1 /*
   2  * Copyright (c) 2002, 2020, Oracle and/or its affiliates. All rights reserved.
   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  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  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
  21  * questions.
  22  */
  23 
  24 
  25 /*
  26  * @test
  27  * @key stress gc randomness
  28  *
  29  * @summary converted from VM Testbase gc/memory/Churn/Churn1.
  30  * VM Testbase keywords: [gc, stress, stressopt, nonconcurrent]
  31  *
  32  * @library /vmTestbase
  33  *          /test/lib
  34  * @run driver jdk.test.lib.FileInstaller . .
  35  * @run main/othervm gc.memory.Churn.Churn1.Churn1
  36  */
  37 
  38 package gc.memory.Churn.Churn1;
  39 
  40 import nsk.share.test.*;
  41 import nsk.share.gc.*;
  42 
  43 /**
  44  *  Test that GC works with memory that is churn over.
  45  *
  46  *  This test starts a number of threads that create objects,
  47  *  keep references to them in array and overwrite them. The test
  48  *  test checks that GC is able to collect these objects.
  49  *
  50  *  This test will adjust the size of allocated objects to run
  51  *  environment.
  52  *
  53  *  @see nsk.share.gc.RunParams#getTestMemory()
  54  */
  55 public class Churn1 extends ThreadedGCTest {
  56         private int multiplier = 10;
  57         private int sizeOfArray;
  58 
  59         class ThreadObject implements Runnable {
  60                 private AllMemoryObject objectArray[] = new AllMemoryObject[sizeOfArray];
  61 
  62                 public ThreadObject() {
  63                         for (int i = 0; i < sizeOfArray; i ++)
  64                                 objectArray[i] = new AllMemoryObject(multiplier * i);
  65                 }
  66 
  67                 public void run() {
  68                         int index = LocalRandom.nextInt(sizeOfArray);
  69                         objectArray[index] = new AllMemoryObject(multiplier * index);
  70                 }
  71         }
  72 
  73         protected Runnable createRunnable(int i) {
  74                 return new ThreadObject();
  75         }
  76         public void run() {
  77                 sizeOfArray = (int) Math.min(Math.sqrt(runParams.getTestMemory() * 2 / runParams.getNumberOfThreads() / multiplier), Integer.MAX_VALUE);
  78                 super.run();
  79         }
  80 
  81         public static void main(String args[]) {
  82                 GC.runTest(new Churn1(), args);
  83         }
  84 }