/*

  * 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.giraph.zk;

 import org.apache.hadoop.mapreduce.Mapper.Context;

 /**

  * A lock that will keep the job context updated while waiting.

  */

 public class ContextLock extends PredicateLock {

   /** Msecs to refresh the progress meter */

   private static final int MSEC_PERIOD = 10000;

   /** Job context (for progress) */

   @SuppressWarnings("rawtypes")

   private final Context context;

   /**

    * Constructor.

    *

    * @param context used to call progress()

    */

   ContextLock(@SuppressWarnings("rawtypes") Context context) {

     this.context = context;

   }

   /**

    * Specialized version of waitForever() that will keep the job progressing

    * while waiting.

    */

   @Override

   public void waitForever() {

     while (!waitMsecs(MSEC_PERIOD)) {

       context.progress();

     }

   }

 }