1 /* 2 * Copyright (C) 2017 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 com.android.dialer.strictmode; 18 19 import android.app.Application; 20 import android.content.Context; 21 import android.os.Looper; 22 import android.os.StrictMode; 23 import android.os.StrictMode.ThreadPolicy; 24 import android.preference.PreferenceManager; 25 import android.support.annotation.AnyThread; 26 import android.support.v4.os.UserManagerCompat; 27 import com.android.dialer.buildtype.BuildType; 28 import com.android.dialer.buildtype.BuildType.Type; 29 import com.android.dialer.function.Supplier; 30 import com.android.dialer.storage.StorageComponent; 31 32 /** Utilities for enforcing strict-mode in an app. */ 33 public final class StrictModeUtils { 34 35 private static final ThreadPolicy THREAD_NO_PENALTY = 36 new StrictMode.ThreadPolicy.Builder().permitAll().build(); 37 38 /** 39 * Convenience method for disabling and enabling the thread policy death penalty using lambdas. 40 * 41 * <p>For example: 42 * 43 * <p><code> 44 * Value foo = StrictModeUtils.bypass(() -> doDiskAccessOnMainThreadReturningValue()); 45 * </code> 46 * 47 * <p>The thread policy is only mutated if this is called from the main thread. 48 */ 49 @AnyThread bypass(Supplier<T> supplier)50 public static <T> T bypass(Supplier<T> supplier) { 51 if (isStrictModeAllowed() && onMainThread()) { 52 ThreadPolicy originalPolicy = StrictMode.getThreadPolicy(); 53 StrictMode.setThreadPolicy(THREAD_NO_PENALTY); 54 try { 55 return supplier.get(); 56 } finally { 57 StrictMode.setThreadPolicy(originalPolicy); 58 } 59 } 60 return supplier.get(); 61 } 62 63 /** 64 * Convenience method for disabling and enabling the thread policy death penalty using lambdas. 65 * 66 * <p>For example: 67 * 68 * <p><code> 69 * StrictModeUtils.bypass(() -> doDiskAccessOnMainThread()); 70 * </code> 71 * 72 * <p>The thread policy is only mutated if this is called from the main thread. 73 */ 74 @AnyThread bypass(Runnable runnable)75 public static void bypass(Runnable runnable) { 76 if (isStrictModeAllowed() && onMainThread()) { 77 ThreadPolicy originalPolicy = StrictMode.getThreadPolicy(); 78 StrictMode.setThreadPolicy(THREAD_NO_PENALTY); 79 try { 80 runnable.run(); 81 } finally { 82 StrictMode.setThreadPolicy(originalPolicy); 83 } 84 } else { 85 runnable.run(); 86 } 87 } 88 isStrictModeAllowed()89 public static boolean isStrictModeAllowed() { 90 return BuildType.get() == Type.BUGFOOD; 91 } 92 onMainThread()93 private static boolean onMainThread() { 94 return Looper.getMainLooper().equals(Looper.myLooper()); 95 } 96 97 /** 98 * We frequently access shared preferences on the main thread, which causes strict mode 99 * violations. When strict mode is allowed, warm up the shared preferences so that later uses of 100 * shared preferences access the in-memory versions and we don't have to bypass strict mode at 101 * every point in the application where shared preferences are accessed. 102 */ warmupSharedPrefs(Application application)103 public static void warmupSharedPrefs(Application application) { 104 // From credential-encrypted (CE) storage, i.e.: 105 // /data/data/com.android.dialer/shared_prefs 106 107 if (UserManagerCompat.isUserUnlocked(application)) { 108 // <package_name>_preferences.xml 109 PreferenceManager.getDefaultSharedPreferences(application); 110 111 // <package_name>.xml 112 application.getSharedPreferences(application.getPackageName(), Context.MODE_PRIVATE); 113 } 114 115 // From device-encrypted (DE) storage, i.e.: 116 // /data/user_de/0/com.android.dialer/shared_prefs/ 117 118 // <package_name>_preferences.xml 119 StorageComponent.get(application).unencryptedSharedPrefs(); 120 } 121 StrictModeUtils()122 private StrictModeUtils() {} 123 } 124