/*
* Copyright (c) 2009-2014, toby weston & tempus-fugit committers
*
* 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.code.tempusfugit.concurrency;
import com.google.code.tempusfugit.temporal.Clock;
import com.google.code.tempusfugit.temporal.Duration;
import com.google.code.tempusfugit.temporal.RealClock;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.*;
import static com.google.code.tempusfugit.concurrency.Interrupter.interrupt;
import static com.google.code.tempusfugit.temporal.Duration.seconds;
import static java.lang.Thread.currentThread;
public class DefaultTimeoutableCompletionService implements TimeoutableCompletionService {
private static final boolean INTERRUPT_IF_RUNNING = true;
private static final Duration DEFAULT_TIMEOUT = seconds(30);
private final java.util.concurrent.CompletionService completionService;
private final Duration timeout;
private final Clock time;
public DefaultTimeoutableCompletionService(CompletionService completionService) {
this(completionService, DEFAULT_TIMEOUT, new RealClock());
}
public DefaultTimeoutableCompletionService(CompletionService completionService, Duration timeout, Clock time) {
this.timeout = timeout;
this.time = time;
this.completionService = completionService;
}
public <T> List<T> submit(List<? extends java.util.concurrent.Callable<T>> tasks) throws ExecutionException, TimeoutException {
List<Future<T>> submitted = new ArrayList<Future<T>>();
try {
for (Callable task : tasks) {
submitted.add(completionService.submit(task));
}
return waitFor(tasks.size(), timeout);
} finally {
for (Future<T> future : submitted) {
future.cancel(INTERRUPT_IF_RUNNING);
}
}
}
private <T> List<T> waitFor(int tasks, Duration timeout) throws ExecutionException, TimeoutException {
List<T> completed = new ArrayList<T>();
Interrupter interrupter = interrupt(currentThread()).using(time).after(timeout);
try {
for (int i = 0; i < tasks; i++) {
try {
Future<T> future = completionService.take();
completed.add(future.get());
} catch (InterruptedException e) {
throw new TimeoutExceptionWithResults("timed out after " + timeout.toString(), completed);
}
}
} finally {
interrupter.cancel();
}
return completed;
}
}