| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.providers.media.util; |
| |
| import android.os.Handler; |
| import android.os.HandlerThread; |
| |
| import java.util.concurrent.CountDownLatch; |
| import java.util.concurrent.Executor; |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * Thread for asynchronous event processing. This thread is configured as |
| * {@link android.os.Process#THREAD_PRIORITY_FOREGROUND}, which means more CPU |
| * resources will be dedicated to it, and it will be treated like "a user |
| * interface that the user is interacting with." |
| * <p> |
| * This thread is best suited for tasks that the user is actively waiting for, |
| * or for tasks that the user expects to be executed immediately. |
| * |
| * @see BackgroundThread |
| */ |
| public final class ForegroundThread extends HandlerThread { |
| private static ForegroundThread sInstance; |
| private static Handler sHandler; |
| private static HandlerExecutor sHandlerExecutor; |
| |
| private ForegroundThread() { |
| super("fg", android.os.Process.THREAD_PRIORITY_FOREGROUND); |
| } |
| |
| private static void ensureThreadLocked() { |
| if (sInstance == null) { |
| sInstance = new ForegroundThread(); |
| sInstance.start(); |
| sHandler = new Handler(sInstance.getLooper()); |
| sHandlerExecutor = new HandlerExecutor(sHandler); |
| } |
| } |
| |
| public static ForegroundThread get() { |
| synchronized (ForegroundThread.class) { |
| ensureThreadLocked(); |
| return sInstance; |
| } |
| } |
| |
| public static Handler getHandler() { |
| synchronized (ForegroundThread.class) { |
| ensureThreadLocked(); |
| return sHandler; |
| } |
| } |
| |
| public static Executor getExecutor() { |
| synchronized (ForegroundThread.class) { |
| ensureThreadLocked(); |
| return sHandlerExecutor; |
| } |
| } |
| |
| public static void waitForIdle() { |
| final CountDownLatch latch = new CountDownLatch(1); |
| getExecutor().execute(() -> { |
| latch.countDown(); |
| }); |
| try { |
| latch.await(30, TimeUnit.SECONDS); |
| } catch (InterruptedException e) { |
| throw new IllegalStateException(e); |
| } |
| } |
| } |