1 /* 2 * Copyright (c) 2009-2010 jMonkeyEngine 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 12 * * Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * * Neither the name of 'jMonkeyEngine' nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 24 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 27 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 28 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 29 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 30 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 package com.jme3.app; 33 34 import java.util.concurrent.*; 35 import java.util.concurrent.locks.Condition; 36 import java.util.concurrent.locks.ReentrantLock; 37 import java.util.logging.Level; 38 import java.util.logging.Logger; 39 40 /** 41 * <code>AppTask</code> is used in <code>AppTaskQueue</code> to manage tasks that have 42 * yet to be accomplished. The AppTask system is used to execute tasks either 43 * in the OpenGL/Render thread, or outside of it. 44 * 45 * @author Matthew D. Hicks, lazloh 46 */ 47 public class AppTask<V> implements Future<V> { 48 private static final Logger logger = Logger.getLogger(AppTask.class 49 .getName()); 50 51 private final Callable<V> callable; 52 53 private V result; 54 private ExecutionException exception; 55 private boolean cancelled, finished; 56 private final ReentrantLock stateLock = new ReentrantLock(); 57 private final Condition finishedCondition = stateLock.newCondition(); 58 59 /** 60 * Create an <code>AppTask</code> that will execute the given 61 * {@link Callable}. 62 * 63 * @param callable The callable to be executed 64 */ AppTask(Callable<V> callable)65 public AppTask(Callable<V> callable) { 66 this.callable = callable; 67 } 68 cancel(boolean mayInterruptIfRunning)69 public boolean cancel(boolean mayInterruptIfRunning) { 70 stateLock.lock(); 71 try { 72 if (result != null) { 73 return false; 74 } 75 cancelled = true; 76 77 finishedCondition.signalAll(); 78 79 return true; 80 } finally { 81 stateLock.unlock(); 82 } 83 } 84 get()85 public V get() throws InterruptedException, ExecutionException { 86 stateLock.lock(); 87 try { 88 while (!isDone()) { 89 finishedCondition.await(); 90 } 91 if (exception != null) { 92 throw exception; 93 } 94 return result; 95 } finally { 96 stateLock.unlock(); 97 } 98 } 99 get(long timeout, TimeUnit unit)100 public V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException { 101 stateLock.lock(); 102 try { 103 if (!isDone()) { 104 finishedCondition.await(timeout, unit); 105 } 106 if (exception != null) { 107 throw exception; 108 } 109 if (result == null) { 110 throw new TimeoutException("Object not returned in time allocated."); 111 } 112 return result; 113 } finally { 114 stateLock.unlock(); 115 } 116 } 117 isCancelled()118 public boolean isCancelled() { 119 stateLock.lock(); 120 try { 121 return cancelled; 122 } finally { 123 stateLock.unlock(); 124 } 125 } 126 isDone()127 public boolean isDone() { 128 stateLock.lock(); 129 try { 130 return finished || cancelled || (exception != null); 131 } finally { 132 stateLock.unlock(); 133 } 134 } 135 getCallable()136 public Callable<V> getCallable() { 137 return callable; 138 } 139 invoke()140 public void invoke() { 141 try { 142 final V tmpResult = callable.call(); 143 144 stateLock.lock(); 145 try { 146 result = tmpResult; 147 finished = true; 148 149 finishedCondition.signalAll(); 150 } finally { 151 stateLock.unlock(); 152 } 153 } catch (Exception e) { 154 logger.logp(Level.SEVERE, this.getClass().toString(), "invoke()", "Exception", e); 155 156 stateLock.lock(); 157 try { 158 exception = new ExecutionException(e); 159 160 finishedCondition.signalAll(); 161 } finally { 162 stateLock.unlock(); 163 } 164 } 165 } 166 167 }