001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.client;
019
020import java.util.List;
021import java.util.Map;
022import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
023import org.apache.yetus.audience.InterfaceAudience;
024import org.slf4j.Logger;
025import org.slf4j.LoggerFactory;
026
027/**
028 * A wrapper for a runnable for a group of actions for a single regionserver.
029 * <p>
030 * This can be used to build up the actions that should be taken and then
031 * </p>
032 * <p>
033 * This class exists to simulate using a ScheduledExecutorService with just a regular
034 * ExecutorService and Runnables. It is used for legacy reasons in the the client; this could only
035 * be removed if we change the expectations in HTable around the pool the client is able to pass in
036 * and even if we deprecate the current APIs would require keeping this class around for the interim
037 * to bridge between the legacy ExecutorServices and the scheduled pool.
038 * </p>
039 */
040@InterfaceAudience.Private
041public class DelayingRunner implements Runnable {
042  private static final Logger LOG = LoggerFactory.getLogger(DelayingRunner.class);
043
044  private final Object sleepLock = new Object();
045  private boolean triggerWake = false;
046  private long sleepTime;
047  private MultiAction actions = new MultiAction();
048  private Runnable runnable;
049
050  public DelayingRunner(long sleepTime, Map.Entry<byte[], List<Action>> e) {
051    this.sleepTime = sleepTime;
052    add(e);
053  }
054
055  public void setRunner(Runnable runner) {
056    this.runnable = runner;
057  }
058
059  @Override
060  public void run() {
061    if (!sleep()) {
062      LOG.warn("Interrupted while sleeping for expected sleep time " + sleepTime + " ms");
063    }
064    // TODO maybe we should consider switching to a listenableFuture for the actual callable and
065    // then handling the results/errors as callbacks. That way we can decrement outstanding tasks
066    // even if we get interrupted here, but for now, we still need to run so we decrement the
067    // outstanding tasks
068    this.runnable.run();
069  }
070
071  /**
072   * Sleep for an expected amount of time.
073   * <p>
074   * This is nearly a copy of what the Sleeper does, but with the ability to know if you got
075   * interrupted while sleeping.
076   * </p>
077   * @return <tt>true</tt> if the sleep completely entirely successfully, but otherwise
078   *         <tt>false</tt> if the sleep was interrupted.
079   */
080  private boolean sleep() {
081    long now = EnvironmentEdgeManager.currentTime();
082    long startTime = now;
083    long waitTime = sleepTime;
084    while (waitTime > 0) {
085      long woke = -1;
086      try {
087        synchronized (sleepLock) {
088          if (triggerWake) break;
089          sleepLock.wait(waitTime);
090        }
091        woke = EnvironmentEdgeManager.currentTime();
092      } catch (InterruptedException iex) {
093        return false;
094      }
095      // Recalculate waitTime.
096      woke = (woke == -1) ? EnvironmentEdgeManager.currentTime() : woke;
097      waitTime = waitTime - (woke - startTime);
098    }
099    return true;
100  }
101
102  public void add(Map.Entry<byte[], List<Action>> e) {
103    actions.add(e.getKey(), e.getValue());
104  }
105
106  public MultiAction getActions() {
107    return actions;
108  }
109
110  public long getSleepTime() {
111    return sleepTime;
112  }
113}