1 /*
   2  * Copyright (c) 2014, 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  * @test TestDynShrinkHeap
  26  * @bug 8016479
  27  * @summary Verify that heap shrinking after full gc and dynamically changed free ratio
  28  * @library /testlibrary
  29  * @run main/othervm -XX:+UseAdaptiveSizePolicyWithSystemGC -XX:+UseParallelGC -XX:MinHeapFreeRatio=0 -XX:MaxHeapFreeRatio=100 -Xloggc:gc.log TestDynShrinkHeap
  30  */
  31 
  32 import com.oracle.java.testlibrary.TestDynamicVMOption;
  33 import com.oracle.java.testlibrary.gc.MemoryUsagePrinter;
  34 import com.oracle.java.testlibrary.gc.TestShrinkHeap;
  35 import java.lang.management.ManagementFactory;
  36 import java.lang.management.MemoryUsage;
  37 import java.util.ArrayList;
  38 import sun.management.ManagementFactoryHelper;
  39 import static com.oracle.java.testlibrary.Asserts.*;
  40 
  41 public class TestDynShrinkHeap extends TestShrinkHeap {
  42 
  43     public static ArrayList<byte[]> list = new ArrayList<>(0);
  44     public static final int M = 1024 * 1024; // to make heap more manageable by test code
  45     
  46     private final TestDynamicVMOption maxRatioOption;   
  47     private final TestDynamicVMOption minRatioOption;   
  48 
  49     public TestDynShrinkHeap() {
  50         super();
  51         minRatioOption = new TestDynamicVMOption(MIN_FREE_RATIO_FLAG_NAME);
  52         maxRatioOption = new TestDynamicVMOption(MAX_FREE_RATIO_FLAG_NAME);
  53 
  54         // with maxHeapFreeRatio = 100 heap will not shrink at all, so
  55         if (maxRatioOption.getIntValue() == 100) {
  56             maxRatioOption.setIntValue(95);
  57         }
  58     }
  59     
  60     public final void test() {
  61         System.gc();
  62         MemoryUsagePrinter.printMemoryUsage("init");
  63 
  64         eat();        
  65         MemoryUsagePrinter.printMemoryUsage("eaten");
  66         MemoryUsage muFull = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
  67         
  68         free();
  69         MemoryUsagePrinter.printMemoryUsage("free");
  70         MemoryUsage muFree = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
  71 
  72         assertLessThan(muFree.getCommitted(), muFull.getCommitted(), String.format(
  73                 "committed free heap size is not less than committed full heap size, heap hasn't been shrunk?%n"
  74                 + "%s = %s%n%s = %s",
  75                 MIN_FREE_RATIO_FLAG_NAME,
  76                 ManagementFactoryHelper.getDiagnosticMXBean().getVMOption(MIN_FREE_RATIO_FLAG_NAME).getValue(),
  77                 MAX_FREE_RATIO_FLAG_NAME,
  78                 ManagementFactoryHelper.getDiagnosticMXBean().getVMOption(MAX_FREE_RATIO_FLAG_NAME).getValue()
  79         ));
  80     }
  81     
  82     protected void eat() {
  83         for (int i = 0; i < M; i++) {
  84             list.add(new byte[1024]);
  85         }
  86         MemoryUsagePrinter.printMemoryUsage("allocated " + M + " arrays");
  87         
  88         list.subList(0, M / 2).clear();
  89         System.gc();
  90         MemoryUsagePrinter.printMemoryUsage("array halfed");
  91     }
  92 
  93     protected void free() {  
  94         maxRatioOption.setIntValue(minRatioOption.getIntValue() + 1);
  95         System.gc();
  96         MemoryUsagePrinter.printMemoryUsage("under pressure");
  97     }
  98 
  99     public static void main(String[] args) {
 100         new TestDynShrinkHeap().test();
 101     }
 102 }