log4j-core/src/test/java/org/apache/logging/log4j/test/appender/DeadlockAppender.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.logging.log4j.test.appender;

import java.util.concurrent.TimeUnit;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.LoggingException;
import org.apache.logging.log4j.core.Appender;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.appender.AbstractAppender;
import org.apache.logging.log4j.plugins.Plugin;
import org.apache.logging.log4j.plugins.PluginAttribute;
import org.apache.logging.log4j.plugins.PluginFactory;
import org.apache.logging.log4j.plugins.validation.constraints.Required;

/**
 *
 */
@Plugin(name="Deadlock", category ="Core", elementType=Appender.ELEMENT_TYPE, printObject=true)
public class DeadlockAppender extends AbstractAppender {

    private WorkerThread thread = null;

    private DeadlockAppender(final String name) {
        super(name, null, null, false, null);
        thread = new WorkerThread();
    }

    @Override
    public void start() {
        super.start();

    }

    @Override
    public boolean stop(final long timeout, final TimeUnit timeUnit) {
        setStopping();
        super.stop(timeout, timeUnit, false);
        thread.start();
        try {
            thread.join();
        } catch (final Exception ex) {
            System.out.println("Thread interrupted");
        }
        setStopped();
        return true;
    }

    @Override
    public void append(final LogEvent event) {
        throw new LoggingException("Always fail");
    }

    @PluginFactory
    public static DeadlockAppender createAppender(
        @PluginAttribute @Required(message = "A name for the Appender must be specified") final String name) {
        return new DeadlockAppender(name);
    }

    private class WorkerThread extends Thread {

        @Override
        public void run() {
            final Logger logger = LogManager.getLogger("org.apache.logging.log4j.test.WorkerThread");
            logger.debug("Worker is running");
        }
    }
}