ThreadRenamingRunnable.java

/*
 * (C) 2007-2012 Alibaba Group Holding Limited.
 * 
 * Licensed 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.
 */
/*
 * Copyright 2009 Red Hat, Inc.
 *
 * Red Hat 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 com.taobao.gecko.service.timer;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;


/**
 * A {@link Runnable} that changes the current thread name and reverts it back
 * when its execution ends. To change the default thread names set by Netty, use
 * {@link #setThreadNameDeterminer(ThreadNameDeterminer)}.
 * 
 * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
 * @author <a href="http://gleamynode.net/">Trustin Lee</a>
 * 
 * 
 * @apiviz.landmark
 * @apiviz.has org.jboss.netty.util.ThreadNameDeterminer oneway - -
 * 
 */
public class ThreadRenamingRunnable implements Runnable {

    private static final Log logger = LogFactory.getLog(ThreadRenamingRunnable.class);

    private final Runnable runnable;
    private final String proposedThreadName;


    /**
     * Creates a new instance which wraps the specified {@code runnable} and
     * changes the thread name to the specified thread name when the specified
     * {@code runnable} is running.
     */
    public ThreadRenamingRunnable(Runnable runnable, String proposedThreadName) {
        if (runnable == null) {
            throw new NullPointerException("runnable");
        }
        if (proposedThreadName == null) {
            throw new NullPointerException("proposedThreadName");
        }
        this.runnable = runnable;
        this.proposedThreadName = proposedThreadName;
    }


    public void run() {
        final Thread currentThread = Thread.currentThread();
        final String oldThreadName = currentThread.getName();
        final String newThreadName = this.proposedThreadName;

        // Change the thread name before starting the actual runnable.
        boolean renamed = false;
        if (!oldThreadName.equals(newThreadName)) {
            try {
                currentThread.setName(newThreadName);
                renamed = true;
            }
            catch (SecurityException e) {
                logger.debug("Failed to rename a thread " + "due to security restriction.", e);
            }
        }

        // Run the actual runnable and revert the name back when it ends.
        try {
            this.runnable.run();
        }
        finally {
            if (renamed) {
                // Revert the name back if the current thread was renamed.
                // We do not check the exception here because we know it works.
                currentThread.setName(oldThreadName);
            }
        }
    }

}