java/org/apache/tomcat/util/threads/TaskThreadFactory.java

/*
 * 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.tomcat.util.threads;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicInteger;

import org.apache.tomcat.util.security.PrivilegedSetTccl;

/**
 * Simple task thread factory to use to create threads for an executor
 * implementation.
 */
public class TaskThreadFactory implements ThreadFactory {

    private final ThreadGroup group;
    private final AtomicInteger threadNumber = new AtomicInteger(1);
    private final String namePrefix;
    private final boolean daemon;
    private final int threadPriority;

    public TaskThreadFactory(String namePrefix, boolean daemon, int priority) {
        SecurityManager s = System.getSecurityManager();
        group = (s != null) ? s.getThreadGroup() : Thread.currentThread().getThreadGroup();
        this.namePrefix = namePrefix;
        this.daemon = daemon;
        this.threadPriority = priority;
    }

    @Override
    public Thread newThread(Runnable r) {
        ClassLoader loader = Thread.currentThread().getContextClassLoader();
        try {
            // Threads should not be created by the webapp classloader
            if (Constants.IS_SECURITY_ENABLED) {
                PrivilegedAction<Void> pa = new PrivilegedSetTccl(
                        getClass().getClassLoader());
                AccessController.doPrivileged(pa);
            } else {
                Thread.currentThread().setContextClassLoader(
                        getClass().getClassLoader());
            }
            TaskThread t = new TaskThread(group, r, namePrefix + threadNumber.getAndIncrement());
            t.setDaemon(daemon);
            t.setPriority(threadPriority);
            return t;
        } finally {
            if (Constants.IS_SECURITY_ENABLED) {
                PrivilegedAction<Void> pa = new PrivilegedSetTccl(loader);
                AccessController.doPrivileged(pa);
            } else {
                Thread.currentThread().setContextClassLoader(loader);
            }
        }
    }
}