ARTEMIS-507 New thread pool for client threads

- Added a thread pool executor, that combines cached and fixed size thread pooling.
  It behaves like a cached thread pool in that it reuses exising threads and removes
  idle threads after a timeout, limits the maximum number of threads in the pool, but
  queue additional request instead of rejecting them.
- changed existing code to use the new thread pool instead of a fixed-size thread pool in
  all places that are configured with a client thread pool size.
This commit is contained in:
Bernd Gutjahr 2016-04-25 15:30:42 +02:00 committed by Martyn Taylor
parent d5ebe071a0
commit 1591d25692
5 changed files with 115 additions and 6 deletions

View File

@ -0,0 +1,109 @@
/*
* 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.activemq.artemis.utils;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
/*
* ActiveMQThreadPoolExecutor: a special ThreadPoolExecutor that combines
* the benefits of a cached executor and a fixed size executor.
* Similar to a cached executor, threads exceeding the core size are only created on demand,
* and will be removed after idling for a specified keep time.
* But in contrast to a standard cached executor, tasks are queued if the
* maximum pool size if reached, instead of rejected.
*
* This is achieved by using a specialized blocking queue, which checks the
* state of the associated executor in the offer method to decide whether to
* queue a task or have the executor create another thread.
*
* Since the thread pool's execute method is reentrant, more than one caller
* could try to offer a task into the queue. There is a small chance that
* (a few) more threads are created as it should be limited by max pool size.
* To allow for such a case not to reject a task, the underlying thread pool
* executor is not limited. Only the offer method checks the configured limit.
*/
public class ActiveMQThreadPoolExecutor extends ThreadPoolExecutor {
@SuppressWarnings("serial")
private static class ThreadPoolQueue extends LinkedBlockingQueue<Runnable> {
private ActiveMQThreadPoolExecutor executor = null;
public void setExecutor(ActiveMQThreadPoolExecutor executor) {
this.executor = executor;
}
@Override
public boolean offer(Runnable runnable) {
int poolSize = executor.getPoolSize();
// If the are less threads than the configured maximum, then the tasks is
// only queued if there are some idle threads that can run that tasks.
// We have to add the queue size, since some tasks might just have been queued
// but not yet taken by an idle thread.
if (poolSize < executor.getMaximumPoolSize() && (size() + executor.getActive()) >= poolSize)
return false;
return super.offer(runnable);
}
}
private int maxPoolSize;
// count the active threads with before-/afterExecute, since the .getActiveCount is not very
// efficient.
private final AtomicInteger active = new AtomicInteger(0);
public ActiveMQThreadPoolExecutor(int coreSize, int maxSize, long keep, TimeUnit keepUnits, ThreadFactory factory) {
this(coreSize, maxSize, keep, keepUnits, new ThreadPoolQueue(), factory);
}
// private constructor is needed to inject 'this' into the ThreadPoolQueue instance
private ActiveMQThreadPoolExecutor(int coreSize, int maxSize, long keep, TimeUnit keepUnits, ThreadPoolQueue myQueue, ThreadFactory factory) {
super(coreSize, Integer.MAX_VALUE, keep, keepUnits, myQueue, factory);
maxPoolSize = maxSize;
myQueue.setExecutor(this);
}
private int getActive() {
return active.get();
}
@Override
public int getMaximumPoolSize() {
return maxPoolSize;
}
@Override
public void setMaximumPoolSize(int maxSize) {
maxPoolSize = maxSize;
}
@Override
protected void beforeExecute(Thread thread, Runnable runnable) {
super.beforeExecute(thread, runnable);
active.incrementAndGet();
}
@Override
protected void afterExecute(Runnable runnable, Throwable throwable) {
active.decrementAndGet();
super.afterExecute(runnable, throwable);
}
}

View File

@ -20,7 +20,6 @@ import java.net.URI;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.SynchronousQueue;
@ -38,6 +37,7 @@ import org.apache.activemq.artemis.core.client.impl.ClientSessionFactoryImpl;
import org.apache.activemq.artemis.core.client.impl.ServerLocatorImpl;
import org.apache.activemq.artemis.uri.ServerLocatorParser;
import org.apache.activemq.artemis.utils.ActiveMQThreadFactory;
import org.apache.activemq.artemis.utils.ActiveMQThreadPoolExecutor;
/**
* Utility class for creating ActiveMQ Artemis {@link ClientSessionFactory} objects.
@ -222,7 +222,7 @@ public final class ActiveMQClient {
globalThreadPool = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), factory);
}
else {
globalThreadPool = new ThreadPoolExecutor(ActiveMQClient.globalThreadPoolSize, ActiveMQClient.globalThreadPoolSize, 1L, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>(), factory);
globalThreadPool = new ActiveMQThreadPoolExecutor(0, ActiveMQClient.globalThreadPoolSize, 60L, TimeUnit.SECONDS, factory);
}
}
return globalThreadPool;

View File

@ -64,6 +64,7 @@ import org.apache.activemq.artemis.spi.core.remoting.ClientProtocolManagerFactor
import org.apache.activemq.artemis.spi.core.remoting.Connector;
import org.apache.activemq.artemis.uri.ServerLocatorParser;
import org.apache.activemq.artemis.utils.ActiveMQThreadFactory;
import org.apache.activemq.artemis.utils.ActiveMQThreadPoolExecutor;
import org.apache.activemq.artemis.utils.ClassloadingUtil;
import org.apache.activemq.artemis.utils.UUIDGenerator;
import org.apache.activemq.artemis.utils.uri.FluentPropertyBeanIntrospectorWithIgnores;
@ -236,7 +237,7 @@ public final class ServerLocatorImpl implements ServerLocatorInternal, Discovery
threadPool = Executors.newCachedThreadPool(factory);
}
else {
threadPool = Executors.newFixedThreadPool(threadPoolMaxSize, factory);
threadPool = new ActiveMQThreadPoolExecutor(0, threadPoolMaxSize, 60L, TimeUnit.SECONDS, factory);
}
factory = AccessController.doPrivileged(new PrivilegedAction<ThreadFactory>() {

View File

@ -221,8 +221,6 @@ public class ClientThreadPoolsTest {
ScheduledThreadPoolExecutor scheduledThreadPool = (ScheduledThreadPoolExecutor) scheduledThreadPoolField.get(serverLocator);
// TODO: We need to figure out what to do with getCorePoolSize
assertEquals(expectedMax, threadPool.getCorePoolSize());
assertEquals(expectedMax, threadPool.getMaximumPoolSize());
assertEquals(expectedScheduled, scheduledThreadPool.getCorePoolSize());
}

View File

@ -41,6 +41,7 @@ import org.apache.activemq.artemis.spi.core.remoting.ClientConnectionLifeCycleLi
import org.apache.activemq.artemis.spi.core.remoting.ClientProtocolManager;
import org.apache.activemq.artemis.spi.core.remoting.Connection;
import org.apache.activemq.artemis.spi.core.remoting.ConnectionLifeCycleListener;
import org.apache.activemq.artemis.utils.ActiveMQThreadPoolExecutor;
import org.apache.activemq.artemis.utils.ConfigurationHelper;
import org.apache.activemq.artemis.utils.OrderedExecutorFactory;
@ -107,7 +108,7 @@ public class InVMConnector extends AbstractConnector {
threadPoolExecutor = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), Executors.defaultThreadFactory());
}
else {
threadPoolExecutor = Executors.newFixedThreadPool(ActiveMQClient.getGlobalThreadPoolSize());
threadPoolExecutor = new ActiveMQThreadPoolExecutor(0, ActiveMQClient.getGlobalThreadPoolSize(), 60L, TimeUnit.SECONDS, Executors.defaultThreadFactory());
}
}
return threadPoolExecutor;