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 * @key gc 27 * @bug 8037924 28 * @summary Verify that heap shrinking after full gc and dynamically changed free ratio 29 * @author Andrey Zakharov /andrey.x.zakharov@oracle.com/ 30 * @library /testlibrary 31 * @run main/othervm -XX:+UseAdaptiveSizePolicyWithSystemGC -XX:+UseParallelGC -XX:MinHeapFreeRatio=1 32 * -XX:MaxHeapFreeRatio=100 -Xloggc:gc.log TestDynShrinkHeap 33 */ 34 import java.lang.management.ManagementFactory; 35 import java.lang.management.MemoryUsage; 36 import java.util.ArrayList; 37 import com.oracle.java.testlibrary.TestDynamicVMOption; 38 import com.oracle.java.testlibrary.MemoryUsagePrinter; 39 import sun.management.ManagementFactoryHelper; 40 41 public class TestDynShrinkHeap { 42 43 public static final String MinFreeRatioFlagName = "MinHeapFreeRatio"; 44 public static final String MaxFreeRatioFlagName = "MaxHeapFreeRatio"; 45 46 public static ArrayList<byte[]> list = new ArrayList<byte[]>(0); 47 public static byte[] temp; 48 public static final int M = 1024 * 1024; // to make heap more manageable by test code 49 50 private final TestDynamicVMOption minRatioOption; 51 private final TestDynamicVMOption maxRatioOption; 52 53 public final class Labels { 54 public static final String beforeAllocation = "before allocation"; 55 public static final String arrayHalfed = "array halfed"; 56 public static final String underPressure = "under pressure"; 57 public static final String beforeGc = "before full GC"; 58 public static final String afterGc = "after full GC"; 59 60 } 61 62 63 public TestDynShrinkHeap() { 64 minRatioOption = new TestDynamicVMOption(MinFreeRatioFlagName); 65 maxRatioOption = new TestDynamicVMOption(MaxFreeRatioFlagName); 66 } 67 68 public void test() { 69 int minHeapFreeValue = minRatioOption.getIntValue(); 70 int maxHeapFreeValue = maxRatioOption.getIntValue(); 71 72 // with maxHeapFreeRatio = 100 heap will not shrink at all, so 73 if (maxHeapFreeValue == 100) { 74 maxHeapFreeValue = 95; 75 maxRatioOption.setIntValue(maxHeapFreeValue); 76 } 77 78 MemoryUsagePrinter.printMemoryUsage(Labels.beforeAllocation); 79 80 for (int i = 0; i < M; i++) { 81 list.add(new byte[1024]); 82 } 83 84 MemoryUsagePrinter.printMemoryUsage("allocated " + M + " arrays"); 85 86 list.subList(0, M / 2).clear(); 87 gc(); 88 MemoryUsagePrinter.printMemoryUsage(Labels.arrayHalfed); 89 MemoryUsage muFull = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage(); 90 91 maxRatioOption.setIntValue(minHeapFreeValue + 1); 92 gc(); 93 MemoryUsagePrinter.printMemoryUsage(Labels.underPressure); 94 MemoryUsage muPressure = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage(); 95 96 if (!(muPressure.getCommitted() < muFull.getCommitted())) { 97 throw new RuntimeException( 98 String.format("committed heap size under pressure is not less than committed full heap size, heap hasn't been shrunk?" 99 + "%n%s = %s%n%s = %s", 100 MinFreeRatioFlagName, 101 ManagementFactoryHelper.getDiagnosticMXBean().getVMOption(MinFreeRatioFlagName).getValue(), 102 MaxFreeRatioFlagName, 103 ManagementFactoryHelper.getDiagnosticMXBean().getVMOption(MaxFreeRatioFlagName).getValue() 104 ) 105 ); 106 } 107 } 108 109 public static void main(String[] args) { 110 new TestDynShrinkHeap().test(); 111 } 112 113 public static void gc() { 114 MemoryUsagePrinter.printMemoryUsage(Labels.beforeGc); 115 System.gc(); 116 MemoryUsagePrinter.printMemoryUsage(Labels.afterGc); 117 } 118 119 }