org.jboss.threads.QueuelessExecutor Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
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/*
* JBoss, Home of Professional Open Source.
* Copyright 2017 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed 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.jboss.threads;
import java.util.Collections;
import java.util.Date;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.AbstractExecutorService;
import java.util.concurrent.Executor;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.jboss.threads.management.BoundedThreadPoolExecutorMBean;
import org.wildfly.common.Assert;
/**
* A queueless thread pool. If one or more threads are waiting for work when a task is submitted, it will be used.
* Otherwise, if fewer than the maximum threads are started, a new thread is created.
*
* @deprecated Use {@link EnhancedQueueExecutor} instead.
*/
@Deprecated
public final class QueuelessExecutor extends AbstractExecutorService implements BlockingExecutorService, BoundedThreadPoolExecutorMBean, ShutdownListenable {
private final SimpleShutdownListenable shutdownListenable = new SimpleShutdownListenable();
private final ThreadFactory threadFactory;
private final DirectExecutor taskExecutor;
private final Lock lock = new ReentrantLock(false);
private final Condition runnableDequeued = lock.newCondition();
private final Condition nextReady = lock.newCondition();
private final Condition workerDequeued = lock.newCondition();
private final Condition taskEnqueued = lock.newCondition();
private final Condition threadDeath = lock.newCondition();
/**
* Protected by {@link #lock}
*/
private final Set runningThreads = new HashSet(256);
/**
* Protected by {@link #lock}, signal {@link #runnableDequeued} on clear
*/
private Runnable workRunnable;
/**
* Protected by {@link #lock}, signal {@link #workerDequeued} on clear
*/
private Worker waitingWorker;
/**
* Configuration value.
* Protected by {@link #lock}
*/
private long keepAliveTime;
/**
* Configuration value.
* Protected by {@link #lock}
*/
private int maxThreads;
/**
* Specify whether this executor blocks when no threads are available.
* Protected by {@link #lock}
*/
private boolean blocking;
private Executor handoffExecutor;
private boolean stop;
//-- statistics --
private int largestPoolSize;
private int rejectedCount;
public QueuelessExecutor(final ThreadFactory threadFactory, final DirectExecutor taskExecutor, final Executor handoffExecutor, final long keepAliveTime) {
this.threadFactory = threadFactory;
this.taskExecutor = taskExecutor;
this.handoffExecutor = handoffExecutor;
this.keepAliveTime = keepAliveTime;
}
public int getMaxThreads() {
final Lock lock = this.lock;
lock.lock();
try {
return maxThreads;
} finally {
lock.unlock();
}
}
public void setMaxThreads(final int newSize) {
Assert.checkMinimumParameter("newSize", 1, newSize);
final Lock lock = this.lock;
lock.lock();
try {
maxThreads = newSize;
} finally {
lock.unlock();
}
}
public long getKeepAliveTime() {
final Lock lock = this.lock;
lock.lock();
try {
return keepAliveTime;
} finally {
lock.unlock();
}
}
public void setKeepAliveTime(final long milliseconds) {
final Lock lock = this.lock;
lock.lock();
try {
keepAliveTime = milliseconds;
} finally {
lock.unlock();
}
}
public int getCurrentThreadCount() {
final Lock lock = this.lock;
lock.lock();
try {
return runningThreads.size();
} finally {
lock.unlock();
}
}
public int getLargestThreadCount() {
final Lock lock = this.lock;
lock.lock();
try {
return largestPoolSize;
} finally {
lock.unlock();
}
}
public int getRejectedCount() {
final Lock lock = this.lock;
lock.lock();
try {
return rejectedCount;
} finally {
lock.unlock();
}
}
/** {@inheritDoc} */
public int getQueueSize() {
return 0;
}
public boolean isBlocking() {
final Lock lock = this.lock;
lock.lock();
try {
return blocking;
} finally {
lock.unlock();
}
}
public void setBlocking(final boolean blocking) {
final Lock lock = this.lock;
lock.lock();
try {
this.blocking = blocking;
} finally {
lock.unlock();
}
}
public Executor getHandoffExecutor() {
final Lock lock = this.lock;
lock.lock();
try {
return handoffExecutor;
} finally {
lock.unlock();
}
}
public void setHandoffExecutor(final Executor handoffExecutor) {
final Lock lock = this.lock;
lock.lock();
try {
this.handoffExecutor = handoffExecutor;
} finally {
lock.unlock();
}
}
public void shutdown() {
boolean callShutdownListener = false;
final Lock lock = this.lock;
lock.lock();
try {
if (! stop) {
if (runningThreads.isEmpty()) {
callShutdownListener = true;
} else {
for (Thread runningThread : runningThreads) {
runningThread.interrupt();
}
}
}
stop = true;
// wake up all waiters
runnableDequeued.signalAll();
nextReady.signalAll();
workerDequeued.signalAll();
taskEnqueued.signalAll();
} finally {
lock.unlock();
if (callShutdownListener)
shutdownListenable.shutdown();
}
}
public boolean awaitTermination(final long timeout, final TimeUnit unit) throws InterruptedException {
final Lock lock = this.lock;
lock.lock();
try {
if (! stop) {
throw Messages.msg.notShutDown();
}
final Date deadline = new Date(clipHigh(unit.toMillis(timeout) + System.currentTimeMillis()));
final Condition threadDeath = this.threadDeath;
while (! runningThreads.isEmpty() && threadDeath.awaitUntil(deadline));
return runningThreads.isEmpty();
} finally {
lock.unlock();
}
}
public List shutdownNow() {
shutdown();
// tasks are never queued
return Collections.emptyList();
}
public boolean isShutdown() {
final Lock lock = this.lock;
lock.lock();
try {
return stop;
} finally {
lock.unlock();
}
}
public boolean isTerminated() {
final Lock lock = this.lock;
lock.lock();
try {
return stop && runningThreads.isEmpty();
} finally {
lock.unlock();
}
}
public void execute(final Runnable task) {
Assert.checkNotNullParam("task", task);
final Executor executor;
final Set runningThreads = this.runningThreads;
final Condition runnableDequeued = this.runnableDequeued;
final Lock lock = this.lock;
Runnable workRunnable;
lock.lock();
try {
for (;;) {
if (stop) {
throw Messages.msg.shutDownInitiated();
}
final Worker waitingWorker;
if ((waitingWorker = this.waitingWorker) != null) {
// a worker thread was waiting for a task; give it the task and wake it up
waitingWorker.setRunnable(task);
taskEnqueued.signal();
this.waitingWorker = null;
workerDequeued.signal();
return;
}
// no worker thread was waiting
final int currentSize = runningThreads.size();
if (currentSize < maxThreads) {
// if we haven't reached the thread limit yet, start up another thread
final Thread thread = threadFactory.newThread(new Worker(task));
if (thread == null) {
throw Messages.msg.noThreadCreated();
}
if (! runningThreads.add(thread)) {
throw Messages.msg.cannotAddThread();
}
if (currentSize >= largestPoolSize) {
largestPoolSize = currentSize + 1;
}
thread.start();
return;
}
if (! blocking) {
// not blocking, not accepted
executor = handoffExecutor;
rejectedCount++;
// fall out to execute outside of lock
break;
}
workRunnable = this.workRunnable;
if (workRunnable != null) {
// someone else is waiting for a worker, so we wait for them
try {
nextReady.await();
continue;
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw Messages.msg.executionInterrupted();
}
}
this.workRunnable = task;
try {
runnableDequeued.await();
if (this.workRunnable == null) {
// task was accepted
nextReady.signal();
return;
}
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw Messages.msg.executionInterrupted();
} finally {
this.workRunnable = null;
}
}
} finally {
lock.unlock();
}
if (executor != null) {
executor.execute(task);
} else {
throw Messages.msg.executionRejected();
}
}
public void executeBlocking(final Runnable task) throws RejectedExecutionException, InterruptedException {
Assert.checkNotNullParam("task", task);
final Set runningThreads = this.runningThreads;
final Condition runnableDequeued = this.runnableDequeued;
final Lock lock = this.lock;
Runnable workRunnable;
lock.lock();
try {
for (;;) {
if (stop) {
throw Messages.msg.shutDownInitiated();
}
final Worker waitingWorker;
if ((waitingWorker = this.waitingWorker) != null) {
// a worker thread was waiting for a task; give it the task and wake it up
waitingWorker.setRunnable(task);
taskEnqueued.signal();
this.waitingWorker = null;
workerDequeued.signal();
return;
}
// no worker thread was waiting
final int currentSize = runningThreads.size();
if (currentSize < maxThreads) {
// if we haven't reached the thread limit yet, start up another thread
final Thread thread = threadFactory.newThread(new Worker(task));
if (thread == null) {
throw Messages.msg.noThreadCreated();
}
if (! runningThreads.add(thread)) {
throw Messages.msg.cannotAddThread();
}
if (currentSize >= largestPoolSize) {
largestPoolSize = currentSize + 1;
}
thread.start();
return;
}
workRunnable = this.workRunnable;
if (workRunnable != null) {
// someone else is waiting for a worker, so we wait for them
nextReady.await();
continue;
}
this.workRunnable = task;
try {
runnableDequeued.await();
if (this.workRunnable == null) {
// task was accepted
nextReady.signal();
return;
}
} finally {
this.workRunnable = null;
}
}
} finally {
lock.unlock();
}
}
public void executeBlocking(final Runnable task, final long timeout, final TimeUnit unit) throws RejectedExecutionException, InterruptedException {
Assert.checkNotNullParam("task", task);
Assert.checkNotNullParam("unit", unit);
long now = System.currentTimeMillis();
final long deadline = now + unit.toMillis(timeout);
if (deadline < 0L) {
executeBlocking(task);
return;
}
final Set runningThreads = this.runningThreads;
final Condition runnableDequeued = this.runnableDequeued;
final Lock lock = this.lock;
Runnable workRunnable;
lock.lock();
try {
for (;;) {
if (stop) {
throw Messages.msg.shutDownInitiated();
}
final Worker waitingWorker;
if ((waitingWorker = this.waitingWorker) != null) {
// a worker thread was waiting for a task; give it the task and wake it up
waitingWorker.setRunnable(task);
taskEnqueued.signal();
this.waitingWorker = null;
workerDequeued.signal();
return;
}
// no worker thread was waiting
final int currentSize = runningThreads.size();
if (currentSize < maxThreads) {
// if we haven't reached the thread limit yet, start up another thread
final Thread thread = threadFactory.newThread(new Worker(task));
if (thread == null) {
throw Messages.msg.noThreadCreated();
}
if (! runningThreads.add(thread)) {
throw Messages.msg.cannotAddThread();
}
if (currentSize >= largestPoolSize) {
largestPoolSize = currentSize + 1;
}
thread.start();
return;
}
workRunnable = this.workRunnable;
if (workRunnable != null) {
// someone else is waiting for a worker, so we wait for them
nextReady.await();
continue;
}
this.workRunnable = task;
try {
final long remaining = deadline - now;
if (remaining <= 0L) {
throw Messages.msg.executionTimedOut();
}
runnableDequeued.await(remaining, TimeUnit.MILLISECONDS);
now = System.currentTimeMillis();
if (this.workRunnable == null) {
// task was accepted
nextReady.signal();
return;
}
} finally {
this.workRunnable = null;
}
}
} finally {
lock.unlock();
}
}
public void executeNonBlocking(final Runnable task) throws RejectedExecutionException {
Assert.checkNotNullParam("task", task);
final Executor executor;
final Set runningThreads = this.runningThreads;
final Lock lock = this.lock;
lock.lock();
try {
for (;;) {
if (stop) {
throw Messages.msg.shutDownInitiated();
}
final Worker waitingWorker;
if ((waitingWorker = this.waitingWorker) != null) {
// a worker thread was waiting for a task; give it the task and wake it up
waitingWorker.setRunnable(task);
taskEnqueued.signal();
this.waitingWorker = null;
workerDequeued.signal();
return;
}
// no worker thread was waiting
final int currentSize = runningThreads.size();
if (currentSize < maxThreads) {
// if we haven't reached the thread limit yet, start up another thread
final Thread thread = threadFactory.newThread(new Worker(task));
if (thread == null) {
throw Messages.msg.noThreadCreated();
}
if (! runningThreads.add(thread)) {
throw Messages.msg.cannotAddThread();
}
if (currentSize >= largestPoolSize) {
largestPoolSize = currentSize + 1;
}
thread.start();
return;
}
// not blocking, not accepted
executor = handoffExecutor;
rejectedCount++;
// fall out to execute outside of lock
break;
}
} finally {
lock.unlock();
}
if (executor != null) {
executor.execute(task);
} else {
throw Messages.msg.executionRejected();
}
}
/** {@inheritDoc} */
public void addShutdownListener(final EventListener shutdownListener, final A attachment) {
shutdownListenable.addShutdownListener(shutdownListener, attachment);
}
private static long clipHigh(long value) {
return value < 0 ? Long.MAX_VALUE : value;
}
private final class Worker implements Runnable {
private Runnable runnable;
private Worker(final Runnable runnable) {
this.runnable = runnable;
}
private void setRunnable(final Runnable runnable) {
this.runnable = runnable;
}
private boolean awaitTimed(Condition condition, long idleSince) {
final long end = clipHigh(idleSince + keepAliveTime);
long remaining = end - System.currentTimeMillis();
if (remaining < 0L) {
return false;
}
if (stop) return false;
try {
condition.await(remaining, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
}
return ! stop;
}
public void run() {
final Lock lock = QueuelessExecutor.this.lock;
final Condition workerDequeued = QueuelessExecutor.this.workerDequeued;
final Condition runnableDequeued = QueuelessExecutor.this.runnableDequeued;
final Condition taskEnqueued = QueuelessExecutor.this.taskEnqueued;
final Set runningThreads = QueuelessExecutor.this.runningThreads;
final DirectExecutor taskExecutor = QueuelessExecutor.this.taskExecutor;
final Thread thread = Thread.currentThread();
long idleSince = Long.MAX_VALUE;
Runnable runnable = this.runnable;
boolean last = false;
this.runnable = null;
try {
MAIN: for (;;) {
// Run task
try {
taskExecutor.execute(runnable);
} catch (Throwable t) {
Messages.msg.executionFailed(t, runnable);
}
idleSince = System.currentTimeMillis();
// Get next task
lock.lock();
try {
if (stop || runningThreads.size() > maxThreads) {
if (runningThreads.remove(thread) && runningThreads.isEmpty()) {
threadDeath.signalAll();
last = true;
}
return;
}
if ((runnable = workRunnable) != null) {
// there's a task, take it and continue on to the top of the loop
workRunnable = null;
runnableDequeued.signal();
} else {
// no executors are waiting, so we wait instead for an executor
while (waitingWorker != null) {
// wait... to wait
if (! awaitTimed(workerDequeued, idleSince)) return;
if ((runnable = workRunnable) != null) {
// sniped an easy one by luck!
continue MAIN;
}
}
waitingWorker = this;
try {
do {
// wait for a job
if (! awaitTimed(taskEnqueued, idleSince)) return;
} while ((runnable = this.runnable) == null);
this.runnable = null;
} finally {
if (waitingWorker == this) {
waitingWorker = null;
workerDequeued.signal();
}
}
}
} finally {
lock.unlock();
}
}
} finally {
lock.lock();
try {
if (runningThreads.remove(thread) && stop && runningThreads.isEmpty()) {
threadDeath.signalAll();
last = true;
}
} finally {
lock.unlock();
}
if (last) {
shutdownListenable.shutdown();
}
}
}
}
}