/**
*
* 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.hadoop.hbase.util;
import java.io.InterruptedIOException;
import java.io.PrintWriter;
import java.lang.Thread.UncaughtExceptionHandler;
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;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.util.ReflectionUtils;
/**
* Thread Utility
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class Threads {
protected static final Log LOG = LogFactory.getLog(Threads.class);
private static final AtomicInteger poolNumber = new AtomicInteger(1);
/**
* Utility method that sets name, daemon status and starts passed thread.
* @param t thread to run
* @return Returns the passed Thread <code>t</code>.
*/
public static Thread setDaemonThreadRunning(final Thread t) {
return setDaemonThreadRunning(t, t.getName());
}
/**
* Utility method that sets name, daemon status and starts passed thread.
* @param t thread to frob
* @param name new name
* @return Returns the passed Thread <code>t</code>.
*/
public static Thread setDaemonThreadRunning(final Thread t,
final String name) {
return setDaemonThreadRunning(t, name, null);
}
/**
* Utility method that sets name, daemon status and starts passed thread.
* @param t thread to frob
* @param name new name
* @param handler A handler to set on the thread. Pass null if want to
* use default handler.
* @return Returns the passed Thread <code>t</code>.
*/
public static Thread setDaemonThreadRunning(final Thread t,
final String name, final UncaughtExceptionHandler handler) {
t.setName(name);
if (handler != null) {
t.setUncaughtExceptionHandler(handler);
}
t.setDaemon(true);
t.start();
return t;
}
/**
* Shutdown passed thread using isAlive and join.
* @param t Thread to shutdown
*/
public static void shutdown(final Thread t) {
shutdown(t, 0);
}
/**
* Shutdown passed thread using isAlive and join.
* @param joinwait Pass 0 if we're to wait forever.
* @param t Thread to shutdown
*/
public static void shutdown(final Thread t, final long joinwait) {
if (t == null) return;
while (t.isAlive()) {
try {
t.join(joinwait);
} catch (InterruptedException e) {
LOG.warn(t.getName() + "; joinwait=" + joinwait, e);
}
}
}
/**
* @param t Waits on the passed thread to die dumping a threaddump every
* minute while its up.
* @throws InterruptedException
*/
public static void threadDumpingIsAlive(final Thread t)
throws InterruptedException {
if (t == null) {
return;
}
while (t.isAlive()) {
t.join(60 * 1000);
if (t.isAlive()) {
ReflectionUtils.printThreadInfo(new PrintWriter(System.out),
"Automatic Stack Trace every 60 seconds waiting on " +
t.getName());
}
}
}
/**
* If interrupted, just prints out the interrupt on STDOUT, resets interrupt and returns
* @param millis How long to sleep for in milliseconds.
*/
public static void sleep(long millis) {
try {
Thread.sleep(millis);
} catch (InterruptedException e) {
e.printStackTrace();
Thread.currentThread().interrupt();
}
}
/**
* Sleeps for the given amount of time even if interrupted. Preserves
* the interrupt status.
* @param msToWait the amount of time to sleep in milliseconds
*/
public static void sleepWithoutInterrupt(final long msToWait) {
long timeMillis = System.currentTimeMillis();
long endTime = timeMillis + msToWait;
boolean interrupted = false;
while (timeMillis < endTime) {
try {
Thread.sleep(endTime - timeMillis);
} catch (InterruptedException ex) {
interrupted = true;
}
timeMillis = System.currentTimeMillis();
}
if (interrupted) {
Thread.currentThread().interrupt();
}
}
/**
* Create a new CachedThreadPool with a bounded number as the maximum
* thread size in the pool.
*
* @param maxCachedThread the maximum thread could be created in the pool
* @param timeout the maximum time to wait
* @param unit the time unit of the timeout argument
* @param threadFactory the factory to use when creating new threads
* @return threadPoolExecutor the cachedThreadPool with a bounded number
* as the maximum thread size in the pool.
*/
public static ThreadPoolExecutor getBoundedCachedThreadPool(
int maxCachedThread, long timeout, TimeUnit unit,
ThreadFactory threadFactory) {
ThreadPoolExecutor boundedCachedThreadPool =
new ThreadPoolExecutor(maxCachedThread, maxCachedThread, timeout,
TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>(), threadFactory);
// allow the core pool threads timeout and terminate
boundedCachedThreadPool.allowCoreThreadTimeOut(true);
return boundedCachedThreadPool;
}
/**
* Returns a {@link java.util.concurrent.ThreadFactory} that names each created thread uniquely,
* with a common prefix.
* @param prefix The prefix of every created Thread's name
* @return a {@link java.util.concurrent.ThreadFactory} that names threads
*/
public static ThreadFactory getNamedThreadFactory(final String prefix) {
SecurityManager s = System.getSecurityManager();
final ThreadGroup threadGroup = (s != null) ? s.getThreadGroup() : Thread.currentThread()
.getThreadGroup();
return new ThreadFactory() {
final AtomicInteger threadNumber = new AtomicInteger(1);
private final int poolNumber = Threads.poolNumber.getAndIncrement();
final ThreadGroup group = threadGroup;
@Override
public Thread newThread(Runnable r) {
final String name = prefix + "-pool-" + poolNumber + "-thread-"
+ threadNumber.getAndIncrement();
return new Thread(group, r, name);
}
};
}
/**
* Same as {#newDaemonThreadFactory(String, UncaughtExceptionHandler)},
* without setting the exception handler.
*/
public static ThreadFactory newDaemonThreadFactory(final String prefix) {
return newDaemonThreadFactory(prefix, null);
}
/**
* Get a named {@link ThreadFactory} that just builds daemon threads.
* @param prefix name prefix for all threads created from the factory
* @param handler unhandles exception handler to set for all threads
* @return a thread factory that creates named, daemon threads with
* the supplied exception handler and normal priority
*/
public static ThreadFactory newDaemonThreadFactory(final String prefix,
final UncaughtExceptionHandler handler) {
final ThreadFactory namedFactory = getNamedThreadFactory(prefix);
return new ThreadFactory() {
@Override
public Thread newThread(Runnable r) {
Thread t = namedFactory.newThread(r);
if (handler != null) {
t.setUncaughtExceptionHandler(handler);
}
if (!t.isDaemon()) {
t.setDaemon(true);
}
if (t.getPriority() != Thread.NORM_PRIORITY) {
t.setPriority(Thread.NORM_PRIORITY);
}
return t;
}
};
}
}