/*
 * 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.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Thread factory which allows to specify a thread pool name and a thread name.
 *
 * The code is based on {@link java.util.concurrent.Executors.DefaultThreadFactory}.
 */
public class NamedThreadFactory implements ThreadFactory {
	private static final AtomicInteger poolNumber = new AtomicInteger(1);
	private final ThreadGroup group;
	private final AtomicInteger threadNumber = new AtomicInteger(1);
	private final String namePrefix;

	public NamedThreadFactory(final String poolName, final String threadName) {
		SecurityManager securityManager = System.getSecurityManager();
		group = (securityManager != null) ? securityManager.getThreadGroup() :
			Thread.currentThread().getThreadGroup();

		namePrefix = poolName +
			poolNumber.getAndIncrement() +
			threadName;
	}

	@Override
	public Thread newThread(Runnable runnable) {
		Thread t = new Thread(group, runnable,
			namePrefix + threadNumber.getAndIncrement(),
			0);
		if (t.isDaemon()) {
			t.setDaemon(false);
		}
		if (t.getPriority() != Thread.NORM_PRIORITY) {
			t.setPriority(Thread.NORM_PRIORITY);
		}
		return t;
	}
}