GraphicsEnvironment.java revision fd104e7fde7f53700da58cbab57d73b938b837a7 
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
17package android.os;
18
19import android.content.Context;
20import android.content.pm.ApplicationInfo;
21import android.content.pm.PackageManager;
22import android.opengl.EGL14;
23import android.os.SystemProperties;
24import android.util.Log;
25
26import dalvik.system.VMRuntime;
27
28import java.io.File;
29
30/** @hide */
31public final class GraphicsEnvironment {
32
33    private static final boolean DEBUG = false;
34    private static final String TAG = "GraphicsEnvironment";
35    private static final String PROPERTY_GFX_DRIVER = "ro.gfx.driver.0";
36
37    public static void setupGraphicsEnvironment(Context context) {
38        chooseDriver(context);
39
40        // Now that we've figured out which driver to use for this process, load and initialize it.
41        // This can take multiple frame periods, and it would otherwise happen as part of the first
42        // frame, increasing first-frame latency. Starting it here, as a low-priority background
43        // thread, means that it's usually done long before we start drawing the first frame,
44        // without significantly disrupting other activity launch work.
45        Thread eglInitThread = new Thread(
46                () -> {
47                    Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
48                    EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
49                },
50                "EGL Init");
51        eglInitThread.start();
52    }
53
54    private static void chooseDriver(Context context) {
55        String driverPackageName = SystemProperties.get(PROPERTY_GFX_DRIVER);
56        if (driverPackageName == null || driverPackageName.isEmpty()) {
57            return;
58        }
59        // To minimize risk of driver updates crippling the device beyond user repair, never use an
60        // updated driver for privileged or non-updated system apps. Presumably pre-installed apps
61        // were tested thoroughly with the pre-installed driver.
62        ApplicationInfo ai = context.getApplicationInfo();
63        if (ai.isPrivilegedApp() || (ai.isSystemApp() && !ai.isUpdatedSystemApp())) {
64            if (DEBUG) Log.v(TAG, "ignoring driver package for privileged/non-updated system app");
65            return;
66        }
67        ApplicationInfo driverInfo;
68        try {
69            driverInfo = context.getPackageManager().getApplicationInfo(driverPackageName,
70                    PackageManager.MATCH_SYSTEM_ONLY);
71        } catch (PackageManager.NameNotFoundException e) {
72            Log.w(TAG, "driver package '" + driverPackageName + "' not installed");
73            return;
74        }
75        String abi = chooseAbi(driverInfo);
76        if (abi == null) {
77            if (DEBUG) {
78                // This is the normal case for the pre-installed empty driver package, don't spam
79                if (driverInfo.isUpdatedSystemApp()) {
80                    Log.w(TAG, "updated driver package has no compatible native libraries");
81                }
82            }
83            return;
84        }
85
86        StringBuilder sb = new StringBuilder();
87        sb.append(driverInfo.nativeLibraryDir)
88          .append(File.pathSeparator);
89        sb.append(driverInfo.sourceDir)
90          .append("!/lib/")
91          .append(abi);
92        String paths = sb.toString();
93
94        if (DEBUG) Log.v(TAG, "gfx driver package libs: " + paths);
95        setDriverPath(paths);
96    }
97
98    private static String chooseAbi(ApplicationInfo ai) {
99        String isa = VMRuntime.getCurrentInstructionSet();
100        if (ai.primaryCpuAbi != null &&
101                isa.equals(VMRuntime.getInstructionSet(ai.primaryCpuAbi))) {
102            return ai.primaryCpuAbi;
103        }
104        if (ai.secondaryCpuAbi != null &&
105                isa.equals(VMRuntime.getInstructionSet(ai.secondaryCpuAbi))) {
106            return ai.secondaryCpuAbi;
107        }
108        return null;
109    }
110
111    private static native void setDriverPath(String path);
112
113}
114