package org.apache.maven.surefire.junitcore.pc;

 /*

  * 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.

  */

 import org.junit.runner.Computer;

 import org.junit.runner.Description;

 import java.util.Collection;

 import java.util.concurrent.Callable;

 import java.util.concurrent.Executors;

 import java.util.concurrent.Future;

 import java.util.concurrent.ScheduledExecutorService;

 import java.util.concurrent.TimeUnit;

 /**

  * ParallelComputer extends JUnit {@link Computer} and has a shutdown functionality.

  *

  * @author Tibor Digana (tibor17)

  * @since 2.16

  *

  * @see ParallelComputerBuilder

  */

 public abstract class ParallelComputer extends Computer

 {

     private ScheduledExecutorService shutdownScheduler;

     public abstract Collection<Description> shutdown( boolean shutdownNow );

     protected final void afterRunQuietly()

     {

         if ( shutdownScheduler != null )

         {

             shutdownScheduler.shutdownNow();

         }

     }

     public Future<Collection<Description>> scheduleShutdown( int timeout, TimeUnit unit )

     {

         return getShutdownScheduler().schedule( createShutdownTask( false ), timeout, unit );

     }

     public Future<Collection<Description>> scheduleForcedShutdown( int timeout, TimeUnit unit )

     {

         return getShutdownScheduler().schedule( createShutdownTask( true ), timeout, unit );

     }

     private ScheduledExecutorService getShutdownScheduler()

     {

         if ( shutdownScheduler == null )

         {

             shutdownScheduler = Executors.newScheduledThreadPool( 2 );

         }

         return shutdownScheduler;

     }

     private Callable<Collection<Description>> createShutdownTask( final boolean isForced )

     {

         return new Callable<Collection<Description>>()

         {

             public Collection<Description> call() throws Exception

             {

                 return shutdown( isForced );

             }

         };

     }

 }