/*
* 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 org.elasticsearch.common.settings.Setting;
import org.elasticsearch.common.settings.Setting.Property;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.node.Node;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.AbstractExecutorService;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.LinkedTransferQueue;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.stream.Collectors;
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 Setting<Integer> PROCESSORS_SETTING =
Setting.intSetting("processors", Runtime.getRuntime().availableProcessors(), 1, Property.NodeScope);
/**
* Returns the number of available processors. Defaults to
* {@link Runtime#availableProcessors()} but can be overridden by passing a {@link Settings}
* instance with the key "processors" set to the desired value.
*
* @param settings a {@link Settings} instance from which to derive the available processors
* @return the number of available processors
*/
public static int numberOfProcessors(final Settings settings) {
return PROCESSORS_SETTING.get(settings);
}
public static PrioritizedEsThreadPoolExecutor newSinglePrioritizing(String name, ThreadFactory threadFactory, ThreadContext contextHolder, ScheduledExecutorService timer) {
return new PrioritizedEsThreadPoolExecutor(name, 1, 1, 0L, TimeUnit.MILLISECONDS, threadFactory, contextHolder, timer);
}
public static EsThreadPoolExecutor newScaling(String name, int min, int max, long keepAliveTime, TimeUnit unit, ThreadFactory threadFactory, ThreadContext contextHolder) {
ExecutorScalingQueue<Runnable> queue = new ExecutorScalingQueue<>();
EsThreadPoolExecutor executor = new EsThreadPoolExecutor(name, min, max, keepAliveTime, unit, queue, threadFactory, new ForceQueuePolicy(), contextHolder);
queue.executor = executor;
return executor;
}
public static EsThreadPoolExecutor newFixed(String name, int size, int queueCapacity, ThreadFactory threadFactory, ThreadContext contextHolder) {
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(), contextHolder);
}
private static final ExecutorService DIRECT_EXECUTOR_SERVICE = new AbstractExecutorService() {
@Override
public void shutdown() {
throw new UnsupportedOperationException();
}
@Override
public List<Runnable> shutdownNow() {
throw new UnsupportedOperationException();
}
@Override
public boolean isShutdown() {
return false;
}
@Override
public boolean isTerminated() {
return false;
}
@Override
public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
throw new UnsupportedOperationException();
}
@Override
public void execute(Runnable command) {
command.run();
}
};
/**
* Returns an {@link ExecutorService} that executes submitted tasks on the current thread. This executor service does not support being
* shutdown.
*
* @return an {@link ExecutorService} that executes submitted tasks on the current thread
*/
public static ExecutorService newDirectExecutorService() {
return DIRECT_EXECUTOR_SERVICE;
}
public static String threadName(Settings settings, String ... names) {
String namePrefix =
Arrays
.stream(names)
.filter(name -> name != null)
.collect(Collectors.joining(".", "[", "]"));
return threadName(settings, namePrefix);
}
public static String threadName(Settings settings, String namePrefix) {
if (Node.NODE_NAME_SETTING.exists(settings)) {
return threadName(Node.NODE_NAME_SETTING.get(settings), namePrefix);
} else {
return threadName("", namePrefix);
}
}
public static String threadName(final String nodeName, final String namePrefix) {
return "elasticsearch" + (nodeName.isEmpty() ? "" : "[") + nodeName + (nodeName.isEmpty() ? "" : "]") + "[" + 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;
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;
ExecutorScalingQueue() {
}
@Override
public boolean offer(E e) {
// first try to transfer to a waiting worker thread
if (!tryTransfer(e)) {
// check if there might be spare capacity in the thread
// pool executor
int left = executor.getMaximumPoolSize() - executor.getCorePoolSize();
if (left > 0) {
// reject queuing the task to force the thread pool
// executor to add a worker if it can; combined
// with ForceQueuePolicy, this causes the thread
// pool to always scale up to max pool size and we
// only queue when there is no spare capacity
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;
}
}
}