geode-junit/src/main/java/org/apache/geode/internal/cache/ha/TestBlockingHARegionQueue.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The ASF licenses this file to You 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.apache.geode.internal.cache.ha;

import java.io.IOException;

import org.apache.logging.log4j.Logger;

import org.apache.geode.cache.CacheException;
import org.apache.geode.internal.cache.InternalCache;
import org.apache.geode.internal.statistics.StatisticsClock;
import org.apache.geode.logging.internal.log4j.api.LogService;

/**
 * Test class for Blocking HA region queue functionalities
 *
 *
 *
 */

// TODO:Asif: Modify the test to allow working with the new class containing
// ReadWrite lock functionality
public class TestBlockingHARegionQueue extends TestOnlyHARegionQueue {
  private static final Logger logger = LogService.getLogger();

  /**
   * Object on which to synchronize/wait
   */
  private Object forWaiting = new Object();

  boolean takeFirst = false;

  boolean takeWhenPeekInProgress = false;

  public TestBlockingHARegionQueue(String regionName, InternalCache cache,
      StatisticsClock statisticsClock)
      throws IOException, ClassNotFoundException, CacheException, InterruptedException {
    super(regionName, cache, statisticsClock);
  }

  /**
   * Does a put and a notifyAll() multiple threads can possibly be waiting on this queue to put
   *
   *
   * @return boolean whether object was successfully put onto the queue
   */

  @Override
  public boolean put(Object object) throws CacheException, InterruptedException {
    boolean putDone = super.put(object);

    if (takeFirst) {
      this.take();
      this.takeFirst = false;
    }

    synchronized (forWaiting) {
      forWaiting.notifyAll();
    }
    return putDone;
  }

  /**
   * blocking peek. This method will not return till it has acquired a legitimate object from the
   * queue.
   *
   */

  @Override
  public Object peek() throws InterruptedException {
    Object object = null;
    while (true) {

      if (takeWhenPeekInProgress) {
        try {
          this.take();
        } catch (CacheException ce) {
          throw new RuntimeException(ce) {};
        }
        this.takeWhenPeekInProgress = false;
      }
      object = super.peek();
      if (object == null) {
        synchronized (forWaiting) {
          object = super.peek();

          if (object == null) {
            boolean interrupted = Thread.interrupted();
            try {
              forWaiting.wait();
            } catch (InterruptedException e) {
              interrupted = true;
              /** ignore* */
              if (logger.isDebugEnabled()) {
                logger.debug("Interrupted exception while wait for peek", e);
              }
            } finally {
              if (interrupted) {
                Thread.currentThread().interrupt();
              }
            }
          } else {
            break;
          }
        }
      } else {
        break;
      }
    }
    return object;
  }
}