1 /* 2 * Copyright (C) 2018 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 dalvik.system; 18 19 import static android.annotation.SystemApi.Client.MODULE_LIBRARIES; 20 21 import android.annotation.SystemApi; 22 23 import java.util.Objects; 24 import java.util.TimeZone; 25 import java.util.function.Supplier; 26 import libcore.util.NonNull; 27 import libcore.util.Nullable; 28 29 /** 30 * Provides lifecycle methods and other hooks for an Android runtime "container" to call into the 31 * runtime and core libraries during initialization. For example, from 32 * {@link com.android.internal.os.RuntimeInit}. 33 * 34 * <p>Having a facade class helps to limit the container's knowledge of runtime and core libraries 35 * internal details. All methods assume the container initialization is single threaded. 36 * 37 * @hide 38 */ 39 @SystemApi(client = MODULE_LIBRARIES) 40 @libcore.api.CorePlatformApi(status = libcore.api.CorePlatformApi.Status.STABLE) 41 public final class RuntimeHooks { 42 43 private static Supplier<String> zoneIdSupplier; 44 RuntimeHooks()45 private RuntimeHooks() { 46 // No need to construct an instance. All methods are static. 47 } 48 49 /** 50 * Sets the {@link Supplier} that is used by {@link TimeZone} to retrieve the current time zone 51 * ID iff the cached default is {@code null}. 52 * 53 * <p>This method also clears the current {@link TimeZone} default ensuring that the supplier 54 * will be used next time {@link TimeZone#getDefault()} is called (unless 55 * {@link TimeZone#setDefault(TimeZone)} is called with a non-{@code null} value in the interim). 56 * 57 * <p>Once set the supplier cannot be changed. 58 * 59 * @param zoneIdSupplier new {@link Supplier} of the time zone ID 60 * 61 * @hide 62 */ 63 @SystemApi(client = MODULE_LIBRARIES) 64 @libcore.api.CorePlatformApi(status = libcore.api.CorePlatformApi.Status.STABLE) setTimeZoneIdSupplier(@onNull Supplier<String> zoneIdSupplier)65 public static void setTimeZoneIdSupplier(@NonNull Supplier<String> zoneIdSupplier) { 66 if (RuntimeHooks.zoneIdSupplier != null) { 67 throw new UnsupportedOperationException("zoneIdSupplier instance already set"); 68 } 69 RuntimeHooks.zoneIdSupplier = Objects.requireNonNull(zoneIdSupplier); 70 TimeZone.setDefault(null); 71 } 72 73 /** 74 * Returns the {@link Supplier} that should be used to discover the time zone. 75 * 76 * @hide 77 */ getTimeZoneIdSupplier()78 public static Supplier<String> getTimeZoneIdSupplier() { 79 return RuntimeHooks.zoneIdSupplier; 80 } 81 82 /** 83 * Sets an {@link Thread.UncaughtExceptionHandler} that will be called before any 84 * returned by {@link Thread#getUncaughtExceptionHandler()}. To allow the standard 85 * handlers to run, this handler should never terminate this process. Any 86 * throwables thrown by the handler will be ignored by 87 * {@link Thread#dispatchUncaughtException(Throwable)}. 88 * 89 * @param uncaughtExceptionHandler handler for uncaught exceptions 90 * 91 * @hide 92 */ 93 @SystemApi(client = MODULE_LIBRARIES) 94 @libcore.api.CorePlatformApi(status = libcore.api.CorePlatformApi.Status.STABLE) setUncaughtExceptionPreHandler( @ullable Thread.UncaughtExceptionHandler uncaughtExceptionHandler)95 public static void setUncaughtExceptionPreHandler( 96 @Nullable Thread.UncaughtExceptionHandler uncaughtExceptionHandler) { 97 Thread.setUncaughtExceptionPreHandler(uncaughtExceptionHandler); 98 } 99 } 100