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.apache.maven.surefire.report.ConsoleStream;
  
  import java.util.Collection;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Future;
  import java.util.concurrent.ThreadPoolExecutor;
  import java.util.concurrent.TimeUnit;
  
  /**
   * Abstract parallel scheduling strategy in private package.
   * The remaining abstract methods have to be implemented differently
   * depending if the thread pool is shared with other strategies or not.
   *
   * @author Tibor Digana (tibor17)
   * @see SchedulingStrategy
   * @see SharedThreadPoolStrategy
   * @see NonSharedThreadPoolStrategy
   * @since 2.16
   */
  abstract class AbstractThreadPoolStrategy
      extends SchedulingStrategy
  {
      private final ExecutorService threadPool;
  
      private final Collection<Future<?>> futureResults;
  
      private volatile boolean isDestroyed;
  
      AbstractThreadPoolStrategy( ConsoleStream logger, ExecutorService threadPool )
      {
          this( logger, threadPool, null );
      }
  
      AbstractThreadPoolStrategy( ConsoleStream logger, ExecutorService threadPool, Collection<Future<?>> futureResults )
      {
          super( logger );
          this.threadPool = threadPool;
          this.futureResults = futureResults;
      }
  
      protected final ExecutorService getThreadPool()
      {
          return threadPool;
      }
  
      protected final Collection<Future<?>> getFutureResults()
      {
          return futureResults;
      }
  
      @Override
      public void schedule( Runnable task )
      {
          if ( canSchedule() )
          {
              Future<?> futureResult = threadPool.submit( task );
              if ( futureResults != null )
              {
                  futureResults.add( futureResult );
              }
          }
      }
  
      @Override
      protected boolean stop()
      {
          boolean wasRunning = disable();
          if ( threadPool.isShutdown() )
          {
              wasRunning = false;
          }
          else
          {
              threadPool.shutdown();
          }
          return wasRunning;
      }
  
     @Override
     protected boolean stopNow()
     {
         boolean wasRunning = disable();
         if ( threadPool.isShutdown() )
         {
             wasRunning = false;
         }
         else
         {
             threadPool.shutdownNow();
         }
         return wasRunning;
     }
 
     /**
      * @see Scheduler.ShutdownHandler
      */
     @Override
     protected void setDefaultShutdownHandler( Scheduler.ShutdownHandler handler )
     {
         if ( threadPool instanceof ThreadPoolExecutor )
         {
             ThreadPoolExecutor pool = (ThreadPoolExecutor) threadPool;
             handler.setRejectedExecutionHandler( pool.getRejectedExecutionHandler() );
             pool.setRejectedExecutionHandler( handler );
         }
     }
 
     @Override
     public boolean destroy()
     {
         try
         {
             if ( !isDestroyed )//just an optimization
             {
                 disable();
                 threadPool.shutdown();
                 this.isDestroyed |= threadPool.awaitTermination( Long.MAX_VALUE, TimeUnit.NANOSECONDS );
             }
             return isDestroyed;
         }
         catch ( InterruptedException e )
         {
             return false;
         }
     }
 }