org.cesken.talks.memory.Worker.java Source code

Introduction

Here is the source code for org.cesken.talks.memory.Worker.java

Source

/*********************************************************************************
 * Copyright 2014-present Christian Esken
 * 
 * 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.cesken.talks.memory;

import java.lang.management.ManagementFactory;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.Callable;

import org.apache.commons.lang3.StringUtils;

/**
 * 
 * @author cesken
 *
 */
public class Worker implements Callable<String> {
    static int workCounter = 0;
    static int errorCount = 0;
    static final int ROUNDS = 10_000;

    String name = StringUtils.repeat("Worker".concat(Integer.toString(workCounter)), 10000);

    enum HousePart {
        Door, Window, Roof, Floor, Plumbing;

        Set<Callable<String>> workers = new HashSet<>();

        void register(Callable<String> w) {
            workers.add(w);
        }

        void unregister(Callable<String> w) {
            workers.remove(w);
        }
    }

    void work(HousePart housePart) throws Exception {
        housePart.register(this);
        call(); // do the work
        housePart.unregister(this);
    }

    public static void main(String[] args) {
        System.out.println("Working ... on creating a memory leak");
        System.out.println("JVM ID: " + ManagementFactory.getRuntimeMXBean().getName());
        for (int i = 0; i < ROUNDS; i++) {
            try {
                Worker worker = new Worker();
                worker.work(HousePart.Door);
            } catch (Exception exc) {
                errorCount++;
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                } // ignore
            }
        }
        System.out.println("Work done. errorCount=" + errorCount);
    }

    @Override
    public String call() throws Exception {
        if ((workCounter++ % 10) == 0) {
            throw new RuntimeException("Feeling ill");
        }

        return "Work done";
    }
}