1 /*
2  * Copyright 2016 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.os;
18 
19 import android.content.Context;
20 import android.content.pm.ApplicationInfo;
21 import android.content.pm.PackageManager;
22 import android.opengl.EGL14;
23 import android.os.Build;
24 import android.os.SystemProperties;
25 import android.provider.Settings;
26 import android.util.Log;
27 
28 import dalvik.system.VMRuntime;
29 
30 import java.io.File;
31 
32 /** @hide */
33 public class GraphicsEnvironment {
34 
35     private static final GraphicsEnvironment sInstance = new GraphicsEnvironment();
36 
37     /**
38      * Returns the shared {@link GraphicsEnvironment} instance.
39      */
getInstance()40     public static GraphicsEnvironment getInstance() {
41         return sInstance;
42     }
43 
44     private static final boolean DEBUG = false;
45     private static final String TAG = "GraphicsEnvironment";
46     private static final String PROPERTY_GFX_DRIVER = "ro.gfx.driver.0";
47 
48     private ClassLoader mClassLoader;
49     private String mLayerPath;
50     private String mDebugLayerPath;
51 
52     /**
53      * Set up GraphicsEnvironment
54      */
setup(Context context)55     public void setup(Context context) {
56         setupGpuLayers(context);
57         chooseDriver(context);
58     }
59 
60     /**
61      * Check whether application is debuggable
62      */
isDebuggable(Context context)63     private static boolean isDebuggable(Context context) {
64         return (context.getApplicationInfo().flags & ApplicationInfo.FLAG_DEBUGGABLE) > 0;
65     }
66 
67     /**
68      * Store the layer paths available to the loader.
69      */
setLayerPaths(ClassLoader classLoader, String layerPath, String debugLayerPath)70     public void setLayerPaths(ClassLoader classLoader,
71                               String layerPath,
72                               String debugLayerPath) {
73         // We have to store these in the class because they are set up before we
74         // have access to the Context to properly set up GraphicsEnvironment
75         mClassLoader = classLoader;
76         mLayerPath = layerPath;
77         mDebugLayerPath = debugLayerPath;
78     }
79 
80     /**
81      * Set up layer search paths for all apps
82      * If debuggable, check for additional debug settings
83      */
setupGpuLayers(Context context)84     private void setupGpuLayers(Context context) {
85 
86         String layerPaths = "";
87 
88         // Only enable additional debug functionality if the following conditions are met:
89         // 1. App is debuggable
90         // 2. ENABLE_GPU_DEBUG_LAYERS is true
91         // 3. Package name is equal to GPU_DEBUG_APP
92 
93         if (isDebuggable(context)) {
94 
95             int enable = Settings.Global.getInt(context.getContentResolver(),
96                                                 Settings.Global.ENABLE_GPU_DEBUG_LAYERS, 0);
97 
98             if (enable != 0) {
99 
100                 String gpuDebugApp = Settings.Global.getString(context.getContentResolver(),
101                                                                Settings.Global.GPU_DEBUG_APP);
102 
103                 String packageName = context.getPackageName();
104 
105                 if ((gpuDebugApp != null && packageName != null)
106                         && (!gpuDebugApp.isEmpty() && !packageName.isEmpty())
107                         && gpuDebugApp.equals(packageName)) {
108                     Log.i(TAG, "GPU debug layers enabled for " + packageName);
109 
110                     // Prepend the debug layer path as a searchable path.
111                     // This will ensure debug layers added will take precedence over
112                     // the layers specified by the app.
113                     layerPaths = mDebugLayerPath + ":";
114 
115                     String layers = Settings.Global.getString(context.getContentResolver(),
116                                                               Settings.Global.GPU_DEBUG_LAYERS);
117 
118                     Log.i(TAG, "Debug layer list: " + layers);
119                     if (layers != null && !layers.isEmpty()) {
120                         setDebugLayers(layers);
121                     }
122                 }
123             }
124 
125         }
126 
127         // Include the app's lib directory in all cases
128         layerPaths += mLayerPath;
129 
130         setLayerPaths(mClassLoader, layerPaths);
131     }
132 
133     /**
134      * Choose whether the current process should use the builtin or an updated driver.
135      */
chooseDriver(Context context)136     private static void chooseDriver(Context context) {
137         String driverPackageName = SystemProperties.get(PROPERTY_GFX_DRIVER);
138         if (driverPackageName == null || driverPackageName.isEmpty()) {
139             return;
140         }
141         // To minimize risk of driver updates crippling the device beyond user repair, never use an
142         // updated driver for privileged or non-updated system apps. Presumably pre-installed apps
143         // were tested thoroughly with the pre-installed driver.
144         ApplicationInfo ai = context.getApplicationInfo();
145         if (ai.isPrivilegedApp() || (ai.isSystemApp() && !ai.isUpdatedSystemApp())) {
146             if (DEBUG) Log.v(TAG, "ignoring driver package for privileged/non-updated system app");
147             return;
148         }
149         ApplicationInfo driverInfo;
150         try {
151             driverInfo = context.getPackageManager().getApplicationInfo(driverPackageName,
152                     PackageManager.MATCH_SYSTEM_ONLY);
153         } catch (PackageManager.NameNotFoundException e) {
154             Log.w(TAG, "driver package '" + driverPackageName + "' not installed");
155             return;
156         }
157         String abi = chooseAbi(driverInfo);
158         if (abi == null) {
159             if (DEBUG) {
160                 // This is the normal case for the pre-installed empty driver package, don't spam
161                 if (driverInfo.isUpdatedSystemApp()) {
162                     Log.w(TAG, "updated driver package has no compatible native libraries");
163                 }
164             }
165             return;
166         }
167         if (driverInfo.targetSdkVersion < Build.VERSION_CODES.O) {
168             // O drivers are restricted to the sphal linker namespace, so don't try to use
169             // packages unless they declare they're compatible with that restriction.
170             Log.w(TAG, "updated driver package is not known to be compatible with O");
171             return;
172         }
173 
174         StringBuilder sb = new StringBuilder();
175         sb.append(driverInfo.nativeLibraryDir)
176           .append(File.pathSeparator);
177         sb.append(driverInfo.sourceDir)
178           .append("!/lib/")
179           .append(abi);
180         String paths = sb.toString();
181 
182         if (DEBUG) Log.v(TAG, "gfx driver package libs: " + paths);
183         setDriverPath(paths);
184     }
185 
186     /**
187      * Start a background thread to initialize EGL.
188      *
189      * Initializing EGL involves loading and initializing the graphics driver. Some drivers take
190      * several 10s of milliseconds to do this, so doing it on-demand when an app tries to render
191      * its first frame adds directly to user-visible app launch latency. By starting it earlier
192      * on a separate thread, it can usually be finished well before the UI is ready to be drawn.
193      *
194      * Should only be called after chooseDriver().
195      */
earlyInitEGL()196     public static void earlyInitEGL() {
197         Thread eglInitThread = new Thread(
198                 () -> {
199                     EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
200                 },
201                 "EGL Init");
202         eglInitThread.start();
203     }
204 
chooseAbi(ApplicationInfo ai)205     private static String chooseAbi(ApplicationInfo ai) {
206         String isa = VMRuntime.getCurrentInstructionSet();
207         if (ai.primaryCpuAbi != null &&
208                 isa.equals(VMRuntime.getInstructionSet(ai.primaryCpuAbi))) {
209             return ai.primaryCpuAbi;
210         }
211         if (ai.secondaryCpuAbi != null &&
212                 isa.equals(VMRuntime.getInstructionSet(ai.secondaryCpuAbi))) {
213             return ai.secondaryCpuAbi;
214         }
215         return null;
216     }
217 
setLayerPaths(ClassLoader classLoader, String layerPaths)218     private static native void setLayerPaths(ClassLoader classLoader, String layerPaths);
setDebugLayers(String layers)219     private static native void setDebugLayers(String layers);
setDriverPath(String path)220     private static native void setDriverPath(String path);
221 }
222