/*
* 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.jmeter.timers;
import java.io.Serializable;
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.apache.jmeter.testbeans.TestBean;
import org.apache.jmeter.testelement.AbstractTestElement;
import org.apache.jmeter.testelement.TestStateListener;
import org.apache.jmeter.testelement.ThreadListener;
import org.apache.jmeter.threads.JMeterContextService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The purpose of the SyncTimer is to block threads until X number of threads
* have been blocked, and then they are all released at once. A SyncTimer can
* thus create large instant loads at various points of the test plan.
*
*/
public class SyncTimer extends AbstractTestElement implements Timer, Serializable, TestBean, TestStateListener, ThreadListener {
private static final Logger log = LoggerFactory.getLogger(SyncTimer.class);
/**
* Wrapper to {@link CyclicBarrier} to allow lazy init of CyclicBarrier when SyncTimer is configured with 0
*/
private static class BarrierWrapper implements Cloneable {
private CyclicBarrier barrier;
/**
*
*/
public BarrierWrapper() {
this.barrier = null;
}
/**
* @param parties Number of parties
*/
public BarrierWrapper(int parties) {
this.barrier = new CyclicBarrier(parties);
}
/**
* Synchronized is required to ensure CyclicBarrier is initialized only once per Thread Group
* @param parties Number of parties
*/
public synchronized void setup(int parties) {
if(this.barrier== null) {
this.barrier = new CyclicBarrier(parties);
}
}
/**
* Wait until all threads called await on this timer
*
* @return The arrival index of the current thread
* @throws InterruptedException
* when interrupted while waiting, or the interrupted status
* is set on entering this method
* @throws BrokenBarrierException
* if the barrier is reset while waiting or broken on
* entering or while waiting
* @see java.util.concurrent.CyclicBarrier#await()
*/
public int await() throws InterruptedException, BrokenBarrierException{
return barrier.await();
}
/**
* Wait until all threads called await on this timer
*
* @param timeout
* The timeout in <code>timeUnit</code> units
* @param timeUnit
* The time unit for the <code>timeout</code>
* @return The arrival index of the current thread
* @throws InterruptedException
* when interrupted while waiting, or the interrupted status
* is set on entering this method
* @throws BrokenBarrierException
* if the barrier is reset while waiting or broken on
* entering or while waiting
* @throws TimeoutException
* if the specified time elapses
* @see java.util.concurrent.CyclicBarrier#await()
*/
public int await(long timeout, TimeUnit timeUnit) throws InterruptedException, BrokenBarrierException, TimeoutException {
return barrier.await(timeout, timeUnit);
}
/**
* @see java.util.concurrent.CyclicBarrier#reset()
*/
public void reset() {
barrier.reset();
}
/**
* @see java.lang.Object#clone()
*/
@Override
protected Object clone() {
BarrierWrapper barrierWrapper= null;
try {
barrierWrapper = (BarrierWrapper) super.clone();
barrierWrapper.barrier = this.barrier;
} catch (CloneNotSupportedException e) {
//Cannot happen
}
return barrierWrapper;
}
}
private static final long serialVersionUID = 3;
private transient BarrierWrapper barrier;
private int groupSize;
private long timeoutInMs;
// Ensure transient object is created by the server
private Object readResolve(){
createBarrier();
return this;
}
/**
* @return Returns the numThreads.
*/
public int getGroupSize() {
return groupSize;
}
/**
* @param numThreads
* The numThreads to set.
*/
public void setGroupSize(int numThreads) {
this.groupSize = numThreads;
}
/**
* {@inheritDoc}
*/
@Override
public long delay() {
if(getGroupSize()>=0) {
int arrival = 0;
try {
if(timeoutInMs==0) {
arrival = this.barrier.await();
} else if(timeoutInMs > 0){
arrival = this.barrier.await(timeoutInMs, TimeUnit.MILLISECONDS);
} else {
throw new IllegalArgumentException("Negative value for timeout:"+timeoutInMs+" in Synchronizing Timer "+getName());
}
} catch (InterruptedException | BrokenBarrierException e) {
return 0;
} catch (TimeoutException e) {
if (log.isWarnEnabled()) {
log.warn("SyncTimer {} timeouted waiting for users after: {}ms", getName(), getTimeoutInMs());
}
return 0;
} finally {
if(arrival == 0) {
barrier.reset();
}
}
}
return 0;
}
/**
* We have to control the cloning process because we need some cross-thread
* communication if our synctimers are to be able to determine when to block
* and when to release.
*/
@Override
public Object clone() {
SyncTimer newTimer = (SyncTimer) super.clone();
newTimer.barrier = barrier;
return newTimer;
}
/**
* {@inheritDoc}
*/
@Override
public void testEnded() {
this.testEnded(null);
}
/**
* Reset timerCounter
*/
@Override
public void testEnded(String host) {
createBarrier();
}
/**
* {@inheritDoc}
*/
@Override
public void testStarted() {
testStarted(null);
}
/**
* Reset timerCounter
*/
@Override
public void testStarted(String host) {
createBarrier();
}
/**
*
*/
private void createBarrier() {
if(getGroupSize() == 0) {
// Lazy init
this.barrier = new BarrierWrapper();
} else {
this.barrier = new BarrierWrapper(getGroupSize());
}
}
@Override
public void threadStarted() {
if(getGroupSize() == 0) {
int numThreadsInGroup = JMeterContextService.getContext().getThreadGroup().getNumThreads();
// Unique Barrier creation ensured by synchronized setup
this.barrier.setup(numThreadsInGroup);
}
}
@Override
public void threadFinished() {
// NOOP
}
/**
* @return the timeoutInMs
*/
public long getTimeoutInMs() {
return timeoutInMs;
}
/**
* @param timeoutInMs the timeoutInMs to set
*/
public void setTimeoutInMs(long timeoutInMs) {
this.timeoutInMs = timeoutInMs;
}
}