1 /* 2 * Copyright (c) 2015, 2019, 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; 25 26 /* 27 * @test TestDisableExplicitGC 28 * @requires vm.opt.DisableExplicitGC == null 29 * @summary Verify GC behavior with DisableExplicitGC flag. 30 * @library /test/lib 31 * @modules java.base/jdk.internal.misc 32 * @modules jdk.management/com.sun.management.internal 33 * @run main/othervm -Xlog:gc=debug gc.TestDisableExplicitGC 34 * @run main/othervm/fail -XX:+DisableExplicitGC -Xlog:gc=debug gc.TestDisableExplicitGC 35 * @run main/othervm -XX:-DisableExplicitGC -Xlog:gc=debug gc.TestDisableExplicitGC 36 */ 37 import java.lang.management.GarbageCollectorMXBean; 38 import java.util.List; 39 import static jdk.test.lib.Asserts.*; 40 41 public class TestDisableExplicitGC { 42 main(String[] args)43 public static void main(String[] args) throws InterruptedException { 44 List<GarbageCollectorMXBean> list = java.lang.management.ManagementFactory.getGarbageCollectorMXBeans(); 45 long collectionCountBefore = getCollectionCount(list); 46 System.gc(); 47 long collectionCountAfter = getCollectionCount(list); 48 assertLT(collectionCountBefore, collectionCountAfter); 49 } 50 getCollectionCount(List<GarbageCollectorMXBean> list)51 private static long getCollectionCount(List<GarbageCollectorMXBean> list) { 52 int collectionCount = 0; 53 for (GarbageCollectorMXBean gcMXBean : list) { 54 collectionCount += gcMXBean.getCollectionCount(); 55 } 56 return collectionCount; 57 } 58 } 59