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 TestHumongousShrinkHeap 26 * @bug 8037925 27 * @summary Verify that heap shrinking after GC of hard defragmented by humongous object heap 28 * @library /testlibrary 29 * @author Andrey Zakharov /andrey.x.zakharov@oracle.com/ 30 * @author Dmitry Fazunenko /dmitry.fazunenko@oracle.com/ 31 * @run main/othervm -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=50 -XX:+UseG1GC -XX:G1HeapRegionSize=1M -Xloggc:gc_10_50.log TestHumongousShrinkHeap 32 */ 33 import com.oracle.java.testlibrary.MemoryUsagePrinter; 34 import com.oracle.java.testlibrary.TestShrinkHeap; 35 import java.util.ArrayList; 36 import java.util.List; 37 38 public class TestHumongousShrinkHeap extends TestShrinkHeap { 39 40 private static final ArrayList< ArrayList< byte[]>> garbage = new ArrayList<>(); 41 private static final int PageSize = 1024 * 1024; // 1M 42 private static final int PagesNum = 5; 43 private final int HumongousObjectSize; 44 45 public TestHumongousShrinkHeap() { 46 super(); 47 HumongousObjectSize = Math.round(.9f * PageSize); 48 System.out.println("Will allocate objects of size=" + MemoryUsagePrinter.humanReadableByteCount(HumongousObjectSize, true)); 49 } 50 51 public void eat() { 52 for (int i = 0; i < PagesNum; i++) { 53 ArrayList<byte[]> stuff = new ArrayList<>(); 54 eatList(stuff, 100, HumongousObjectSize); 55 MemoryUsagePrinter.printMemoryUsage("eat #" + i); 56 garbage.add(stuff); 57 } 58 } 59 60 public void free() { 61 //do not free last one list 62 garbage.subList(0, garbage.size() - 1).clear(); 63 64 // do not free last one element from last list 65 ArrayList stuff = garbage.get(garbage.size() - 1); 66 stuff.subList(0, stuff.size() - 1).clear(); 67 System.gc(); 68 } 69 70 public static void main(String[] args) { 71 new TestHumongousShrinkHeap().test(); 72 } 73 74 public static void eatList(List garbage, int count, int size) { 75 for (int i = 0; i < count; i++) { 76 garbage.add(new byte[size]); 77 } 78 } 79 }