| /* |
| * Copyright 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 androidx.camera.core.impl.utils.executor; |
| |
| import android.os.Handler; |
| import android.os.Looper; |
| |
| import androidx.annotation.NonNull; |
| |
| import java.util.concurrent.Executor; |
| import java.util.concurrent.ScheduledExecutorService; |
| |
| /** |
| * Utility class for generating specific implementations of {@link Executor}. |
| */ |
| public final class CameraXExecutors { |
| |
| // Should not be instantiated |
| private CameraXExecutors() { |
| } |
| |
| /** Returns a cached {@link ScheduledExecutorService} which posts to the main thread. */ |
| @NonNull |
| public static ScheduledExecutorService mainThreadExecutor() { |
| return MainThreadExecutor.getInstance(); |
| } |
| |
| /** Returns a cached {@link Executor} suitable for disk I/O. */ |
| @NonNull |
| public static Executor ioExecutor() { |
| return IoExecutor.getInstance(); |
| } |
| |
| /** Returns a cached executor that runs tasks directly from the calling thread. */ |
| @NonNull |
| public static Executor directExecutor() { |
| return DirectExecutor.getInstance(); |
| } |
| |
| /** |
| * Returns a new executor which will perform all tasks sequentially. |
| * |
| * <p>The returned executor delegates all tasks to the provided delegate Executor, but will |
| * ensure all tasks are run in order and without overlapping. Note this can only be |
| * guaranteed for tasks that are submitted via the same sequential executor. Tasks submitted |
| * directly to the delegate or to different instances of the sequential executor do not have |
| * any ordering guarantees. |
| */ |
| @NonNull |
| public static Executor newSequentialExecutor(@NonNull Executor delegate) { |
| return new SequentialExecutor(delegate); |
| } |
| |
| /** |
| * Returns whether the executor is a sequential executor as returned by |
| * {@link #newSequentialExecutor(Executor)}. |
| */ |
| public static boolean isSequentialExecutor(@NonNull Executor executor) { |
| return executor instanceof SequentialExecutor; |
| } |
| |
| /** |
| * Returns an executor which posts to the thread's current {@link Looper}. |
| * |
| * @return An executor which posts to the thread's current looper. |
| * @throws IllegalStateException if the current thread does not have a looper. |
| */ |
| @NonNull |
| public static ScheduledExecutorService myLooperExecutor() { |
| return HandlerScheduledExecutorService.currentThreadExecutor(); |
| } |
| |
| /** |
| * Returns an executor which posts to the given {@link Handler}. |
| * |
| * @return An executor which posts to the given handler. |
| */ |
| @NonNull |
| public static ScheduledExecutorService newHandlerExecutor(@NonNull Handler handler) { |
| return new HandlerScheduledExecutorService(handler); |
| } |
| |
| /** |
| * @return a cached high priority {@link Executor} suitable for lightweight tasks. |
| */ |
| @NonNull |
| public static Executor highPriorityExecutor() { |
| return HighPriorityExecutor.getInstance(); |
| } |
| } |