org.eclipse.aether.util.concurrency.ExecutorUtils Maven / Gradle / Ivy
/*
* 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.eclipse.aether.util.concurrency;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.util.ConfigUtils;
/**
* Utilities for executors and sizing them.
*
* @since 1.9.5
*/
public final class ExecutorUtils {
/**
* Shared instance of "direct executor".
*/
public static final Executor DIRECT_EXECUTOR = Runnable::run;
/**
* Creates new thread pool {@link ExecutorService}. The {@code poolSize} parameter but be greater than 1.
*/
public static ExecutorService threadPool(int poolSize, String namePrefix) {
if (poolSize < 2) {
throw new IllegalArgumentException("Invalid poolSize: " + poolSize + ". Must be greater than 1.");
}
return new ThreadPoolExecutor(
poolSize,
poolSize,
3L,
TimeUnit.SECONDS,
new LinkedBlockingQueue<>(),
new WorkerThreadFactory(namePrefix));
}
/**
* Returns {@link #DIRECT_EXECUTOR} or result of {@link #threadPool(int, String)} depending on value of
* {@code size} parameter.
*/
public static Executor executor(int size, String namePrefix) {
if (size <= 1) {
return DIRECT_EXECUTOR;
} else {
return threadPool(size, namePrefix);
}
}
/**
* To be used with result of {@link #executor(int, String)} method, shuts down instance if it is
* {@link ExecutorService}.
*/
public static void shutdown(Executor executor) {
if (executor instanceof ExecutorService) {
((ExecutorService) executor).shutdown();
}
}
/**
* Retrieves and validates requested thread count based on session and specified keys, or if none provided, the
* provided default value. This method validates result on top of what {@link ConfigUtils} does.
*
* @throws IllegalArgumentException if default value is less than 1.
* @see ConfigUtils#getInteger(RepositorySystemSession, int, String...)
*/
public static int threadCount(RepositorySystemSession session, int defaultValue, String... keys) {
if (defaultValue < 1) {
throw new IllegalArgumentException("Invalid defaultValue: " + defaultValue + ". Must be greater than 0.");
}
int threadCount = ConfigUtils.getInteger(session, defaultValue, keys);
if (threadCount < 1) {
throw new IllegalArgumentException("Invalid value: " + threadCount + ". Must be greater than 0.");
}
return threadCount;
}
}