/*

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * 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.

 *

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 */

/*

 * @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<byte []>();

        boolean hasException = false;

        while (!hasException) {

            byte [] megaByte;

            try {

                megaByte = new byte [MB];

                data.add(megaByte);

            } catch (OutOfMemoryError e) {

                megaByte = null;    // Free memory ASAP

                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<SecretKey>() {

            @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();

        }

    }

}