1 /* 2 * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved. 3 * Copyright (c) 2012 JogAmp Community. 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 * - Redistribution of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 12 * - Redistribution 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 Sun Microsystems, Inc. or the names of 17 * contributors may be used to endorse or promote products derived from 18 * this software without specific prior written permission. 19 * 20 * This software is provided "AS IS," without a warranty of any kind. ALL 21 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, 22 * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A 23 * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN 24 * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR 25 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR 26 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR 27 * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR 28 * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE 29 * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, 30 * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF 31 * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 32 * 33 * You acknowledge that this software is not designed or intended for use 34 * in the design, construction, operation or maintenance of any nuclear 35 * facility. 36 * 37 * Sun gratefully acknowledges that this software was originally authored 38 * and developed by Kenneth Bradley Russell and Christopher John Kline. 39 */ 40 41 package com.jogamp.opengl; 42 43 import jogamp.opengl.ThreadingImpl; 44 45 /** This API provides access to the threading model for the implementation of 46 the classes in this package. 47 48 <P> 49 50 OpenGL is specified as a thread-safe API, but in practice there 51 are multithreading-related issues on most, if not all, of the 52 platforms which support it. For example, some OpenGL 53 implementations do not behave well when one context is made 54 current first on one thread, released, and then made current on a 55 second thread, although this is legal according to the OpenGL 56 specification. On other platforms there are other problems. 57 58 <P> 59 60 Due to these limitations, and due to the inherent multithreading 61 in the Java platform (in particular, in the Abstract Window 62 Toolkit), it is often necessary to limit the multithreading 63 occurring in the typical application using the OpenGL API. 64 65 <P> 66 67 In the current reference implementation, for instance, multithreading 68 has been limited by 69 forcing all OpenGL-related work for GLAutoDrawables on to a single 70 thread. In other words, if an application uses only the 71 GLAutoDrawable and GLEventListener callback mechanism, it is 72 guaranteed to have the most correct single-threaded behavior on 73 all platforms. 74 75 <P> 76 77 Applications using the GLContext makeCurrent/release API directly 78 will inherently break this single-threaded model, as these methods 79 require that the OpenGL context be made current on the current 80 thread immediately. For applications wishing to integrate better 81 with an implementation that uses the single-threaded model, this 82 class provides public access to the mechanism used by the implementation. 83 84 <P> 85 86 Users can execute Runnables on the 87 internal thread used for performing OpenGL work, and query whether 88 the current thread is already this thread. Using these mechanisms 89 the user can move work from the current thread on to the internal 90 OpenGL thread if desired. 91 92 <P> 93 94 This class also provides mechanisms for querying whether this 95 internal serialization of OpenGL work is in effect, and a 96 programmatic way of disabling it. In the current reference 97 implementation it is enabled by default, although it could be 98 disabled in the future if OpenGL drivers become more robust on 99 all platforms. 100 101 <P> 102 103 In addition to specifying programmatically whether the single 104 thread for OpenGL work is enabled, users may switch it on and off 105 using the system property <code>jogl.1thread</code>. Valid values 106 for this system property are: 107 108 <PRE> 109 -Djogl.1thread=false Disable single-threading of OpenGL work, hence use multithreading. 110 -Djogl.1thread=true Enable single-threading of OpenGL work (default -- on a newly-created worker thread) 111 -Djogl.1thread=auto Select default single-threading behavior (currently on) 112 -Djogl.1thread=awt Enable single-threading of OpenGL work on AWT event dispatch thread (current default on all 113 platforms, and also the default behavior older releases) 114 -Djogl.1thread=worker Enable single-threading of OpenGL work on newly-created worker thread (not suitable for Mac 115 OS X or X11 platforms, and risky on Windows in applet environments) 116 </PRE> 117 */ 118 119 public class Threading { 120 public static enum Mode { 121 /** 122 * Full multithreaded OpenGL, 123 * i.e. any {@link Threading#invoke(boolean, Runnable, Object) invoke} 124 * {@link Threading#invokeOnOpenGLThread(boolean, Runnable) commands} 125 * will be issued on the current thread immediately. 126 */ 127 MT(0), 128 129 /** Single-Threaded OpenGL on AWT EDT */ 130 ST_AWT(1), 131 132 /** Single-Threaded OpenGL on dedicated worker thread. */ 133 ST_WORKER(2); 134 135 public final int id; 136 Mode(final int id)137 Mode(final int id){ 138 this.id = id; 139 } 140 } 141 142 /** No reason to ever instantiate this class */ Threading()143 private Threading() {} 144 145 /** Returns the threading mode */ getMode()146 public static Mode getMode() { 147 return ThreadingImpl.getMode(); 148 } 149 150 /** If an implementation of the com.jogamp.opengl APIs offers a 151 multithreading option but the default behavior is single-threading, 152 this API provides a mechanism for end users to disable single-threading 153 in this implementation. Users are strongly discouraged from 154 calling this method unless they are aware of all of the 155 consequences and are prepared to enforce some amount of 156 threading restrictions in their applications. Disabling 157 single-threading, for example, may have unintended consequences 158 on GLAutoDrawable implementations such as GLCanvas and GLJPanel. 159 Currently there is no supported way to re-enable it 160 once disabled, partly to discourage careless use of this 161 method. This method should be called as early as possible in an 162 application. */ disableSingleThreading()163 public static final void disableSingleThreading() { 164 ThreadingImpl.disableSingleThreading(); 165 } 166 167 /** Indicates whether OpenGL work is being automatically forced to a 168 single thread in this implementation. */ isSingleThreaded()169 public static final boolean isSingleThreaded() { 170 return ThreadingImpl.isSingleThreaded(); 171 } 172 173 /** Indicates whether the current thread is the designated toolkit thread, 174 if such semantics exists. */ isToolkitThread()175 public static final boolean isToolkitThread() throws GLException { 176 return ThreadingImpl.isToolkitThread(); 177 } 178 179 /** 180 * Indicates whether the current thread is capable of 181 * performing OpenGL-related work. 182 * <p> 183 * Method always returns <code>true</code> 184 * if {@link #getMode()} == {@link Mode#MT} or {@link #isSingleThreaded()} == <code>false</code>. 185 * </p> 186 */ isOpenGLThread()187 public static final boolean isOpenGLThread() throws GLException { 188 return ThreadingImpl.isOpenGLThread(); 189 } 190 191 /** Executes the passed Runnable on the single thread used for all 192 OpenGL work in this com.jogamp.opengl API implementation. It is 193 not specified exactly which thread is used for this 194 purpose. This method should only be called if the single-thread 195 model is in use and if the current thread is not the OpenGL 196 thread (i.e., if <code>isOpenGLThread()</code> returns 197 false). It is up to the end user to check to see whether the 198 current thread is the OpenGL thread and either execute the 199 Runnable directly or perform the work inside it. 200 **/ invokeOnOpenGLThread(final boolean wait, final Runnable r)201 public static final void invokeOnOpenGLThread(final boolean wait, final Runnable r) throws GLException { 202 ThreadingImpl.invokeOnOpenGLThread(wait, r); 203 } 204 205 /** 206 * If not {@link #isOpenGLThread()} 207 * <b>and</b> the <code>lock</code> is not being hold by this thread, 208 * invoke Runnable <code>r</code> on the OpenGL thread via {@link #invokeOnOpenGLThread(boolean, Runnable)}. 209 * <p> 210 * Otherwise invoke Runnable <code>r</code> on the current thread. 211 * </p> 212 * 213 * @param wait set to true for waiting until Runnable <code>r</code> is finished, otherwise false. 214 * @param r the Runnable to be executed 215 * @param lock optional lock object to be tested 216 * @throws GLException 217 */ invoke(final boolean wait, final Runnable r, final Object lock)218 public static final void invoke(final boolean wait, final Runnable r, final Object lock) throws GLException { 219 if ( !isOpenGLThread() && 220 ( null == lock || !Thread.holdsLock(lock) ) ) { 221 invokeOnOpenGLThread(wait, r); 222 } else { 223 r.run(); 224 } 225 } 226 } 227