org.jgrapht.util.ConcurrencyUtil Maven / Gradle / Ivy
/*
* (C) Copyright 2020-2021, by Semen Chudakov and Contributors.
*
* JGraphT : a free Java graph-theory library
*
* See the CONTRIBUTORS.md file distributed with this work for additional
* information regarding copyright ownership.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0, or the
* GNU Lesser General Public License v2.1 or later
* which is available at
* http://www.gnu.org/licenses/old-licenses/lgpl-2.1-standalone.html.
*
* SPDX-License-Identifier: EPL-2.0 OR LGPL-2.1-or-later
*/
package org.jgrapht.util;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
/**
* Utility class to manage creation and shutting down instance of the {@link ThreadPoolExecutor}.
*/
public class ConcurrencyUtil
{
/**
* Creates a {@link ThreadPoolExecutor} with fixed number of threads which is equal to
* {@code parallelism}.
*
* @param parallelism number of threads for the executor
* @return created executor
*/
public static ThreadPoolExecutor createThreadPoolExecutor(int parallelism)
{
return (ThreadPoolExecutor) Executors.newFixedThreadPool(parallelism);
}
/**
* Shuts down the {@code executor}. This operation puts the {@code service} into a state where
* every subsequent task submitted to the {@code service} will be rejected. This method calls
* {@link #shutdownExecutionService(ExecutorService, long, TimeUnit)} with $time =
* Long.MAX_VALUE$ and $timeUnit = TimeUnit.MILLISECONDS$.
*
* @param service service to be shut down
*/
public static void shutdownExecutionService(ExecutorService service)
throws InterruptedException
{
shutdownExecutionService(service, Long.MAX_VALUE, TimeUnit.MILLISECONDS);
}
/**
* Shuts down the {@code executor}. This operation puts the {@code service} into a state where
* every subsequent task submitted to the {@code service} will be rejected.
*
* @param service service to be shut down
* @param time period of time to wait for the completion of the termination
* @param timeUnit time duration granularity for the provided {@code time}
*/
public static void shutdownExecutionService(
ExecutorService service, long time, TimeUnit timeUnit)
throws InterruptedException
{
service.shutdown();
service.awaitTermination(time, timeUnit);
}
}