Fix race condition in adding TimeoutClusterStateListener

Fixes elastic#2658

Author: imotov

src/main/java/org/elasticsearch/cluster/service/InternalClusterService.java

@@ -189,19 +189,19 @@ public void remove(LocalNodeMasterListener listener) {
  localNodeMasterListeners.remove(listener);
  }
 
- public void add(TimeValue timeout, final TimeoutClusterStateListener listener) {
+ public void add(final TimeValue timeout, final TimeoutClusterStateListener listener) {
  if (lifecycle.stoppedOrClosed()) {
  listener.onClose();
  return;
  }
- NotifyTimeout notifyTimeout = new NotifyTimeout(listener, timeout);
- notifyTimeout.future = threadPool.schedule(timeout, ThreadPool.Names.GENERIC, notifyTimeout);
- onGoingTimeouts.add(notifyTimeout);
- clusterStateListeners.add(listener);
  // call the post added notification on the same event thread
  updateTasksExecutor.execute(new Runnable() {
  @Override
  public void run() {
+ NotifyTimeout notifyTimeout = new NotifyTimeout(listener, timeout);
+ notifyTimeout.future = threadPool.schedule(timeout, ThreadPool.Names.GENERIC, notifyTimeout);
+ onGoingTimeouts.add(notifyTimeout);
+ clusterStateListeners.add(listener);
  listener.postAdded();
  }
  });