POCO连接被卡住
POCO connection gets stuck

我正在使用POCO反应堆模式来处理传入的TCP连接。 连接可能需要几秒钟到几分钟，具体取决于请求类型，如下所示：

  try{
    ServerSocket serverSocket(port);
    reactor = new SocketReactor();
    ParallelSocketAcceptor<BFSTcpServiceHandler,SocketReactor> acceptor(serverSocket, *reactor);
    //Start Reactor
    reactor->run();
  }catch(Exception&e){
    LOG(ERROR)<<"ERROR in initializing TCPServer:"<<e.message();
    return;
  }

这是处理程序：

BFSTcpServiceHandler::BFSTcpServiceHandler(StreamSocket& _socket,
    SocketReactor& _reactor): socket(_socket),reactor(_reactor) {
  //Set Keeep Alive for socket
  socket.setKeepAlive(false);

  //Register Callbacks
  reactor.addEventHandler(socket, NObserver<BFSTcpServiceHandler,
    ReadableNotification>(*this, &BFSTcpServiceHandler::onReadable));
  /*reactor.addEventHandler(socket, NObserver<BFSTcpServiceHandler,
    WritableNotification>(*this, &BFSTcpServiceHandler::onWriteable));*/
  reactor.addEventHandler(socket, NObserver<BFSTcpServiceHandler,
    ShutdownNotification>(*this, &BFSTcpServiceHandler::onShutdown));
  reactor.addEventHandler(socket, NObserver<BFSTcpServiceHandler,
    ErrorNotification>(*this, &BFSTcpServiceHandler::onError));
  reactor.addEventHandler(socket, NObserver<BFSTcpServiceHandler,
    TimeoutNotification>(*this, &BFSTcpServiceHandler::onTimeout));
  /*reactor.addEventHandler(socket, NObserver<BFSTcpServiceHandler,
    IdleNotification>(*this, &BFSTcpServiceHandler::onIdle));*/
}

BFSTcpServiceHandler::~BFSTcpServiceHandler() {
  //Unregister Callbacks
  reactor.removeEventHandler(socket, NObserver<BFSTcpServiceHandler,
    ReadableNotification>(*this, &BFSTcpServiceHandler::onReadable));
    ...
  //Close socket
  try {
    socket.close();
  }catch(...){}
}

void BFSTcpServiceHandler::onReadable(
    const Poco::AutoPtr<Poco::Net::ReadableNotification>& pNf) {
  //LOG(ERROR)<<"onReadable:"<<socket.peerAddress().toString();
  try{
   //Read and process request
  } catch(Exception &e){
    LOG(ERROR)<<"Error in reading request:"<<e.message();
    delete this;
  }
  //So after a connection is served just close it!
  delete this;
}

void BFSTcpServiceHandler::onShutdown(
    const Poco::AutoPtr<Poco::Net::ShutdownNotification>& pNf) {
  LOG(ERROR)<<"onShutdown:"<<socket.peerAddress().toString();

  //Call destructor of this class
  delete this;
}

void BFSTcpServiceHandler::onWriteable(
    const Poco::AutoPtr<Poco::Net::WritableNotification>& pNf) {
  static bool once = true;
  if(once) {
    LOG(ERROR)<<"onWritable:"<<socket.peerAddress().toString()<<" keepAlive?"<<socket.getKeepAlive()<<" isBlocking?"<<socket.getBlocking()<<" noDeley?"<<socket.getNoDelay();
    once = false;
  }
}

void BFSTcpServiceHandler::onTimeout(
    const Poco::AutoPtr<Poco::Net::TimeoutNotification>& pNf) {
  LOG(ERROR)<<"\nTIMEOUT! onTimeout:"<<socket.peerAddress().toString();
}

void BFSTcpServiceHandler::onError(
    const Poco::AutoPtr<Poco::Net::ErrorNotification>& pNf) {
  LOG(ERROR)<<"\nERROR! onError:"<<socket.peerAddress().toString();
}

void BFSTcpServiceHandler::onIdle(
    const Poco::AutoPtr<Poco::Net::IdleNotification>& pNf) {
  LOG(ERROR)<<"\nIDLE! onIdle:"<<socket.peerAddress().toString();
}

代码工作正常； 但是，过了一会儿它卡住了，这意味着服务器确实接受了连接，但是根本不再调用onReadable。 例如，卡住后，我可以远程登录到服务器，但是当我发送数据时，onReadable不会被触发。 使用netstat，我意识到一些数据被保留在RCV_QEUEUE中，而且反应堆不会触发onReadable事件。

我认为这是由于达到系统的连接/文件限制所致，但是当系统卡住时，实际上并没有打开多少连接。

任何意见或帮助表示赞赏。

谢谢，