Java Component Examples

LockFreeQueue Example

/*
* Copyright (c) 2008 IBM Corporation
*
* 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 org.amino.examples;

import java.util.Queue;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import org.amino.ds.lockfree.LockFreeQueue;

public class QueueExample {

    private static final int ELEMENT_NUM = 1000;

    public static void main(String[] argvs) {

        ExecutorService exec = Executors.newFixedThreadPool(4);

        final Queue<String> queueStr = new LockFreeQueue<String>();

        Future[] results = new Future[ELEMENT_NUM];
        for (int i = 0; i < ELEMENT_NUM; ++i) {
            results[i] = exec.submit(new EnqueueTask(queueStr));
        }

        try {
            for (int i = 0; i < ELEMENT_NUM; ++i) {
                results[i].get();
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }

        exec.shutdown();
        try {
            exec.awaitTermination(60, TimeUnit.SECONDS);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println("Size of queue is " + queueStr.size());

        for (int i = 1; i <= ELEMENT_NUM; ++i) {
            if (!queueStr.contains(i)) {
                System.out.println("didn't find " + i);
            }
        }
    }

}

class EnqueueTask implements Runnable {
    private static AtomicInteger count = new AtomicInteger();
    Queue queue;

    public EnqueueTask(Queue q) {
        queue = q;
    }

    public void run() {
        if (!queue.offer(count.incrementAndGet())) {
            System.out.println("did not insert " + count.get());
        }
    }
}
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