1 /*
   2  * Copyright (c) 2014, 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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package com.oracle.graal.hotspot.hsail;
  24 
  25 import static com.oracle.graal.hotspot.hsail.HSAILHotSpotBackend.Options.*;
  26 
  27 import java.util.concurrent.*;
  28 
  29 import com.oracle.graal.hotspot.hsail.HSAILHotSpotBackend.Options;
  30 
  31 /**
  32  * Thread pool for HSAIL allocation support.
  33  */
  34 public class DonorThreadPool {
  35 
  36     private final Thread[] threads;
  37 
  38     void waitAt(CyclicBarrier barrier) {
  39         try {
  40             barrier.await();
  41         } catch (Exception e) {
  42             e.printStackTrace();
  43         }
  44     }
  45 
  46     /**
  47      * Creates a pool of threads whose size is given by {@link Options#HsailDonorThreads}.
  48      */
  49     DonorThreadPool() {
  50         int size = HsailDonorThreads.getValue();
  51         this.threads = new Thread[size];
  52         CyclicBarrier barrier = new CyclicBarrier(size + 1);
  53 
  54         // fill in threads
  55         for (int i = 0; i < size; i++) {
  56             threads[i] = new Thread(new Runnable() {
  57                 @Override
  58                 public void run() {
  59                     while (true) {
  60                         waitAt(barrier);
  61                     }
  62                 }
  63             }, "HsailDonorThread-" + i);
  64             threads[i].setDaemon(true);
  65             threads[i].start();
  66         }
  67         // creating thread waits at barrier to make sure others have started
  68         waitAt(barrier);
  69     }
  70 
  71     public Thread[] getThreads() {
  72         return threads;
  73     }
  74 }