Esempio n. 1
0
  /** (synchronous version) */
  public String requestWaitAndReceive(String requestData) {
    int recvTimeout = getRequestTimeout();

    final String[] response = new String[1];

    synchronized (response) {
      queueRequest(
          requestData,
          recvTimeout,
          new H1<String>() {

            @Override
            public void handle(String value) {
              synchronized (response) {
                response[0] = value;

                response.notify();
              }
            }
          });

      // wait for a while or until notified when a response is received
      Threads.waitOnSync(response, recvTimeout);
    }

    return response[0];
  }
Esempio n. 2
0
  /** The main thread. */
  private void begin() {
    while (!_shutdown) {
      // only need to set the thread state once here
      _threadStateHandler.handle();

      try {
        connectAndRead();

      } catch (Exception exc) {
        if (_shutdown) {
          // thread can gracefully exit
          return;
        }

        if (_recentlyConnected) _backoffTime = MIN_CONNETION_GAP;
        else {
          _backoffTime = Math.min(_backoffTime * 2, MAX_BACKOFF);
          _backoffTime = Math.max(MIN_CONNETION_GAP, _backoffTime);
        }

        long timeDiff = (System.nanoTime() - _lastSuccessfulConnection) / 1000000;
        if (timeDiff > _timeout) {
          // reset the timestamp
          _lastSuccessfulConnection = System.nanoTime();

          _callbackHandler.handle(_timeoutCallback, _callbackErrorHandler);
        }

        _recentlyConnected = false;
      }

      Threads.wait(_lock, _backoffTime);
    } // (while)
  }
Esempio n. 3
0
  /** Synchronous version. */
  public String waitAndReceive() {
    int recvTimeout = getRequestTimeout();
    QueuedRequest request = new QueuedRequest(null, null, recvTimeout, null);

    synchronized (request) {
      queueRequest(null, _requestTimeout, null);

      // wait for a while or until notified when a response is received
      Threads.waitOnSync(request, recvTimeout);
    }

    return request.response;
  }
Esempio n. 4
0
  /** (thread entry-point) */
  private void unicastReceiverThreadMain() {
    while (_enabled) {
      MulticastSocket socket = null;

      try {
        synchronized (_lock) {
          // clear flag regardless
          _recycleSender = false;
        }

        socket = createMulticastSocket(s_sendSocketLabel, s_interface, 0);

        // make sure a recycle request hasn't since occurred
        synchronized (_lock) {
          if (_recycleSender) {
            Stream.safeClose(socket);
            continue;
          }

          _sendSocket = socket;
        }

        while (_enabled) {
          DatagramPacket dp = UDPPacketRecycleQueue.instance().getReadyToUsePacket();

          try {
            socket.receive(dp);

          } catch (Exception exc) {
            UDPPacketRecycleQueue.instance().returnPacket(dp);

            throw exc;
          }

          if (dp.getAddress().isMulticastAddress()) {
            s_multicastInData.addAndGet(dp.getLength());
            s_multicastInOps.incrementAndGet();
          } else {
            s_unicastInData.addAndGet(dp.getLength());
            s_unicastInOps.incrementAndGet();
          }

          enqueueForProcessing(dp, s_sendSocketLabel);
        } // (inner while)

      } catch (Exception exc) {
        boolean wasClosed = (socket != null && socket.isClosed());

        // clean up regardless
        Stream.safeClose(socket);

        synchronized (_lock) {
          if (!_enabled) break;

          if (wasClosed)
            _logger.info(
                s_sendSocketLabel + " was signalled to gracefully close. Will reinitialise...");
          else _logger.warn(s_sendSocketLabel + " receive failed; will reinitialise...", exc);

          // stagger retry
          Threads.waitOnSync(_lock, 333);
        }
      }
    } // (outer while)

    _logger.info("This thread has run to completion.");
  }
Esempio n. 5
0
  /** (thread entry-point) */
  private void multicastReceiverThreadMain() {
    while (_enabled) {
      MulticastSocket socket = null;

      try {
        synchronized (_lock) {
          // clear flag regardless
          _recycleReceiver = false;
        }

        socket = createMulticastSocket(s_receiveSocketlabel, s_interface, MDNS_PORT);

        synchronized (_lock) {
          // make sure not flagged since reset
          if (_recycleReceiver) {
            Stream.safeClose(socket);
            continue;
          }

          _receiveSocket = socket;
        }

        while (_enabled) {
          DatagramPacket dp = UDPPacketRecycleQueue.instance().getReadyToUsePacket();

          // ('returnPacket' will be called in 'catch' or later after use in thread-pool)

          try {
            socket.receive(dp);

          } catch (Exception exc) {
            UDPPacketRecycleQueue.instance().returnPacket(dp);

            throw exc;
          }

          InetAddress recvAddr = dp.getAddress();

          if (recvAddr.isMulticastAddress()) {
            s_multicastInData.addAndGet(dp.getLength());
            s_multicastInOps.incrementAndGet();
          } else {
            s_unicastInData.addAndGet(dp.getLength());
            s_unicastInOps.incrementAndGet();
          }

          // check whether it's external i.e. completely different IP address
          // (local multicasting would almost always be reliable)

          MulticastSocket otherLocal = _sendSocket;
          boolean isLocal = (otherLocal != null && recvAddr.equals(otherLocal.getLocalAddress()));

          // update counter which is used to detect silence
          if (!isLocal) _lastExternalMulticastPacket = System.nanoTime();

          enqueueForProcessing(dp, s_receiveSocketlabel);
        } // (inner while)

      } catch (Exception exc) {
        // (timeouts and general IO problems)

        // clean up regardless
        Stream.safeClose(socket);

        synchronized (_lock) {
          if (!_enabled) break;

          if (_recycleReceiver)
            _logger.info(s_receiveSocketlabel + " was gracefully closed. Will reinitialise...");
          else
            _logger.warn(
                s_receiveSocketlabel
                    + " receive failed; this may be a transitional condition. Will reinitialise... message was '"
                    + exc.toString()
                    + "'");

          // set flag
          _recycleSender = true;
          // "signal" other thread
          Stream.safeClose(_sendSocket);

          // stagger retry
          Threads.waitOnSync(_lock, 333);
        }
      }
    } // (outer while)

    _logger.info("This thread has run to completion.");
  } // (method)