physicalsocketserver.cxx

由GOOGLE的JINGLE项目中移植的网络库

    return 0;
  }

  virtual void OnPreEvent(uint32 ff) {
    WSAResetEvent(hev_);
  }

  virtual void OnEvent(uint32 ff, int err) {
  }

  virtual WSAEVENT GetWSAEvent() {
    return hev_;
  }

  virtual SOCKET GetSocket() {
    return INVALID_SOCKET;
  }

  virtual bool CheckSignalClose() { return false; }

private:
  PhysicalSocketServer* ss_;
  WSAEVENT hev_;
};

class SocketDispatcher : public Dispatcher, public PhysicalSocket {
public:
  static int next_id_;
  int id_;
  bool signal_close_;
  int signal_err_;

  SocketDispatcher(PhysicalSocketServer* ss) : PhysicalSocket(ss), id_(0), signal_close_(false) {
  }
  SocketDispatcher(SOCKET s, PhysicalSocketServer* ss) : PhysicalSocket(ss, s), id_(0), signal_close_(false) {
  }

  virtual ~SocketDispatcher() {
    Close();
  }

  bool Initialize() {
    assert(s_ != INVALID_SOCKET);
    // Must be a non-blocking
    u_long argp = 1;
    ioctlsocket(s_, FIONBIO, &argp);
    ss_->Add(this);
    return true;
  }
 
  virtual bool Create(int type) {
    // Create socket
    if (!PhysicalSocket::Create(type))
      return false;

    if (!Initialize())
      return false;

    do { id_ = ++next_id_; } while (id_ == 0);
    return true;
  }

  virtual int Close() {
    if (s_ == INVALID_SOCKET)
      return 0;

    id_ = 0;
    signal_close_ = false;
    ss_->Remove(this);
    return PhysicalSocket::Close();
  }

  virtual uint32 GetRequestedEvents() {
    return enabled_events_;
  }

  virtual void OnPreEvent(uint32 ff) {
    if ((ff & kfConnect) != 0)
      state_ = CS_CONNECTED;
  }

  virtual void OnEvent(uint32 ff, int err) {
    int cache_id = id_;
    if ((ff & kfRead) != 0) {
      enabled_events_ &= ~kfRead;
      SignalReadEvent(this);
    }
    if (((ff & kfWrite) != 0) && (id_ == cache_id)) {
      enabled_events_ &= ~kfWrite;
      SignalWriteEvent(this);
    }
    if (((ff & kfConnect) != 0) && (id_ == cache_id)) {
      if (ff != kfConnect)
      enabled_events_ &= ~kfConnect;
      SignalConnectEvent(this);
    }
    if (((ff & kfClose) != 0) && (id_ == cache_id)) {      
      signal_close_ = true;
      signal_err_ = err;
    }
  }

  virtual WSAEVENT GetWSAEvent() {
    return WSA_INVALID_EVENT;
  }

  virtual SOCKET GetSocket() {
    return s_;
  }

  virtual bool CheckSignalClose() {
    if (!signal_close_)
      return false;

    char ch;
    if (recv(s_, &ch, 1, MSG_PEEK) > 0)
      return false;

    signal_close_ = false;
    SignalCloseEvent(this, signal_err_);
    return true;
  }
};

int SocketDispatcher::next_id_ = 0;


// Sets the value of a boolean value to false when signaled.
class Signaler : public EventDispatcher {
public:
  Signaler(PhysicalSocketServer* ss, bool* pf)
      : EventDispatcher(ss), pf_(pf) {
  }
  virtual ~Signaler() { }

  void OnEvent(uint32 ff, int err) {
    if (pf_)
      *pf_ = false;
  }

private:
  bool *pf_;
};

PhysicalSocketServer::PhysicalSocketServer() : fWait_(false),
  last_tick_tracked_(0), last_tick_dispatch_count_(0) {
  signal_wakeup_ = new Signaler(this, &fWait_);
}

PhysicalSocketServer::~PhysicalSocketServer() {
  delete signal_wakeup_;
}

void PhysicalSocketServer::WakeUp() {
  signal_wakeup_->Signal();
}

Socket* PhysicalSocketServer::CreateSocket(int type) {
  PhysicalSocket* socket = new PhysicalSocket(this);
  if (socket->Create(type)) {
    return socket;
  } else {
    delete socket;
    return 0;
  }
}

AsyncSocket* PhysicalSocketServer::CreateAsyncSocket(int type) {
  SocketDispatcher* dispatcher = new SocketDispatcher(this);
  if (dispatcher->Create(type)) {
    return dispatcher;
  } else {
    delete dispatcher;
    return 0;
  }
}

AsyncSocket* PhysicalSocketServer::WrapSocket(SOCKET s) {
  SocketDispatcher* dispatcher = new SocketDispatcher(s, this);
  if (dispatcher->Initialize()) {
    return dispatcher;
  } else {
    delete dispatcher;
    return 0;
  }
}

void PhysicalSocketServer::Add(Dispatcher *pdispatcher) {
  CritScope cs(&crit_);
  dispatchers_.push_back(pdispatcher);
}

void PhysicalSocketServer::Remove(Dispatcher *pdispatcher) {
  CritScope cs(&crit_);
  dispatchers_.erase(std::remove(dispatchers_.begin(), dispatchers_.end(), pdispatcher), dispatchers_.end());
}

bool PhysicalSocketServer::Wait(int cmsWait, bool process_io)
{
  int cmsTotal = cmsWait;
  int cmsElapsed = 0;
  uint32 msStart = GetMillisecondCount();

#if LOGGING
  if (last_tick_dispatch_count_ == 0) {
    last_tick_tracked_ = msStart;
  }
#endif

  WSAEVENT socket_ev = WSACreateEvent();
  
  fWait_ = true;
  while (fWait_) {
    std::vector<WSAEVENT> events;
    std::vector<Dispatcher *> event_owners;

    events.push_back(socket_ev);

    {
      CritScope cr(&crit_);
      for (size_t i = 0; i < dispatchers_.size(); ++i) {
        Dispatcher * disp = dispatchers_[i];
        if (!process_io && (disp != signal_wakeup_))
          continue;
        SOCKET s = disp->GetSocket();
        if (disp->CheckSignalClose()) {
          // We just signalled close, don't poll this socket
        } else if (s != INVALID_SOCKET) {
          WSAEventSelect(s, events[0], FlagsToEvents(disp->GetRequestedEvents()));
        } else {
          events.push_back(disp->GetWSAEvent());
          event_owners.push_back(disp);
        }
      }
    }

    // Which is shorter, the delay wait or the asked wait?

    int cmsNext;
    if (cmsWait == -1) {
      cmsNext = cmsWait;
    } else {
      cmsNext = cmsTotal - cmsElapsed;
      if (cmsNext < 0)
        cmsNext = 0;
    }

    // Wait for one of the events to signal
    DWORD dw = WSAWaitForMultipleEvents(static_cast<DWORD>(events.size()), &events[0], false, cmsNext, false);

#if 0  // LOGGING
    // we track this information purely for logging purposes.
    last_tick_dispatch_count_++;
    if (last_tick_dispatch_count_ >= 1000) {
      uint32 now = GetMillisecondCount();
      LOG(INFO) << "PhysicalSocketServer took " << TimeDiff(now, last_tick_tracked_) << "ms for 1000 events";

      // If we get more than 1000 events in a second, we are spinning badly
      // (normally it should take about 8-20 seconds).
      assert(TimeDiff(now, last_tick_tracked_) > 1000);
      
      last_tick_tracked_ = now;
      last_tick_dispatch_count_ = 0;
    }
#endif

    // Failed?
    // todo: need a better strategy than this!

    if (dw == WSA_WAIT_FAILED) {
      int error = WSAGetLastError();
      assert(false);
      WSACloseEvent(socket_ev);
      return false;
    }

    // Timeout?

    if (dw == WSA_WAIT_TIMEOUT) {
      WSACloseEvent(socket_ev);
      return true;
    }

    // Figure out which one it is and call it

    {
      CritScope cr(&crit_);
      int index = dw - WSA_WAIT_EVENT_0;
      if (index > 0) {
        --index; // The first event is the socket event
        event_owners[index]->OnPreEvent(0);
        event_owners[index]->OnEvent(0, 0);
      } else if (process_io) {
        for (size_t i = 0; i < dispatchers_.size(); ++i) {
          Dispatcher * disp = dispatchers_[i];
          SOCKET s = disp->GetSocket();
          if (s == INVALID_SOCKET)
            continue;

          WSANETWORKEVENTS wsaEvents;
          int err = WSAEnumNetworkEvents(s, events[0], &wsaEvents);
          if (err == 0) {
            /*
#if LOGGING
            {
              if ((wsaEvents.lNetworkEvents & FD_READ) && wsaEvents.iErrorCode[FD_READ_BIT] != 0) {
                LOG(WARNING) << "PhysicalSocketServer got FD_READ_BIT error " << wsaEvents.iErrorCode[FD_READ_BIT];
              }
              if ((wsaEvents.lNetworkEvents & FD_WRITE) && wsaEvents.iErrorCode[FD_WRITE_BIT] != 0) {
                LOG(WARNING) << "PhysicalSocketServer got FD_WRITE_BIT error " << wsaEvents.iErrorCode[FD_WRITE_BIT];
              }
              if ((wsaEvents.lNetworkEvents & FD_CONNECT) && wsaEvents.iErrorCode[FD_CONNECT_BIT] != 0) {
                LOG(WARNING) << "PhysicalSocketServer got FD_CONNECT_BIT error " << wsaEvents.iErrorCode[FD_CONNECT_BIT];
              }
              if ((wsaEvents.lNetworkEvents & FD_ACCEPT) && wsaEvents.iErrorCode[FD_ACCEPT_BIT] != 0) {
                LOG(WARNING) << "PhysicalSocketServer got FD_ACCEPT_BIT error " << wsaEvents.iErrorCode[FD_ACCEPT_BIT];
              }
              if ((wsaEvents.lNetworkEvents & FD_CLOSE) && wsaEvents.iErrorCode[FD_CLOSE_BIT] != 0) {
                LOG(WARNING) << "PhysicalSocketServer got FD_CLOSE_BIT error " << wsaEvents.iErrorCode[FD_CLOSE_BIT];
              }
            }
#endif
			*/
            uint32 ff = 0;
            int errcode = 0;
            if (wsaEvents.lNetworkEvents & FD_READ)
              ff |= kfRead;
            if (wsaEvents.lNetworkEvents & FD_WRITE)
              ff |= kfWrite;
            if (wsaEvents.lNetworkEvents & FD_CONNECT) {
              if (wsaEvents.iErrorCode[FD_CONNECT_BIT] == 0) {
                ff |= kfConnect;
              } else {
                // TODO: Decide whether we want to signal connect, but with an error code
                ff |= kfClose; 
                errcode = wsaEvents.iErrorCode[FD_CONNECT_BIT];
              }
            }
            if (wsaEvents.lNetworkEvents & FD_ACCEPT)
              ff |= kfRead;
            if (wsaEvents.lNetworkEvents & FD_CLOSE) {
              ff |= kfClose;
              errcode = wsaEvents.iErrorCode[FD_CLOSE_BIT];
            }
            if (ff != 0) {
              disp->OnPreEvent(ff);
              disp->OnEvent(ff, errcode);
            }
          }
        }
      }

      // Reset the network event until new activity occurs
      WSAResetEvent(socket_ev);
    }

    // Break?

    if (!fWait_)
      break;
    cmsElapsed = GetMillisecondCount() - msStart;
    if (cmsWait != -1) {
      if (cmsElapsed >= cmsWait)
        break;
    }
  }
  
  // Done
  
  WSACloseEvent(socket_ev);
  return true;
}

} // namespace cricket