Beispiel #1
0
  /**
   * Check whether the hashmap contains an entry e for <code>sender</code> (create if not). If
   * e.received_msgs is null and <code>first</code> is true: create a new AckReceiverWindow(seqno)
   * and add message. Set e.received_msgs to the new window. Else just add the message.
   */
  protected void handleDataReceived(
      Address sender, long seqno, short conn_id, boolean first, Message msg, Event evt) {
    if (log.isTraceEnabled()) {
      StringBuilder sb = new StringBuilder();
      sb.append(local_addr).append(" <-- DATA(").append(sender).append(": #").append(seqno);
      if (conn_id != 0) sb.append(", conn_id=").append(conn_id);
      if (first) sb.append(", first");
      sb.append(')');
      log.trace(sb);
    }

    ReceiverEntry entry = getReceiverEntry(sender, seqno, first, conn_id);
    if (entry == null) return;
    if (conn_expiry_timeout > 0) entry.update();
    Table<Message> win = entry.received_msgs;
    boolean added = win.add(seqno, msg); // win is guaranteed to be non-null if we get here
    num_msgs_received++;

    if (added) {
      int len = msg.getLength();
      if (len > 0 && entry.incrementStable(len))
        sendStableMessage(
            sender, entry.recv_conn_id, win.getHighestDelivered(), win.getHighestReceived());
    }

    // An OOB message is passed up immediately. Later, when remove() is called, we discard it. This
    // affects ordering !
    // http://jira.jboss.com/jira/browse/JGRP-377
    if (msg.isFlagSet(Message.OOB) && added) {
      try {
        up_prot.up(evt);
      } catch (Throwable t) {
        log.error("couldn't deliver OOB message " + msg, t);
      }
    }

    final AtomicBoolean processing = win.getProcessing();
    if (!processing.compareAndSet(false, true)) {
      return;
    }

    // Try to remove as many messages as possible and pass them up.
    // Prevents concurrent passing up of messages by different threads
    // (http://jira.jboss.com/jira/browse/JGRP-198);
    // this is all the more important once we have a concurrent stack
    // (http://jira.jboss.com/jira/browse/JGRP-181),
    // where lots of threads can come up to this point concurrently, but only 1 is allowed to pass
    // at a time
    // We *can* deliver messages from *different* senders concurrently, e.g. reception of P1, Q1,
    // P2, Q2 can result in
    // delivery of P1, Q1, Q2, P2: FIFO (implemented by UNICAST) says messages need to be delivered
    // only in the
    // order in which they were sent by their senders
    boolean released_processing = false;
    try {
      while (true) {
        List<Message> msgs =
            win.removeMany(processing, true, max_msg_batch_size); // remove my own messages
        if (msgs == null || msgs.isEmpty()) {
          released_processing = true;
          return;
        }

        for (Message m : msgs) {
          // discard OOB msg: it has already been delivered
          // (http://jira.jboss.com/jira/browse/JGRP-377)
          if (m.isFlagSet(Message.OOB)) continue;
          try {
            up_prot.up(new Event(Event.MSG, m));
          } catch (Throwable t) {
            log.error("couldn't deliver message " + m, t);
          }
        }
      }
    } finally {
      // processing is always set in win.remove(processing) above and never here ! This code is just
      // a
      // 2nd line of defense should there be an exception before win.remove(processing) sets
      // processing
      if (!released_processing) processing.set(false);
    }
  }