import org.apache.hadoop.yarn.server.resourcemanager.rmcontainer.RMContainerReservedEvent; //导入依赖的package包/类
private synchronized boolean commonReserve(SchedulerNode node,
    Priority priority, RMContainer rmContainer, Resource reservedResource) {
  try {
    rmContainer.handle(new RMContainerReservedEvent(rmContainer
        .getContainerId(), reservedResource, node.getNodeID(), priority));
  } catch (InvalidStateTransitionException e) {
    // We reach here could be caused by container already finished, return
    // false indicate it fails
    return false;
  }
  
  Map<NodeId, RMContainer> reservedContainers = 
      this.reservedContainers.get(priority);
  if (reservedContainers == null) {
    reservedContainers = new HashMap<NodeId, RMContainer>();
    this.reservedContainers.put(priority, reservedContainers);
  }
  reservedContainers.put(node.getNodeID(), rmContainer);

  if (LOG.isDebugEnabled()) {
    LOG.debug("Application attempt " + getApplicationAttemptId()
        + " reserved container " + rmContainer + " on node " + node
        + ". This attempt currently has " + reservedContainers.size()
        + " reserved containers at priority " + priority
        + "; currentReservation " + reservedResource);
  }
  
  return true;
}