Java example source code file (AnonLoggerWeakRefLeak.java)

This example Java source code file (AnonLoggerWeakRefLeak.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

anonloggerweakrefleak, default_loop_time, error, exception, interruptedexception, log, logging, numberformatexception, runtimeexception, simpleapplication

The AnonLoggerWeakRefLeak.java Java example source code

/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

import java.util.logging.*;

public class AnonLoggerWeakRefLeak extends SimpleApplication {
    // The test driver script will allow this program to run until we
    // reach DEFAULT_LOOP_TIME or a decrease in instance counts is
    // observed. For this particular WeakReference leak, the count
    // was always observed to be increasing so if we get a decreasing
    // count, then the leak is fixed in the bits being tested.
    // Two minutes has been enough time to observe a decrease in
    // fixed bits on overloaded systems, but the test will likely
    // finish more quickly.
    public static int DEFAULT_LOOP_TIME = 120;  // time is in seconds

    // execute the AnonLoggerWeakRefLeak app work
    public void doMyAppWork(String[] args) throws Exception {
        int loop_time = 0;
        int max_loop_time = DEFAULT_LOOP_TIME;

        // args[0] is the port-file
        if (args.length < 2) {
            System.out.println("INFO: using default time of "
                + max_loop_time + " seconds.");
        } else {
            try {
                max_loop_time = Integer.parseInt(args[1]);
            } catch (NumberFormatException nfe) {
                throw new RuntimeException("Error: '" + args[1]
                    + "': is not a valid seconds value.");
            }
        }

        long count = 0;
        long now = 0;
        long startTime = System.currentTimeMillis();

        while (now < (startTime + (max_loop_time * 1000))) {
            if ((count % 1000) == 0) {
                // Print initial call count to let caller know that
                // we're up and running and then periodically
                System.out.println("INFO: call count = " + count);
            }

            for (int i = 0; i < 100; i++) {
                // this Logger call is leaking a WeakReference in Logger.kids
                java.util.logging.Logger.getAnonymousLogger();
                count++;
            }

            try {
                // delay for 1/10 of a second to avoid CPU saturation
                Thread.sleep(100);
            } catch (InterruptedException ie) {
                // ignore any exceptions
            }

            now = System.currentTimeMillis();
        }

        System.out.println("INFO: final loop count = " + count);
    }

    public static void main(String[] args) throws Exception {
        AnonLoggerWeakRefLeak myApp = new AnonLoggerWeakRefLeak();

        SimpleApplication.setMyApp(myApp);

        SimpleApplication.main(args);
    }
}