How to use

getResult

method

in

org.jgroups.util.Promise

/**
 * Returns the result, but never throws a TimeoutException; returns null instead.
 * @param timeout in ms
 * @return T
 */
public T getResult(long timeout) {
  return getResult(timeout, false);
}

public boolean waitForAllAcks() {
  if(missing_acks.isEmpty())
    return true;
  Boolean result=all_acks_received.getResult();
  return result != null && result;
}

protected void start(String host, int port, String cluster_name, boolean nio) {
  try {
    stub=new RouterStub(null, 0, InetAddress.getByName(host), port, nio, null);
    stub.connect();
    stub.getMembers(cluster_name, this);
    promise.getResult(5000);
  }
  catch(Exception ex) {
    ex.printStackTrace();
    stub.destroy();
  }
}

if(!ack_mode || !running || flushing)
  break;
Long ack=ack_promise.getResult(500);
if((Objects.equals(ack, seqno)) || !forward_table.containsKey(seqno))
  break;

/**
 * Sends a leave request to coord and blocks until a leave response has been received, or the leave timeout has elapsed
 */
protected void sendLeaveReqTo(Address coord) {
  leave_promise.reset();
  leaving=true;
  log.trace("%s: sending LEAVE request to %s", gms.local_addr, coord);
  long start=System.currentTimeMillis();
  sendLeaveMessage(coord, gms.local_addr);
  Boolean result=leave_promise.getResult(gms.leave_timeout);
  long time=System.currentTimeMillis()-start;
  if(result != null)
    log.trace("%s: got LEAVE response from %s in %d ms", gms.local_addr, coord, time);
  else
    log.trace("%s: timed out waiting for LEAVE response from %s (after %d ms)", gms.local_addr, coord, time);
}

Bits.writeLong(start, req_buf, 3);
tp.send(target, req_buf, 0, req_buf.length);
promise.getResult(0);
long time=time(use_ms)-start;
rtt.add(time);

protected boolean installViewIfValidJoinRsp(final Promise<JoinRsp> join_promise, boolean block_for_rsp) {
  boolean success=false;
  JoinRsp rsp=null;
  try {
    if(join_promise.hasResult())
      rsp=join_promise.getResult(1, true);
    else if(block_for_rsp)
      rsp=join_promise.getResult(gms.join_timeout, true);
    return success=rsp != null && isJoinResponseValid(rsp) && installView(rsp.getView(), rsp.getDigest());
  }
  finally {
    if(success)
      gms.sendViewAck(rsp.getView().getCreator());
  }
}

long start=System.currentTimeMillis();
down(new Event(Event.GET_STATE, state_info));
StateTransferResult result=state_promise.getResult(state_info.timeout);

ack_promise.reset();
down_prot.down(forward_msg);
Long ack=ack_promise.getResult(500);
if((Objects.equals(ack, key)) || !forward_table.containsKey(key))
  break;

/**
 Attempts to obtain the ping_addr first from the cache, then by unicasting q request to {@code mbr},
 then by multicasting a request to all members.
 */
protected IpAddress fetchPingAddress(final Address mbr) {
  IpAddress ret;
  if(mbr == null)
    return null;
  // 1. Try to get the server socket address from the cache
  if((ret=cache.get(mbr)) != null)
    return ret;
  if(!isPingerThreadRunning()) return null;
  // 2. Try to get the server socket address from mbr (or all, as fallback)
  ping_addr_promise.reset();
  for(Address dest: Arrays.asList(mbr, null)) {
    Message msg=new Message(dest).setFlag(Message.Flag.INTERNAL)
     .putHeader(this.id, new FdHeader(FdHeader.WHO_HAS_SOCK, mbr));
    down_prot.down(msg);
    if((ret=ping_addr_promise.getResult(500)) != null)
      return ret;
    if(!isPingerThreadRunning()) return null;
  }
  return null;
}

/**
 * Determines coordinator C. If C is null and we are the first member, return. Else loop: send GET_CACHE message
 * to coordinator and wait for GET_CACHE_RSP response. Loop until valid response has been received.
 */
protected void getCacheFromCoordinator() {
  Address coord;
  int attempts=num_tries;
  get_cache_promise.reset();
  while(attempts > 0 && isPingerThreadRunning()) {
    if((coord=determineCoordinator()) != null) {
      if(coord.equals(local_addr)) { // we are the first member --> empty cache
        return;
      }
      Message msg=new Message(coord).setFlag(Message.Flag.INTERNAL)
       .putHeader(this.id, new FdHeader(FdHeader.GET_CACHE));
      down_prot.down(msg);
      Map<Address,IpAddress> result=get_cache_promise.getResult(get_cache_timeout);
      if(result != null) {
        cache.addAll(result);
        log.trace("%s: got cache from %s: cache is %s", local_addr, coord, cache);
        return;
      }
    }
    --attempts;
  }
}

ack_promise.reset();
down_prot.down(forward_msg);
Long ack=ack_promise.getResult(500);
if((Objects.equals(ack, key)) || !forward_table.containsKey(key))
  break;

/**
 * Returns the result, but never throws a TimeoutException; returns null instead.
 * @param timeout in ms
 * @return T
 */
public T getResult(long timeout) {
  return getResult(timeout, false);
}

public boolean waitForAllAcks() {
  if(missing_acks.isEmpty())
    return true;
  Boolean result=all_acks_received.getResult();
  return result != null && result;
}

public boolean waitForAllAcks() {
  if(missing_acks.size() == 0)
    return true;
  Object result=all_acks_received.getResult();
  return result != null && result instanceof Boolean && ((Boolean)result).booleanValue();
}

/**
 * Returns a list of PingRsp pairs.
 */
Vector findInitialMembers() {
  PingRsp tmp=new PingRsp(local_addr, local_addr, true);
  find_promise.reset();
  down_prot.down(Event.FIND_INITIAL_MBRS_EVT);
  Vector retval=(Vector)find_promise.getResult(0); // wait indefinitely until response is received
  if(retval != null && is_coord && local_addr != null && !retval.contains(tmp))
    retval.add(tmp);
  return retval;
}

protected void start(String host, int port, String cluster_name, boolean nio) {
  try {
    stub=new RouterStub(null, 0, InetAddress.getByName(host), port, nio, null);
    stub.connect();
    stub.getMembers(cluster_name, this);
    promise.getResult(5000);
  }
  catch(Exception ex) {
    ex.printStackTrace();
    stub.destroy();
  }
}

/**
 * Sends a leave request to coord and blocks until a leave response has been received, or the leave timeout has elapsed
 */
protected void sendLeaveReqTo(Address coord) {
  leave_promise.reset();
  leaving=true;
  log.trace("%s: sending LEAVE request to %s", gms.local_addr, coord);
  long start=System.currentTimeMillis();
  sendLeaveMessage(coord, gms.local_addr);
  Boolean result=leave_promise.getResult(gms.leave_timeout);
  long time=System.currentTimeMillis()-start;
  if(result != null)
    log.trace("%s: got LEAVE response from %s in %d ms", gms.local_addr, coord, time);
  else
    log.trace("%s: timed out waiting for LEAVE response from %s (after %d ms)", gms.local_addr, coord, time);
}

protected boolean installViewIfValidJoinRsp(final Promise<JoinRsp> join_promise, boolean block_for_rsp) {
  boolean success=false;
  JoinRsp rsp=null;
  try {
    if(join_promise.hasResult())
      rsp=join_promise.getResult(1, true);
    else if(block_for_rsp)
      rsp=join_promise.getResult(gms.join_timeout, true);
    return success=rsp != null && isJoinResponseValid(rsp) && installView(rsp.getView(), rsp.getDigest());
  }
  finally {
    if(success)
      gms.sendViewAck(rsp.getView().getCreator());
  }
}

  public void run() {
    Message msg;
    int num_missed_hbs=0;
    dest=getHeartbeatDest();
    if(dest == null) {
      if(log.isWarnEnabled()) log.warn("heartbeat destination was null, will not send ARE_YOU_ALIVE message");
      return;
    }
    if(log.isInfoEnabled())
      log.info("sending ARE_YOU_ALIVE message to " + dest + ", counters are\n" + printCounters());
    promise.reset();
    msg=new Message(dest);
    msg.putHeader(name, new FdHeader(FdHeader.ARE_YOU_ALIVE));
    down_prot.down(new Event(Event.MSG, msg));
    promise.getResult(timeout);
    num_missed_hbs=incrementCounter(dest);
    if(num_missed_hbs >= max_missed_hbs) {
      if(log.isInfoEnabled())
        log.info("missed " + num_missed_hbs + " from " + dest + ", suspecting member");
      up_prot.up(new Event(Event.SUSPECT, dest));
    }
  }
}