common/util/src/main/java/org/opendaylight/yangtools/util/concurrent/CountingRejectedExecutionHandler.java

   1 /*
   2  * Copyright (c) 2014 Brocade Communications Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.yangtools.util.concurrent;
  10
  11 import java.util.concurrent.RejectedExecutionHandler;
  12 import java.util.concurrent.ThreadPoolExecutor;
  13 import java.util.concurrent.atomic.AtomicLong;
  14
  15 import org.opendaylight.yangtools.util.ExecutorServiceUtil;
  16
  17 import com.google.common.base.Preconditions;
  18
  19 /**
  20  * A RejectedExecutionHandler that delegates to a backing RejectedExecutionHandler and counts the
  21  * number of rejected tasks.
  22  *
  23  * @author Thomas Pantelis
  24  */
  25 public class CountingRejectedExecutionHandler implements RejectedExecutionHandler {
  26
  27     private final RejectedExecutionHandler delegate;
  28     private final AtomicLong rejectedTaskCounter = new AtomicLong();
  29
  30     /**
  31      * Constructor.
  32      *
  33      * @param delegate the backing RejectedExecutionHandler.
  34      */
  35     public CountingRejectedExecutionHandler( RejectedExecutionHandler delegate ) {
  36         this.delegate = Preconditions.checkNotNull( delegate );
  37     }
  38
  39     @Override
  40     public void rejectedExecution( Runnable task, ThreadPoolExecutor executor ) {
  41         rejectedTaskCounter.incrementAndGet();
  42         delegate.rejectedExecution( task, executor );
  43     }
  44
  45     /**
  46      * Returns the rejected task count.
  47      */
  48     public long getRejectedTaskCount(){
  49         return rejectedTaskCounter.get();
  50     }
  51
  52     /**
  53      * Returns s counting handler for rejected tasks that runs the rejected task directly in the
  54      * calling thread of the execute method, unless the executor has been shut down, in which case
  55      * the task is discarded.
  56      */
  57     public static CountingRejectedExecutionHandler newCallerRunsPolicy() {
  58         return new CountingRejectedExecutionHandler( new ThreadPoolExecutor.CallerRunsPolicy() );
  59     }
  60
  61     /**
  62      * Returns a counting handler for rejected tasks that throws a RejectedExecutionException.
  63      */
  64     public static CountingRejectedExecutionHandler newAbortPolicy() {
  65         return new CountingRejectedExecutionHandler( new ThreadPoolExecutor.AbortPolicy() );
  66     }
  67
  68     /**
  69      * Returns a counting handler for rejected tasks that that blocks on the
  70      * {@link ThreadPoolExecutor}'s backing queue until it can add the task to the queue.
  71      */
  72     public static CountingRejectedExecutionHandler newCallerWaitsPolicy() {
  73         return new CountingRejectedExecutionHandler( ExecutorServiceUtil.waitInQueueExecutionHandler() );
  74     }
  75 }