// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
package jodd.util;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Thread utilities.
*/
public class ThreadUtil {
/**
* Puts a thread to sleep, without throwing an InterruptedException.
*
* @param ms the length of time to sleep in milliseconds
*/
public static void sleep(long ms) {
try {
Thread.sleep(ms);
} catch (InterruptedException iex) {
Thread.currentThread().interrupt();
}
}
/**
* Puts a thread to sleep forever.
*/
public static void sleep() {
try {
Thread.sleep(Long.MAX_VALUE);
} catch (InterruptedException iex) {
Thread.currentThread().interrupt();
}
}
// ---------------------------------------------------------------- synchronization
/**
* Waits for a object for synchronization purposes.
*/
public static void wait(Object obj) {
synchronized (obj) {
try {
obj.wait();
} catch (InterruptedException inex) {
Thread.currentThread().interrupt();
}
}
}
/**
* Waits for a object or a timeout for synchronization purposes.
*/
public static void wait(Object obj, long timeout) {
synchronized (obj) {
try {
obj.wait(timeout);
} catch (InterruptedException inex) {
Thread.currentThread().interrupt();
}
}
}
/**
* Notifies an object for synchronization purposes.
*/
public static void notify(Object obj){
synchronized (obj) {
obj.notify();
}
}
/**
* Notifies an object for synchronization purposes.
*/
public static void notifyAll(Object obj){
synchronized (obj) {
obj.notifyAll();
}
}
// ---------------------------------------------------------------- join
public static void join(Thread thread) {
try {
thread.join();
} catch (InterruptedException inex) {
Thread.currentThread().interrupt();
}
}
public static void join(Thread thread, long millis) {
try {
thread.join(millis);
} catch (InterruptedException inex) {
Thread.currentThread().interrupt();
}
}
public static void join(Thread thread, long millis, int nanos) {
try {
thread.join(millis, nanos);
} catch (InterruptedException inex) {
Thread.currentThread().interrupt();
}
}
// ---------------------------------------------------------------- pool
/**
* Creates new daemon thread factory.
*/
public static ThreadFactory daemonThreadFactory(String name) {
return daemonThreadFactory(name, Thread.NORM_PRIORITY);
}
/**
* Creates new daemon thread factory.
*/
public static ThreadFactory daemonThreadFactory(String name, int priority) {
return new ThreadFactory() {
private AtomicInteger count = new AtomicInteger();
@Override
public Thread newThread(Runnable r) {
Thread thread = new Thread(r);
thread.setName(name + '-' + count.incrementAndGet());
thread.setDaemon(true);
thread.setPriority(priority);
return thread;
}
};
}
/**
* Creates new core thread pool.
* @see #newCoreThreadPool(String, int, int, int)
*/
public static ExecutorService newCoreThreadPool(String name) {
final int cpus = Runtime.getRuntime().availableProcessors();
return newCoreThreadPool(name, 5 * cpus, 15 * cpus, 60);
}
/**
* Creates core thread pool. Uses direct hand-off (<code>SynchronousQueue</code>)
* and <code>CallerRunsPolicy</code> to avoid deadlocks since tasks may have
* internal dependencies.
* <p>
* <code>Executors.newCachedThreadPool()</code> isn't a great choice for server
* code that's servicing multiple clients and concurrent requests.
* 1) It's unbounded, and 2) The unbounded problem is exacerbated by the fact that
* the Executor is fronted by a SynchronousQueue which means there's a direct
* handoff between the task-giver and the thread pool. Each new task will create
* a new thread if all existing threads are busy. This is generally a bad strategy
* for server code. When the CPU gets saturated, existing tasks take longer to finish.
* Yet more tasks are being submitted and more threads created, so tasks take longer and
* longer to complete. When the CPU is saturated, more threads is definitely not what the server needs.
*/
public static ExecutorService newCoreThreadPool(String name, int coreSize, int maxSize, int idleTimeoutInSeconds) {
return newCoreThreadPool(daemonThreadFactory(name), coreSize, maxSize, idleTimeoutInSeconds);
}
public static ExecutorService newCoreThreadPool(ThreadFactory threadFactory, int coreSize, int maxSize, int idleTimeoutInSeconds) {
return new ThreadPoolExecutor(
coreSize,
maxSize,
idleTimeoutInSeconds, TimeUnit.SECONDS,
new SynchronousQueue<>(),
threadFactory,
new ThreadPoolExecutor.CallerRunsPolicy()
);
}
}