1 /* 2 * Copyright (c) 2003, 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 26 * @bug 4858522 27 * @summary Basic unit test of HotspotClassLoadingMBean.getSafepointCount() 28 * @author Steve Bohne 29 * 30 * @run main/othervm -XX:+UsePerfData GetSafepointCount 31 */ 32 33 /* 34 * This test is just a sanity check and does not check for the correct value. 35 */ 36 37 import sun.management.*; 38 39 public class GetSafepointCount { 40 41 private static HotspotRuntimeMBean mbean = 42 (HotspotRuntimeMBean)ManagementFactoryHelper.getHotspotRuntimeMBean(); 43 44 private static final long NUM_THREAD_DUMPS = 5; 45 46 // Careful with these values. 47 private static final long MIN_VALUE_FOR_PASS = NUM_THREAD_DUMPS; 48 private static final long MAX_VALUE_FOR_PASS = Long.MAX_VALUE; 49 50 private static boolean trace = false; 51 52 public static void main(String args[]) throws Exception { 53 if (args.length > 0 && args[0].equals("trace")) { 54 trace = true; 55 } 56 57 // Thread.getAllStackTraces() should cause safepoints. 58 // If this test is failing because it doesn't, 59 // MIN_VALUE_FOR_PASS should be reset to 0 60 for (int i = 0; i < NUM_THREAD_DUMPS; i++) { 61 Thread.getAllStackTraces(); 62 } 63 64 long value = mbean.getSafepointCount(); 65 66 if (trace) { 67 System.out.println("Safepoint count: " + value); 68 } 69 70 if (value < MIN_VALUE_FOR_PASS || value > MAX_VALUE_FOR_PASS) { 71 throw new RuntimeException("Safepoint count " + 72 "illegal value: " + value + " " + 73 "(MIN = " + MIN_VALUE_FOR_PASS + "; " + 74 "MAX = " + MAX_VALUE_FOR_PASS + ")"); 75 } 76 77 for (int i = 0; i < NUM_THREAD_DUMPS; i++) { 78 Thread.getAllStackTraces(); 79 } 80 81 long value2 = mbean.getSafepointCount(); 82 83 if (trace) { 84 System.out.println("Safepoint count2: " + value2); 85 } 86 87 if (value2 <= value) { 88 throw new RuntimeException("Safepoint count " + 89 "did not increase " + 90 "(value = " + value + "; " + 91 "value2 = " + value2 + ")"); 92 } 93 94 System.out.println("Test passed."); 95 } 96 }