/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.common.util.concurrent;
import com.google.common.base.Joiner;
import org.elasticsearch.common.settings.Settings;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;
/**
*
*/
public class EsExecutors {
/**
* Settings key to manually set the number of available processors.
* This is used to adjust thread pools sizes etc. per node.
*/
public static final String PROCESSORS = "processors";
/** Useful for testing */
public static final String DEFAULT_SYSPROP = "es.processors.override";
/**
* Returns the number of processors available but at most <tt>32</tt>.
*/
public static int boundedNumberOfProcessors(Settings settings) {
/* This relates to issues where machines with large number of cores
* ie. >= 48 create too many threads and run into OOM see #3478
* We just use an 32 core upper-bound here to not stress the system
* too much with too many created threads */
int defaultValue = Math.min(32, Runtime.getRuntime().availableProcessors());
try {
defaultValue = Integer.parseInt(System.getProperty(DEFAULT_SYSPROP));
} catch (Throwable ignored) {}
return settings.getAsInt(PROCESSORS, defaultValue);
}
public static PrioritizedEsThreadPoolExecutor newSinglePrioritizing(String name, ThreadFactory threadFactory) {
return new PrioritizedEsThreadPoolExecutor(name, 1, 1, 0L, TimeUnit.MILLISECONDS, threadFactory);
}
public static EsThreadPoolExecutor newScaling(String name, int min, int max, long keepAliveTime, TimeUnit unit, ThreadFactory threadFactory) {
ExecutorScalingQueue<Runnable> queue = new ExecutorScalingQueue<>();
// we force the execution, since we might run into concurrency issues in offer for ScalingBlockingQueue
EsThreadPoolExecutor executor = new EsThreadPoolExecutor(name, min, max, keepAliveTime, unit, queue, threadFactory, new ForceQueuePolicy());
queue.executor = executor;
return executor;
}
public static EsThreadPoolExecutor newCached(String name, long keepAliveTime, TimeUnit unit, ThreadFactory threadFactory) {
return new EsThreadPoolExecutor(name, 0, Integer.MAX_VALUE, keepAliveTime, unit, new SynchronousQueue<Runnable>(), threadFactory, new EsAbortPolicy());
}
public static EsThreadPoolExecutor newFixed(String name, int size, int queueCapacity, ThreadFactory threadFactory) {
BlockingQueue<Runnable> queue;
if (queueCapacity < 0) {
queue = ConcurrentCollections.newBlockingQueue();
} else {
queue = new SizeBlockingQueue<>(ConcurrentCollections.<Runnable>newBlockingQueue(), queueCapacity);
}
return new EsThreadPoolExecutor(name, size, size, 0, TimeUnit.MILLISECONDS, queue, threadFactory, new EsAbortPolicy());
}
public static String threadName(Settings settings, String ... names) {
return threadName(settings, "[" + Joiner.on(".").skipNulls().join(names) + "]");
}
public static String threadName(Settings settings, String namePrefix) {
String name = settings.get("name");
if (name == null) {
name = "elasticsearch";
} else {
name = "elasticsearch[" + name + "]";
}
return name + "[" + namePrefix + "]";
}
public static ThreadFactory daemonThreadFactory(Settings settings, String namePrefix) {
return daemonThreadFactory(threadName(settings, namePrefix));
}
public static ThreadFactory daemonThreadFactory(Settings settings, String ... names) {
return daemonThreadFactory(threadName(settings, names));
}
public static ThreadFactory daemonThreadFactory(String namePrefix) {
return new EsThreadFactory(namePrefix);
}
static class EsThreadFactory implements ThreadFactory {
final ThreadGroup group;
final AtomicInteger threadNumber = new AtomicInteger(1);
final String namePrefix;
public EsThreadFactory(String namePrefix) {
this.namePrefix = namePrefix;
SecurityManager s = System.getSecurityManager();
group = (s != null) ? s.getThreadGroup() :
Thread.currentThread().getThreadGroup();
}
@Override
public Thread newThread(Runnable r) {
Thread t = new Thread(group, r,
namePrefix + "[T#" + threadNumber.getAndIncrement() + "]",
0);
t.setDaemon(true);
return t;
}
}
/**
* Cannot instantiate.
*/
private EsExecutors() {
}
static class ExecutorScalingQueue<E> extends LinkedTransferQueue<E> {
ThreadPoolExecutor executor;
public ExecutorScalingQueue() {
}
@Override
public boolean offer(E e) {
if (!tryTransfer(e)) {
int left = executor.getMaximumPoolSize() - executor.getCorePoolSize();
if (left > 0) {
return false;
} else {
return super.offer(e);
}
} else {
return true;
}
}
}
/**
* A handler for rejected tasks that adds the specified element to this queue,
* waiting if necessary for space to become available.
*/
static class ForceQueuePolicy implements XRejectedExecutionHandler {
@Override
public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
try {
executor.getQueue().put(r);
} catch (InterruptedException e) {
//should never happen since we never wait
throw new EsRejectedExecutionException(e);
}
}
@Override
public long rejected() {
return 0;
}
}
}