1 /* 2 * Copyright (c) 2019, 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 package gc.z; 25 26 /* 27 * @test TestUncommit 28 * @requires vm.gc.Z 29 * @summary Test ZGC uncommit unused memory 30 * @run main/othervm -XX:+UseZGC -Xlog:gc*,gc+heap=debug,gc+stats=off -Xms128M -Xmx512M -XX:ZUncommitDelay=10 gc.z.TestUncommit true 2 31 */ 32 33 /* 34 * @test TestUncommit 35 * @requires vm.gc.Z 36 * @summary Test ZGC uncommit unused memory 37 * @run main/othervm -XX:+UseZGC -Xlog:gc*,gc+heap=debug,gc+stats=off -Xms512M -Xmx512M -XX:ZUncommitDelay=10 gc.z.TestUncommit false 1 38 */ 39 40 /* 41 * @test TestUncommit 42 * @requires vm.gc.Z 43 * @summary Test ZGC uncommit unused memory 44 * @run main/othervm -XX:+UseZGC -Xlog:gc*,gc+heap=debug,gc+stats=off -Xms128M -Xmx512M -XX:ZUncommitDelay=10 -XX:-ZUncommit gc.z.TestUncommit false 1 45 */ 46 47 import java.util.ArrayList; 48 49 public class TestUncommit { 50 private static final int delay = 10; // seconds 51 private static final int allocSize = 200 * 1024 * 1024; // 200M 52 private static final int smallObjectSize = 4 * 1024; // 4K 53 private static final int mediumObjectSize = 2 * 1024 * 1024; // 2M 54 private static final int largeObjectSize = allocSize; 55 56 private static volatile ArrayList<byte[]> keepAlive; 57 58 private static long capacity() { 59 return Runtime.getRuntime().totalMemory(); 60 } 61 62 private static void allocate(int objectSize) { 63 keepAlive = new ArrayList<>(); 64 for (int i = 0; i < allocSize; i+= objectSize) { 65 keepAlive.add(new byte[objectSize]); 66 } 67 } 68 69 private static void reclaim() { 70 keepAlive = null; 71 System.gc(); 72 } 73 74 private static void test(boolean enabled, int objectSize) throws Exception { 75 final var beforeAlloc = capacity(); 76 77 // Allocate memory 78 allocate(objectSize); 79 80 final var afterAlloc = capacity(); 81 82 // Reclaim memory 83 reclaim(); 84 85 // Wait shorter than the uncommit delay 86 Thread.sleep(delay * 1000 / 2); 87 88 final var beforeUncommit = capacity(); 89 90 // Wait longer than the uncommit delay 91 Thread.sleep(delay * 1000); 92 93 final var afterUncommit = capacity(); 94 95 System.out.println(" Uncommit Enabled: " + enabled); 96 System.out.println(" Uncommit Delay: " + delay); 97 System.out.println(" Object Size: " + objectSize); 98 System.out.println(" Alloc Size: " + allocSize); 99 System.out.println(" Before Alloc: " + beforeAlloc); 100 System.out.println(" After Alloc: " + afterAlloc); 101 System.out.println(" Before Uncommit: " + beforeUncommit); 102 System.out.println(" After Uncommit: " + afterUncommit); 103 System.out.println(); 104 105 // Verify 106 if (enabled) { 107 if (beforeUncommit == beforeAlloc) { 108 throw new Exception("Uncommitted too fast"); 109 } 110 111 if (afterUncommit >= afterAlloc) { 112 throw new Exception("Uncommitted too slow"); 113 } 114 115 if (afterUncommit < beforeAlloc) { 116 throw new Exception("Uncommitted too much"); 117 } 118 119 if (afterUncommit > beforeAlloc) { 120 throw new Exception("Uncommitted too little"); 121 } 122 } else { 123 if (afterAlloc > beforeUncommit || 124 afterAlloc > afterUncommit) { 125 throw new Exception("Should not uncommit"); 126 } 127 } 128 } 129 130 public static void main(String[] args) throws Exception { 131 final boolean enabled = Boolean.parseBoolean(args[0]); 132 final int iterations = Integer.parseInt(args[1]); 133 134 for (int i = 0; i < iterations; i++) { 135 System.out.println("Iteration " + i); 136 test(enabled, smallObjectSize); 137 test(enabled, mediumObjectSize); 138 test(enabled, largeObjectSize); 139 } 140 } 141 }