immediately delete the stream while PseudoTcpChannel still
  // has cleanup work to do.  They can also close the stream but not delete it
  // until long after PseudoTcpChannel has finished.  We must cope with both.
  ///////////////////////////////////////////////////////////////////////////////
  
  class PseudoTcpChannel
    : public IPseudoTcpNotify,
      public talk_base::MessageHandler,
      public sigslot::has_slots<> {
  public:
    // Signal thread methods
    PseudoTcpChannel(talk_base::Thread* stream_thread,
                     Session* session);
  
    bool Connect(const std::string& content_name,
                 const std::string& channel_name);
    talk_base::StreamInterface* GetStream();
  
    sigslot::signal1<PseudoTcpChannel*> SignalChannelClosed;
  
    // Call this when the Session used to create this channel is being torn
    // down, to ensure that things get cleaned up properly.
    void OnSessionTerminate(Session* session);
  
    // See the PseudoTcp class for available options.
    void GetOption(PseudoTcp::Option opt, int* value);
    void SetOption(PseudoTcp::Option opt, int value);
  
  private:
    class InternalStream;
    friend class InternalStream;
  
    virtual ~PseudoTcpChannel();
  
    // Stream thread methods
    talk_base::StreamState GetState() const;
    talk_base::StreamResult Read(void* buffer, size_t buffer_len,
                                 size_t* read, int* error);
    talk_base::StreamResult Write(const void* data, size_t data_len,
                                  size_t* written, int* error);
    void Close();
  
    // Multi-thread methods
    void OnMessage(talk_base::Message* pmsg);
    void AdjustClock(bool clear = true);
    void CheckDestroy();
  
    // Signal thread methods
    void OnChannelDestroyed(TransportChannel* channel);
  
    // Worker thread methods
    void OnChannelWritableState(TransportChannel* channel);
    void OnChannelRead(TransportChannel* channel, const char* data, size_t size);
    void OnChannelConnectionChanged(TransportChannel* channel,
                                    const Candidate& candidate);
  
    virtual void OnTcpOpen(PseudoTcp* ptcp);
    virtual void OnTcpReadable(PseudoTcp* ptcp);
    virtual void OnTcpWriteable(PseudoTcp* ptcp);
    virtual void OnTcpClosed(PseudoTcp* ptcp, uint32 nError);
    virtual IPseudoTcpNotify::WriteResult TcpWritePacket(PseudoTcp* tcp,
                                                         const char* buffer,
                                                         size_t len);
  
    talk_base::Thread* signal_thread_, * worker_thread_, * stream_thread_;
    Session* session_;
    TransportChannel* channel_;
    std::string content_name_;
    std::string channel_name_;
    PseudoTcp* tcp_;
    InternalStream* stream_;
    bool stream_readable_, pending_read_event_;
    bool ready_to_connect_;
    mutable talk_base::CriticalSection cs_;
  };
  
  ///////////////////////////////////////////////////////////////////////////////
  
  } // namespace cricket
  
  #endif // __PSEUDOTCPCHANNEL_H__
  