content: /*
   * Copyright (C) 2012-2016 Markus Junginger, greenrobot (http://greenrobot.org)
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.greenrobot.eventbus;
  
  import android.os.Handler;
  import android.os.Looper;
  import android.os.Message;
  import android.os.SystemClock;
  
  public class HandlerPoster extends Handler implements Poster {
  
    private final PendingPostQueue queue;
    private final int maxMillisInsideHandleMessage;
    private final EventBus eventBus;
    private boolean handlerActive;
  
    public HandlerPoster(EventBus eventBus, Looper looper, int maxMillisInsideHandleMessage) {
      super(looper);
      this.eventBus = eventBus;
      this.maxMillisInsideHandleMessage = maxMillisInsideHandleMessage;
      queue = new PendingPostQueue();
    }
  
    public void enqueue(Subscription subscription, Object event) {
      PendingPost pendingPost = PendingPost.obtainPendingPost(subscription, event);
      synchronized (this) {
        queue.enqueue(pendingPost);
        if (!handlerActive) {
          handlerActive = true;
          if (!sendMessage(obtainMessage())) {
            throw new EventBusException("Could not send handler message");
          }
        }
      }
    }
  
    @Override
    public void handleMessage(Message msg) {
      boolean rescheduled = false;
      try {
        long started = SystemClock.uptimeMillis();
        while (true) {
          PendingPost pendingPost = queue.poll();
          if (pendingPost == null) {
            synchronized (this) {
              // Check again, this time in synchronized
              pendingPost = queue.poll();
              if (pendingPost == null) {
                handlerActive = false;
                return;
              }
            }
          }
          eventBus.invokeSubscriber(pendingPost);
          long timeInMethod = SystemClock.uptimeMillis() - started;
          if (timeInMethod >= maxMillisInsideHandleMessage) {
            if (!sendMessage(obtainMessage())) {
              throw new EventBusException("Could not send handler message");
            }
            rescheduled = true;
            return;
          }
        }
      } finally {
        handlerActive = rescheduled;
      }
    }
  }
  