/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.tomcat.util.threads;
import java.util.List;
import java.util.concurrent.AbstractExecutorService;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.TimeUnit;
public class InlineExecutorService extends AbstractExecutorService {
private volatile boolean shutdown;
private volatile boolean taskRunning;
private volatile boolean terminated;
private final Object lock = new Object();
@Override
public void shutdown() {
shutdown = true;
synchronized (lock) {
terminated = !taskRunning;
}
}
@Override
public List<Runnable> shutdownNow() {
shutdown();
return List.of();
}
@Override
public boolean isShutdown() {
return shutdown;
}
@Override
public boolean isTerminated() {
return terminated;
}
@Override
public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
long timeoutExpiry = System.nanoTime() + unit.toNanos(timeout);
long timeoutMillis = unit.toMillis(timeout);
synchronized (lock) {
/*
* Spurious wake-ups are possible. Keep waiting until the service has been terminated or the timeout has
* expired.
*/
while (!terminated && timeoutMillis > 0) {
lock.wait(timeoutMillis);
timeoutMillis = (timeoutExpiry - System.nanoTime()) / 1_000_000;
}
return terminated;
}
}
@Override
public void execute(Runnable command) {
synchronized (lock) {
if (shutdown) {
throw new RejectedExecutionException();
}
taskRunning = true;
}
command.run();
synchronized (lock) {
taskRunning = false;
if (shutdown) {
terminated = true;
lock.notifyAll();
}
}
}
}