org.apache.flink.runtime.util.ExecutorThreadFactory Maven / Gradle / Ivy
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* 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.flink.runtime.util;
import java.lang.Thread.UncaughtExceptionHandler;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicInteger;
import static org.apache.flink.util.Preconditions.checkNotNull;
/**
* A thread factory intended for use by critical thread pools. Critical thread pools here
* mean thread pools that support Flink's core coordination and processing work, and which
* must not simply cause unnoticed errors.
*
* The thread factory can be given an {@link UncaughtExceptionHandler} for the threads.
* If no handler is explicitly given, the default handler for uncaught exceptions will log
* the exceptions and kill the process afterwards. That guarantees that critical exceptions are
* not accidentally lost and leave the system running in an inconsistent state.
*
*
Threads created by this factory are all called '(pool-name)-thread-n', where
* (pool-name) is configurable, and n is an incrementing number.
*
*
All threads created by this factory are daemon threads and have the default (normal)
* priority.
*/
public class ExecutorThreadFactory implements ThreadFactory {
/** The thread pool name used when no explicit pool name has been specified */
private static final String DEFAULT_POOL_NAME = "flink-executor-pool";
private final AtomicInteger threadNumber = new AtomicInteger(1);
private final ThreadGroup group;
private final String namePrefix;
private final UncaughtExceptionHandler exceptionHandler;
// ------------------------------------------------------------------------
/**
* Creates a new thread factory using the default thread pool name ('flink-executor-pool')
* and the default uncaught exception handler (log exception and kill process).
*/
public ExecutorThreadFactory() {
this(DEFAULT_POOL_NAME);
}
/**
* Creates a new thread factory using the given thread pool name and the default
* uncaught exception handler (log exception and kill process).
*
* @param poolName The pool name, used as the threads' name prefix
*/
public ExecutorThreadFactory(String poolName) {
this(poolName, FatalExitExceptionHandler.INSTANCE);
}
/**
* Creates a new thread factory using the given thread pool name and the given
* uncaught exception handler.
*
* @param poolName The pool name, used as the threads' name prefix
* @param exceptionHandler The uncaught exception handler for the threads
*/
public ExecutorThreadFactory(String poolName, UncaughtExceptionHandler exceptionHandler) {
checkNotNull(poolName, "poolName");
SecurityManager securityManager = System.getSecurityManager();
this.group = (securityManager != null) ? securityManager.getThreadGroup() :
Thread.currentThread().getThreadGroup();
this.namePrefix = poolName + "-thread-";
this.exceptionHandler = exceptionHandler;
}
// ------------------------------------------------------------------------
@Override
public Thread newThread(Runnable runnable) {
Thread t = new Thread(group, runnable, namePrefix + threadNumber.getAndIncrement());
t.setDaemon(true);
// normalize the priority
if (t.getPriority() != Thread.NORM_PRIORITY) {
t.setPriority(Thread.NORM_PRIORITY);
}
// optional handler for uncaught exceptions
if (exceptionHandler != null) {
t.setUncaughtExceptionHandler(exceptionHandler);
}
return t;
}
// --------------------------------------------------------------------------------------------
}