| /* |
| * Copyright (C) 2011 The Guava Authors |
| * |
| * 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.google.common.util.concurrent; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| import static com.google.common.base.Throwables.throwIfUnchecked; |
| |
| import com.google.common.annotations.GwtIncompatible; |
| import com.google.common.collect.ImmutableList; |
| import com.google.errorprone.annotations.CanIgnoreReturnValue; |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.concurrent.Callable; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.Future; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.TimeoutException; |
| |
| /** |
| * An abstract {@code ExecutorService} that allows subclasses to {@linkplain #wrapTask(Callable) |
| * wrap} tasks before they are submitted to the underlying executor. |
| * |
| * <p>Note that task wrapping may occur even if the task is never executed. |
| * |
| * <p>For delegation without task-wrapping, see {@link ForwardingExecutorService}. |
| * |
| * @author Chris Nokleberg |
| */ |
| @CanIgnoreReturnValue // TODO(cpovirk): Consider being more strict. |
| @GwtIncompatible |
| abstract class WrappingExecutorService implements ExecutorService { |
| private final ExecutorService delegate; |
| |
| protected WrappingExecutorService(ExecutorService delegate) { |
| this.delegate = checkNotNull(delegate); |
| } |
| |
| /** |
| * Wraps a {@code Callable} for submission to the underlying executor. This method is also applied |
| * to any {@code Runnable} passed to the default implementation of {@link #wrapTask(Runnable)}. |
| */ |
| protected abstract <T> Callable<T> wrapTask(Callable<T> callable); |
| |
| /** |
| * Wraps a {@code Runnable} for submission to the underlying executor. The default implementation |
| * delegates to {@link #wrapTask(Callable)}. |
| */ |
| protected Runnable wrapTask(Runnable command) { |
| final Callable<Object> wrapped = wrapTask(Executors.callable(command, null)); |
| return new Runnable() { |
| @Override |
| public void run() { |
| try { |
| wrapped.call(); |
| } catch (Exception e) { |
| throwIfUnchecked(e); |
| throw new RuntimeException(e); |
| } |
| } |
| }; |
| } |
| |
| /** |
| * Wraps a collection of tasks. |
| * |
| * @throws NullPointerException if any element of {@code tasks} is null |
| */ |
| private <T> ImmutableList<Callable<T>> wrapTasks(Collection<? extends Callable<T>> tasks) { |
| ImmutableList.Builder<Callable<T>> builder = ImmutableList.builder(); |
| for (Callable<T> task : tasks) { |
| builder.add(wrapTask(task)); |
| } |
| return builder.build(); |
| } |
| |
| // These methods wrap before delegating. |
| @Override |
| public final void execute(Runnable command) { |
| delegate.execute(wrapTask(command)); |
| } |
| |
| @Override |
| public final <T> Future<T> submit(Callable<T> task) { |
| return delegate.submit(wrapTask(checkNotNull(task))); |
| } |
| |
| @Override |
| public final Future<?> submit(Runnable task) { |
| return delegate.submit(wrapTask(task)); |
| } |
| |
| @Override |
| public final <T> Future<T> submit(Runnable task, T result) { |
| return delegate.submit(wrapTask(task), result); |
| } |
| |
| @Override |
| public final <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) |
| throws InterruptedException { |
| return delegate.invokeAll(wrapTasks(tasks)); |
| } |
| |
| @Override |
| public final <T> List<Future<T>> invokeAll( |
| Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) |
| throws InterruptedException { |
| return delegate.invokeAll(wrapTasks(tasks), timeout, unit); |
| } |
| |
| @Override |
| public final <T> T invokeAny(Collection<? extends Callable<T>> tasks) |
| throws InterruptedException, ExecutionException { |
| return delegate.invokeAny(wrapTasks(tasks)); |
| } |
| |
| @Override |
| public final <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) |
| throws InterruptedException, ExecutionException, TimeoutException { |
| return delegate.invokeAny(wrapTasks(tasks), timeout, unit); |
| } |
| |
| // The remaining methods just delegate. |
| |
| @Override |
| public final void shutdown() { |
| delegate.shutdown(); |
| } |
| |
| @Override |
| public final List<Runnable> shutdownNow() { |
| return delegate.shutdownNow(); |
| } |
| |
| @Override |
| public final boolean isShutdown() { |
| return delegate.isShutdown(); |
| } |
| |
| @Override |
| public final boolean isTerminated() { |
| return delegate.isTerminated(); |
| } |
| |
| @Override |
| public final boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException { |
| return delegate.awaitTermination(timeout, unit); |
| } |
| } |