1 /*

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

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

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    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

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    23 

    24 /**

    25  * @test TestSoftReferencesBehaviorOnOOME

    26  * @key gc

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

    28  * @library /test/lib

    29  * @modules java.base/jdk.internal.misc

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

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

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

    33  */

    34 import jdk.test.lib.Utils;

    35 import jdk.test.lib.Asserts;

    36 import java.lang.ref.SoftReference;

    37 import java.util.LinkedList;

    38 import java.util.Random;

    39 

    40 public class TestSoftReferencesBehaviorOnOOME {

    41 

    42     /**

    43      * Test generates a lot of soft references to objects with random payloads.

    44      * Then it provokes OOME and checks that all SoftReferences has been gone

    45      * @param args - [minSize] [maxSize] [freq]

    46      *  where

    47      *  - minSize - min size of random objects

    48      *  - maxSize - max size of random objects

    49      */

    50     public static void main(String[] args) {

    51         long minSize = DEFAULT_MIN_SIZE;

    52         long maxSize = DEFAULT_MAX_SIZE;

    53 

    54         if ( args.length >= 2) {

    55             maxSize = getBytesCount(args[1]);

    56         }

    57 

    58         if ( args.length >= 1) {

    59             minSize = getBytesCount(args[0]);

    60         }

    61 

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

    63     }

    64 

    65     /**

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

    67      */

    68     void softReferencesOom(long minSize, long maxSize) {

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

    70 

    71         LinkedList<SoftReference> arrSoftRefs = new LinkedList();

    72         staticRef = arrSoftRefs;

    73         LinkedList arrObjects = new LinkedList();

    74         staticRef = arrObjects;

    75 

    76         long multiplier = maxSize - minSize;

    77         long numberOfNotNulledObjects = 0;

    78 

    79         try {

    80 

    81             // Lets allocate as many as we can - taking size of all SoftRerefences

    82             // by minimum. So it can provoke some GC but we surely will allocate enough.

    83             long numSofts = (long) ((0.95 * Runtime.getRuntime().totalMemory()) / minSize);

    84             System.out.println("num Soft: " + numSofts);

    85 

    86             while (numSofts-- > 0) {

    87                 int allocationSize = ((int) (RND_GENERATOR.nextDouble() * multiplier))

    88                             + (int)minSize;

    89                 arrSoftRefs.add(new SoftReference(new byte[allocationSize]));

    90             }

    91 

    92             System.out.println("free: " + Runtime.getRuntime().freeMemory());

    93 

    94             // provoke OOME.

    95             while (true) {

    96                 arrObjects.add(new byte[(int) Runtime.getRuntime().totalMemory()]);

    97             }

    98 

    99         } catch (OutOfMemoryError oome) {

   100 

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

   102             staticRef = null;

   103             arrObjects = null;

   104             long oomSoftArraySize = arrSoftRefs.size();

   105 

   106             for (SoftReference sr : arrSoftRefs) {

   107                 Object o = sr.get();

   108 

   109                 if (o != null) {

   110                     numberOfNotNulledObjects++;

   111                 }

   112             }

   113 

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

   115             arrSoftRefs = null;

   116             Asserts.assertFalse(numberOfNotNulledObjects > 0,

   117                     "" + numberOfNotNulledObjects + " out of "

   118                     + oomSoftArraySize + " SoftReferences was not "

   119                     + "null at time of OutOfMemoryError"

   120             );

   121         } finally {

   122             Asserts.assertTrue(arrObjects == null, "OOME hasn't been provoked");

   123             Asserts.assertTrue(arrSoftRefs == null, "OOME hasn't been provoked");

   124         }

   125     }

   126 

   127     private static final long getBytesCount(String arg) {

   128         String postfixes = "kMGT";

   129         long mod = 1;

   130 

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

   132             mod = postfixes.indexOf(arg.trim().charAt(arg.length() - 1));

   133 

   134             if (mod != -1) {

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

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

   137             } else {

   138                 mod = 1; // 10^0

   139             }

   140         }

   141 

   142         return Long.parseLong(arg) * mod;

   143     }

   144 

   145     private static final Random RND_GENERATOR = Utils.getRandomInstance();

   146     private static final long DEFAULT_MIN_SIZE = 512;

   147     private static final long DEFAULT_MAX_SIZE = 1024;

   148     private static Object staticRef; // to prevent compile optimisations

   149 }