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Java example source code file (TestProviderLeak.java)

This example Java source code file (TestProviderLeak.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

callable, crypto, deque, exception, executorservice, future, iteration, outofmemoryerror, pbekeyspec, pbkdf2withhmacsha1, reservation, sunjce, threading, threads, time_out, util

The TestProviderLeak.java Java example source code

/*
 * Copyright (c) 2005, 2013, 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.
 */

/*
 * @test
 * @bug 6578538 8027624
 * @summary com.sun.crypto.provider.SunJCE instance leak using KRB5 and
 *     LoginContext
 * @author Brad Wetmore
 *
 * @run main/othervm -Xmx20m TestProviderLeak
 *
 */

/*
 * We force the leak to become a problem by eating up most JVM free memory.
 * In current runs on a server and client machine, it took roughly 50-150
 * iterations to have the memory leak or time-out shut down other operations.
 * It complained about "JCE cannot authenticate the provider SunJCE" or timed
 * out.
 */

import javax.crypto.*;
import javax.crypto.spec.*;

import java.util.*;
import java.util.concurrent.*;

public class TestProviderLeak {
    private static final int MB = 1024 * 1024;
    // Currently, 3MB heap size is reserved for running testing iterations.
    // It is tweaked to make sure the test quickly triggers the memory leak
    // or throws out TimeoutException.
    private static final int RESERVATION = 3;
    // The maximum time, 5 seconds, to wait for each iteration.
    private static final int TIME_OUT = 5;

    private static Deque<byte []> eatupMemory() throws Exception {
        dumpMemoryStats("Before memory allocation");

        Deque<byte []> data = new ArrayDeque();
        boolean hasException = false;
        while (!hasException) {
            byte [] megaByte;
            try {
                megaByte = new byte [MB];
                data.add(megaByte);
            } catch (OutOfMemoryError e) {
                System.out.println("OOME is thrown when allocating "
                        + data.size() + "MB memory.");
                megaByte = null;

                for (int j = 0; j < RESERVATION && !data.isEmpty(); j++) {
                    data.removeLast();
                }
                System.gc();
                hasException = true;
            }
        }
        dumpMemoryStats("After memory allocation");

        return data;
    }

    private static void dumpMemoryStats(String s) throws Exception {
        Runtime rt = Runtime.getRuntime();
        System.out.println(s + ":\t"
            + rt.freeMemory() + " bytes free");
    }

    public static void main(String [] args) throws Exception {
        // Prepare the test
        final SecretKeyFactory skf =
            SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1", "SunJCE");
        final PBEKeySpec pbeKS = new PBEKeySpec(
            "passPhrase".toCharArray(), new byte [] { 0 }, 5, 512);

        ExecutorService executor = Executors.newSingleThreadExecutor();
        Callable<SecretKey> task = new Callable() {
            @Override
            public SecretKey call() throws Exception {
                return skf.generateSecret(pbeKS);
            }
        };

        // Eat up memory
        Deque<byte []> dummyData = eatupMemory();
        assert (dummyData != null);

        // Start testing iteration
        try {
            for (int i = 0; i <= 1000; i++) {
                if ((i % 20) == 0) {
                    // Calling gc() isn't dependable, but doesn't hurt.
                    // Gives better output in leak cases.
                    System.gc();
                    dumpMemoryStats("Iteration " + i);
                }

                Future<SecretKey> future = executor.submit(task);

                try {
                    future.get(TIME_OUT, TimeUnit.SECONDS);
                } catch (Exception e) {
                    dumpMemoryStats("\nException seen at iteration " + i);
                    throw e;
                }
            }
        } finally {
            // JTReg will time out after two minutes. Proactively release
            // the memory to avoid JTReg time-out situation.
            dummyData = null;
            System.gc();
            dumpMemoryStats("Memory dereference");
            executor.shutdownNow();
        }
    }
}

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