com.fusesource.forge.jmstest.threading.SteppablePool.java Source code

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Here is the source code for com.fusesource.forge.jmstest.threading.SteppablePool.java

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/*
 * Copyright (C) 2009, Progress Software Corporation and/or its
 * subsidiaries or affiliates.  All rights reserved.
 *
 * 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.
 */
package com.fusesource.forge.jmstest.threading;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

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

public class SteppablePool {

    private ExecutorService executor = null;
    private Map<String, Steppable> tasks = new HashMap<String, Steppable>();
    private Runnable controller = null;
    private long idleTimeout = 5000;
    private int minPoolSize = 10;
    private int maxPoolSize = 20;
    private long lastUnidle = System.currentTimeMillis();
    private long lastCount = Long.MIN_VALUE;
    private List<CountDownLatch> latches = new ArrayList<CountDownLatch>();

    private Log log = null;

    public SteppablePool(long idleTimeout, int minPoolSize, int maxPoolSize) {
        this.idleTimeout = idleTimeout;
        this.minPoolSize = minPoolSize;
        this.maxPoolSize = maxPoolSize;

        controller = new Runnable() {
            public void run() {
                log().info("Steppable pool is started.");
                while (true) {
                    if (isIdle()) {
                        if (System.currentTimeMillis() - lastUnidle > getIdleTimeout()) {
                            break;
                        }
                    } else {
                        log.debug("Steppable pool is still busy.");
                    }
                    try {
                        Thread.sleep(getIdleTimeout());
                    } catch (InterruptedException ie) {
                        break;
                    }
                }
                log().info("Steppable pool is finished.");
                for (CountDownLatch latch : latches) {
                    latch.countDown();
                }
                executor.shutdown();
            }
        };
        new Thread(controller).start();
    }

    synchronized public void touch() {
        lastUnidle = System.currentTimeMillis();
    }

    public void waitUntilFinished() {
        CountDownLatch latch = new CountDownLatch(1);
        latches.add(latch);
        try {
            latch.await();
        } catch (InterruptedException ie) {
        }
    }

    public ExecutorService getExecutor() {
        if (executor == null) {
            executor = new ThreadPoolExecutor(minPoolSize, maxPoolSize, getIdleTimeout(), TimeUnit.MILLISECONDS,
                    new LinkedBlockingQueue<Runnable>());
        }
        return executor;
    }

    public void remove(final Steppable s) {
        synchronized (tasks) {
            if (s.getState() == SteppableState.RELEASED) {
                tasks.remove(s.getName());
            }
        }
    }

    public void submit(final Steppable s) {
        synchronized (tasks) {
            tasks.put(s.getName(), s);
        }
        s.setPool(this);
        getExecutor().submit(new Runnable() {
            public void run() {
                s.initialize();
            }
        });
    }

    private boolean isIdle() {
        synchronized (tasks) {
            if (tasks.size() > 0) {
                lastUnidle = System.currentTimeMillis();
            }
            log().info("Pool still has " + (tasks.size()) + " tasks.");
            if (tasks.size() == lastCount) {
                for (Steppable s : tasks.values()) {
                    log.info("Task : " + s.getName() + ":" + s.getState());
                }
            } else {
                lastCount = tasks.size();
            }
            return (tasks.size() <= 0);
        }
    }

    private long getIdleTimeout() {
        return idleTimeout;
    }

    private Log log() {
        if (log == null) {
            log = LogFactory.getLog(this.getClass());
        }
        return log;
    }
}