1 /*
   2  * Copyright (c) 2008, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any

  44  */
  45 
  46 abstract class AsynchronousChannelGroupImpl
  47     extends AsynchronousChannelGroup implements Executor
  48 {
  49     // number of internal threads handling I/O events when using an unbounded
  50     // thread pool. Internal threads do not dispatch to completion handlers.
  51     private static final int internalThreadCount = AccessController.doPrivileged(
  52         new GetIntegerAction("sun.nio.ch.internalThreadPoolSize", 1));
  53 
  54     // associated thread pool
  55     private final ThreadPool pool;
  56 
  57     // number of tasks running (including internal)
  58     private final AtomicInteger threadCount = new AtomicInteger();
  59 
  60     // associated Executor for timeouts
  61     private ScheduledThreadPoolExecutor timeoutExecutor;
  62 
  63     // task queue for when using a fixed thread pool. In that case, thread
  64     // waiting on I/O events must be awokon to poll tasks from this queue.
  65     private final Queue<Runnable> taskQueue;
  66 
  67     // group shutdown
  68     private final AtomicBoolean shutdown = new AtomicBoolean();
  69     private final Object shutdownNowLock = new Object();
  70     private volatile boolean terminateInitiated;
  71 
  72     AsynchronousChannelGroupImpl(AsynchronousChannelProvider provider,
  73                                  ThreadPool pool)
  74     {
  75         super(provider);
  76         this.pool = pool;
  77 
  78         if (pool.isFixedThreadPool()) {
  79             taskQueue = new ConcurrentLinkedQueue<>();
  80         } else {
  81             taskQueue = null;   // not used
  82         }
  83 
  84         // use default thread factory as thread should not be visible to

   1 /*
   2  * Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any

  44  */
  45 
  46 abstract class AsynchronousChannelGroupImpl
  47     extends AsynchronousChannelGroup implements Executor
  48 {
  49     // number of internal threads handling I/O events when using an unbounded
  50     // thread pool. Internal threads do not dispatch to completion handlers.
  51     private static final int internalThreadCount = AccessController.doPrivileged(
  52         new GetIntegerAction("sun.nio.ch.internalThreadPoolSize", 1));
  53 
  54     // associated thread pool
  55     private final ThreadPool pool;
  56 
  57     // number of tasks running (including internal)
  58     private final AtomicInteger threadCount = new AtomicInteger();
  59 
  60     // associated Executor for timeouts
  61     private ScheduledThreadPoolExecutor timeoutExecutor;
  62 
  63     // task queue for when using a fixed thread pool. In that case, thread
  64     // waiting on I/O events must be awoken to poll tasks from this queue.
  65     private final Queue<Runnable> taskQueue;
  66 
  67     // group shutdown
  68     private final AtomicBoolean shutdown = new AtomicBoolean();
  69     private final Object shutdownNowLock = new Object();
  70     private volatile boolean terminateInitiated;
  71 
  72     AsynchronousChannelGroupImpl(AsynchronousChannelProvider provider,
  73                                  ThreadPool pool)
  74     {
  75         super(provider);
  76         this.pool = pool;
  77 
  78         if (pool.isFixedThreadPool()) {
  79             taskQueue = new ConcurrentLinkedQueue<>();
  80         } else {
  81             taskQueue = null;   // not used
  82         }
  83 
  84         // use default thread factory as thread should not be visible to