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 * Copyright (c) 2014 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

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 */

/**

 * @test TestSoftReferencesBehaviorOnOOME

 * @key gc

 * @summary Tests that all SoftReferences has been cleared at time of OOM.

 * @library /testlibrary

 * @build TestSoftReference

 * @run main/othervm -Xmx128m TestSoftReferencesBehaviorOnOOME 512 2k

 * @run main/othervm -Xmx128m TestSoftReferencesBehaviorOnOOME 128k 256k

 * @run main/othervm -Xmx128m TestSoftReferencesBehaviorOnOOME 2k 32k 10

 */

import com.oracle.java.testlibrary.Utils;

import java.lang.ref.SoftReference;

import java.util.LinkedList;

import java.util.Random;

public class TestSoftReferencesBehaviorOnOOME {

    private static final Random rndGenerator = Utils.getRandomInstance();

    public static void main(String[] args) {

        int semiRefAllocFrequency = DEFAULT_FREQUENCY;

        long minSize = DEFAULT_MIN_SIZE,

                maxSize = DEFAULT_MAX_SIZE;

        if ( args.length >= 3 ) {

            semiRefAllocFrequency = Integer.parseInt(args[2]);

        }

        if ( args.length >= 2) {

            maxSize = getBytesCount(args[1]);

        }

        if ( args.length >= 1) {

            minSize = getBytesCount(args[0]);

        }

        new TestSoftReferencesBehaviorOnOOME().softReferencesOom(minSize, maxSize, semiRefAllocFrequency);

    }

    /**

     * Test that all SoftReferences has been cleared at time of OOM.

     */

    void softReferencesOom(long minSize, long maxSize, int semiRefAllocFrequency) {

        System.out.format( "minSize = %d, maxSize = %d, freq = %d%n", minSize, maxSize, semiRefAllocFrequency );

        long counter = 0;

        long multiplier = maxSize - minSize;

        LinkedList<SoftReference> arrSoftRefs = new LinkedList();

        LinkedList arrObjects = new LinkedList();

        long numberOfNotNulledObjects = 0;

        long oomSoftArraySize = 0;

        try {

            while (true) {

                // Keep every Xth object to make sure we hit OOM pretty fast

                if (counter % semiRefAllocFrequency != 0) {

                    long allocationSize = ((int) (rndGenerator.nextDouble() * multiplier))

                            + minSize;

                    arrObjects.add(new byte[(int)allocationSize]);

                } else {

                    arrSoftRefs.add(new SoftReference(new Object()));

                }

                counter++;

                if (counter == Long.MAX_VALUE) {

                    counter = 0;

                }

            }

        } catch (OutOfMemoryError oome) {

            // Clear allocated ballast, so we don't get another OOM.

            arrObjects = null;

            // Get the number of soft refs first, so we don't trigger

            // another OOM.

            oomSoftArraySize = arrSoftRefs.size();

            for (SoftReference sr : arrSoftRefs) {

                Object o = sr.get();

                if (o != null) {

                    numberOfNotNulledObjects++;

                }

            }

            // Make sure we clear all refs before we return failure

            arrSoftRefs = null;

            if (numberOfNotNulledObjects > 0) {

                throw new RuntimeException(numberOfNotNulledObjects + " out of "

                        + oomSoftArraySize + " SoftReferences was not "

                        + "null at time of OutOfMemoryError");

            }

        } finally {

            arrSoftRefs = null;

            arrObjects = null;

        }

    }

    private static final long getBytesCount(String arg) {

        String postfixes = "kMGT";

        long mod = 1;

        if (arg.trim().length() >= 2) {

            mod = postfixes.indexOf(

                    arg.trim().charAt(arg.length() - 1)

            );

            if (mod != -1) {

                mod = (long) Math.pow(1024, mod+1);

                arg = arg.substring(0, arg.length() - 1);

            } else {

                mod = 1; // 10^0

            }

        }

        return Long.parseLong(arg) * mod;

    }

    private static final long DEFAULT_MIN_SIZE = 512;

    private static final long DEFAULT_MAX_SIZE = 1024;

    private static final int DEFAULT_FREQUENCY = 4;

}