Esempio n. 1
0
  /**
   * An event is to be sent down the stack. The layer may want to examine its type and perform some
   * action on it, depending on the event's type. If the event is a message MSG, then the layer may
   * need to add a header to it (or do nothing at all) before sending it down the stack using <code>
   * PassDown</code>. In case of a GET_ADDRESS event (which tries to retrieve the stack's address
   * from one of the bottom layers), the layer may need to send a new response event back up the
   * stack using <code>up_prot.up()</code>. The PING protocol is interested in several different
   * down events, Event.FIND_INITIAL_MBRS - sent by the GMS layer and expecting a GET_MBRS_OK
   * Event.TMP_VIEW and Event.VIEW_CHANGE - a view change event Event.BECOME_SERVER - called after
   * client has joined and is fully working group member Event.CONNECT, Event.DISCONNECT.
   */
  @SuppressWarnings("unchecked")
  public Object down(Event evt) {

    switch (evt.getType()) {
      case Event.FIND_INITIAL_MBRS: // sent by GMS layer
      case Event.FIND_ALL_VIEWS:
        // sends the GET_MBRS_REQ to all members, waits 'timeout' ms or until 'num_initial_members'
        // have been retrieved
        long start = System.currentTimeMillis();
        boolean find_all_views = evt.getType() == Event.FIND_ALL_VIEWS;
        Promise<JoinRsp> promise = (Promise<JoinRsp>) evt.getArg();
        List<PingData> rsps = find_all_views ? findAllViews(promise) : findInitialMembers(promise);
        long diff = System.currentTimeMillis() - start;
        if (log.isTraceEnabled())
          log.trace("discovery took " + diff + " ms: responses: " + Util.printPingData(rsps));
        return rsps;

      case Event.TMP_VIEW:
      case Event.VIEW_CHANGE:
        List<Address> tmp;
        view = (View) evt.getArg();
        if ((tmp = view.getMembers()) != null) {
          synchronized (members) {
            members.clear();
            members.addAll(tmp);
          }
        }
        current_coord = !members.isEmpty() ? members.get(0) : null;
        is_coord = current_coord != null && local_addr != null && current_coord.equals(local_addr);

        return down_prot.down(evt);

      case Event.BECOME_SERVER: // called after client has joined and is fully working group member
        down_prot.down(evt);
        is_server = true;
        return null;

      case Event.SET_LOCAL_ADDRESS:
        local_addr = (Address) evt.getArg();
        return down_prot.down(evt);

      case Event.CONNECT:
      case Event.CONNECT_WITH_STATE_TRANSFER:
      case Event.CONNECT_USE_FLUSH:
      case Event.CONNECT_WITH_STATE_TRANSFER_USE_FLUSH:
        is_leaving = false;
        group_addr = (String) evt.getArg();
        Object ret = down_prot.down(evt);
        handleConnect();
        return ret;

      case Event.DISCONNECT:
        is_leaving = true;
        handleDisconnect();
        return down_prot.down(evt);

      default:
        return down_prot.down(evt); // Pass on to the layer below us
    }
  }
Esempio n. 2
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  protected void handleViewChange(View v) {
    Address old_coord;
    List<Address> new_members = v.getMembers();
    boolean send_up_exception = false;

    this.view = v;
    synchronized (members) {
      old_coord = (!members.isEmpty() ? members.get(0) : null);
      members.clear();
      members.addAll(new_members);

      // this handles the case where a coord dies during a state transfer; prevents clients from
      // hanging forever
      // Note this only takes a coordinator crash into account, a getState(target, timeout), where
      // target is not
      // null is not handled ! (Usually we get the state from the coordinator)
      // http://jira.jboss.com/jira/browse/JGRP-148
      if (waiting_for_state_response && old_coord != null && !members.contains(old_coord))
        send_up_exception = true;
    }

    if (send_up_exception) {
      log.warn("%s: discovered that the state provider (%s) left", local_addr, old_coord);
      waiting_for_state_response = false;
      Exception ex = new EOFException("state provider " + old_coord + " left");
      up_prot.up(new Event(Event.GET_STATE_OK, new StateTransferResult(ex)));
      openBarrierAndResumeStable();
    }

    // remove non members from list of members requesting state
    state_requesters.retainAll(new_members);
  }
Esempio n. 3
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    public void run() {
      long end_time, wait_time;
      List<Request> requests = new LinkedList<Request>();
      while (Thread.currentThread().equals(thread) && !suspended) {
        try {
          boolean keepGoing = false;
          end_time = System.currentTimeMillis() + max_bundling_time;
          do {
            Request firstRequest =
                (Request)
                    queue.remove(INTERVAL); // throws a TimeoutException if it runs into timeout
            requests.add(firstRequest);
            if (!view_bundling) break;
            if (queue.size() > 0) {
              Request nextReq = (Request) queue.peek();
              keepGoing = view_bundling && firstRequest.canBeProcessedTogether(nextReq);
            } else {
              wait_time = end_time - System.currentTimeMillis();
              if (wait_time > 0)
                queue.waitUntilClosed(
                    wait_time); // misnomer: waits until element has been added or q closed
              keepGoing =
                  queue.size() > 0 && firstRequest.canBeProcessedTogether((Request) queue.peek());
            }
          } while (keepGoing && System.currentTimeMillis() < end_time);

          try {
            process(requests);
          } finally {
            requests.clear();
          }
        } catch (QueueClosedException e) {
          break;
        } catch (TimeoutException e) {
          break;
        } catch (Throwable catchall) {
          Util.sleep(50);
        }
      }
    }
Esempio n. 4
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  public Object down(Event evt) {
    switch (evt.getType()) {
      case Event.MSG: // Add UnicastHeader, add to AckSenderWindow and pass down
        Message msg = (Message) evt.getArg();
        Address dst = msg.getDest();

        /* only handle unicast messages */
        if (dst == null || msg.isFlagSet(Message.NO_RELIABILITY)) break;

        if (!started) {
          if (log.isTraceEnabled())
            log.trace("discarded message as start() has not yet been called, message: " + msg);
          return null;
        }

        SenderEntry entry = send_table.get(dst);
        if (entry == null) {
          entry = new SenderEntry(getNewConnectionId());
          SenderEntry existing = send_table.putIfAbsent(dst, entry);
          if (existing != null) entry = existing;
          else {
            if (log.isTraceEnabled())
              log.trace(
                  local_addr
                      + ": created connection to "
                      + dst
                      + " (conn_id="
                      + entry.send_conn_id
                      + ")");
            if (cache != null && !members.contains(dst)) cache.add(dst);
          }
        }

        long seqno = -2;
        short send_conn_id = -1;
        Unicast2Header hdr;

        entry.lock(); // threads will only sync if they access the same entry
        try {
          seqno = entry.sent_msgs_seqno;
          send_conn_id = entry.send_conn_id;
          hdr = Unicast2Header.createDataHeader(seqno, send_conn_id, seqno == DEFAULT_FIRST_SEQNO);
          msg.putHeader(this.id, hdr);
          entry.sent_msgs.addToMessages(
              seqno, msg); // add *including* UnicastHeader, adds to retransmitter
          entry.sent_msgs_seqno++;
          entry.update();
        } finally {
          entry.unlock();
        }

        if (log.isTraceEnabled()) {
          StringBuilder sb = new StringBuilder();
          sb.append(local_addr)
              .append(" --> DATA(")
              .append(dst)
              .append(": #")
              .append(seqno)
              .append(", conn_id=")
              .append(send_conn_id);
          if (hdr.first) sb.append(", first");
          sb.append(')');
          log.trace(sb);
        }

        try {
          down_prot.down(evt);
          num_msgs_sent++;
          num_bytes_sent += msg.getLength();
        } catch (Throwable t) {
          log.warn("failed sending the message", t);
        }
        return null; // we already passed the msg down

      case Event.VIEW_CHANGE: // remove connections to peers that are not members anymore !
        View view = (View) evt.getArg();
        List<Address> new_members = view.getMembers();
        Set<Address> non_members = new HashSet<Address>(send_table.keySet());
        non_members.addAll(recv_table.keySet());

        synchronized (members) {
          members.clear();
          if (new_members != null) members.addAll(new_members);
          non_members.removeAll(members);
          if (cache != null) {
            cache.removeAll(members);
          }
        }

        if (!non_members.isEmpty()) {
          if (log.isTraceEnabled()) log.trace("removing non members " + non_members);
          for (Address non_mbr : non_members) removeConnection(non_mbr);
        }
        break;

      case Event.SET_LOCAL_ADDRESS:
        local_addr = (Address) evt.getArg();
        break;
    }

    return down_prot.down(evt); // Pass on to the layer below us
  }
Esempio n. 5
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  @SuppressWarnings("unchecked")
  public Object down(Event evt) {
    switch (evt.getType()) {
      case Event.FIND_INITIAL_MBRS: // sent by GMS layer
        return findMembers(null, true, false); // triggered by JOIN process (ClientGmsImpl)

      case Event.FIND_MBRS:
        return findMembers(
            (List<Address>) evt.getArg(), false, false); // triggered by MERGE2/MERGE3

        // case Event.TMP_VIEW:
      case Event.VIEW_CHANGE:
        List<Address> tmp;
        View old_view = view;
        view = (View) evt.getArg();
        if ((tmp = view.getMembers()) != null) {
          synchronized (members) {
            members.clear();
            members.addAll(tmp);
          }
        }
        current_coord = !members.isEmpty() ? members.get(0) : null;
        is_coord = current_coord != null && local_addr != null && current_coord.equals(local_addr);
        Object retval = down_prot.down(evt);
        if (send_cache_on_join && !isDynamic() && is_coord) {
          List<Address> curr_mbrs, left_mbrs, new_mbrs;
          synchronized (members) {
            curr_mbrs = new ArrayList<>(members);
            left_mbrs = old_view != null ? Util.leftMembers(old_view.getMembers(), members) : null;
            new_mbrs = old_view != null ? Util.newMembers(old_view.getMembers(), members) : null;
          }
          startCacheDissemination(curr_mbrs, left_mbrs, new_mbrs); // separate task
        }
        return retval;

      case Event.BECOME_SERVER: // called after client has joined and is fully working group member
        down_prot.down(evt);
        is_server = true;
        return null;

      case Event.SET_LOCAL_ADDRESS:
        local_addr = (Address) evt.getArg();
        return down_prot.down(evt);

      case Event.CONNECT:
      case Event.CONNECT_WITH_STATE_TRANSFER:
      case Event.CONNECT_USE_FLUSH:
      case Event.CONNECT_WITH_STATE_TRANSFER_USE_FLUSH:
        is_leaving = false;
        cluster_name = (String) evt.getArg();
        Object ret = down_prot.down(evt);
        handleConnect();
        return ret;

      case Event.DISCONNECT:
        is_leaving = true;
        handleDisconnect();
        return down_prot.down(evt);

      default:
        return down_prot.down(evt); // Pass on to the layer below us
    }
  }