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