1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.opengl; 18 19 import static javax.microedition.khronos.egl.EGL10.EGL_DEFAULT_DISPLAY; 20 import static javax.microedition.khronos.egl.EGL10.EGL_NO_DISPLAY; 21 22 import java.util.ArrayList; 23 24 import javax.microedition.khronos.egl.EGL10; 25 import javax.microedition.khronos.egl.EGLContext; 26 import javax.microedition.khronos.egl.EGLDisplay; 27 28 import android.os.Looper; 29 import android.util.Log; 30 31 import com.google.android.gles_jni.EGLImpl; 32 33 /** 34 * The per-process memory overhead of hardware accelerated graphics can 35 * be quite large on some devices. For small memory devices, being able to 36 * terminate all EGL contexts so that this graphics driver memory can be 37 * reclaimed can significant improve the overall behavior of the device. This 38 * class helps app developers participate in releasing their EGL context 39 * when appropriate and possible. 40 * 41 * <p>To use, simple instantiate this class with the EGLContext you create. 42 * When you have done this, if the device is getting low on memory and all 43 * of the currently created EGL contexts in the process are being managed 44 * through this class, then they will all be asked to terminate through the 45 * call to {@link #onTerminate}. 46 * 47 * @hide 48 */ 49 public abstract class ManagedEGLContext { 50 static final String TAG = "ManagedEGLContext"; 51 52 static final ArrayList<ManagedEGLContext> sActive = new ArrayList<ManagedEGLContext>(); 53 54 final EGLContext mContext; 55 56 /** 57 * Instantiate to manage the given EGLContext. 58 */ ManagedEGLContext(EGLContext context)59 public ManagedEGLContext(EGLContext context) { 60 mContext = context; 61 synchronized (sActive) { 62 sActive.add(this); 63 } 64 } 65 66 /** 67 * Retrieve the EGLContext being managed by the class. 68 */ getContext()69 public EGLContext getContext() { 70 return mContext; 71 } 72 73 /** 74 * Force-terminate the ManagedEGLContext. This will cause 75 * {@link #onTerminate(EGLContext)} to be called. You <em>must</em> 76 * call this when destroying the EGLContext, so that the framework 77 * knows to stop managing it. 78 */ terminate()79 public void terminate() { 80 execTerminate(); 81 } 82 execTerminate()83 void execTerminate() { 84 onTerminate(mContext); 85 } 86 87 /** 88 * Override this method to destroy the EGLContext when appropriate. 89 * <em>Note that this method is always called on the main thread 90 * of the process.</em> If your EGLContext was created on a different 91 * thread, you will need to implement this method to hand off the work 92 * of destroying the context to that thread. 93 */ onTerminate(EGLContext context)94 public abstract void onTerminate(EGLContext context); 95 96 /** @hide */ doTerminate()97 public static boolean doTerminate() { 98 ArrayList<ManagedEGLContext> active; 99 100 if (Looper.getMainLooper() != Looper.myLooper()) { 101 throw new IllegalStateException("Called on wrong thread"); 102 } 103 104 synchronized (sActive) { 105 // If there are no active managed contexts, we will not even 106 // try to terminate. 107 if (sActive.size() <= 0) { 108 return false; 109 } 110 111 // Need to check how many EGL contexts are actually running, 112 // to compare with how many we are managing. 113 EGL10 egl = (EGL10) EGLContext.getEGL(); 114 EGLDisplay display = egl.eglGetDisplay(EGL_DEFAULT_DISPLAY); 115 116 if (display == EGL_NO_DISPLAY) { 117 Log.w(TAG, "doTerminate failed: no display"); 118 return false; 119 } 120 121 if (EGLImpl.getInitCount(display) != sActive.size()) { 122 Log.w(TAG, "doTerminate failed: EGL count is " + EGLImpl.getInitCount(display) 123 + " but managed count is " + sActive.size()); 124 return false; 125 } 126 127 active = new ArrayList<ManagedEGLContext>(sActive); 128 sActive.clear(); 129 } 130 131 for (int i = 0; i < active.size(); i++) { 132 active.get(i).execTerminate(); 133 } 134 135 return true; 136 } 137 } 138