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 HotspotRuntimeMBean.getSafepointSyncTime() 28 * @author Steve Bohne 29 * @modules java.management/sun.management 30 * @run main/othervm -XX:+UsePerfData GetSafepointSyncTime 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 GetSafepointSyncTime { 40 41 private static HotspotRuntimeMBean mbean = 42 (HotspotRuntimeMBean)ManagementFactoryHelper.getHotspotRuntimeMBean(); 43 44 private static final long NUM_THREAD_DUMPS = 300; 45 46 // Careful with these values. 47 private static final long MIN_VALUE_FOR_PASS = 1; 48 private static final long MAX_VALUE_FOR_PASS = Long.MAX_VALUE; 49 50 public static void main(String args[]) throws Exception { 51 long count = mbean.getSafepointCount(); 52 long value = mbean.getSafepointSyncTime(); 53 54 // Thread.getAllStackTraces() should cause safepoints. 55 // If this test is failing because it doesn't, 56 // MIN_VALUE_FOR_PASS should be reset to 0 57 for (int i = 0; i < NUM_THREAD_DUMPS; i++) { 58 Thread.getAllStackTraces(); 59 } 60 61 long count1 = mbean.getSafepointCount(); 62 long value1 = mbean.getSafepointSyncTime(); 63 64 System.out.format("Safepoint count=%d (diff=%d), sync time=%d ms (diff=%d)%n", 65 count1, count1-count, value1, value1-value); 66 67 if (value1 < MIN_VALUE_FOR_PASS || value1 > MAX_VALUE_FOR_PASS) { 68 throw new RuntimeException("Safepoint sync time " + 69 "illegal value: " + value1 + " ms " + 70 "(MIN = " + MIN_VALUE_FOR_PASS + "; " + 71 "MAX = " + MAX_VALUE_FOR_PASS + ")"); 72 } 73 74 for (int i = 0; i < NUM_THREAD_DUMPS; i++) { 75 Thread.getAllStackTraces(); 76 } 77 78 long count2 = mbean.getSafepointCount(); 79 long value2 = mbean.getSafepointSyncTime(); 80 81 System.out.format("Safepoint count=%d (diff=%d), sync time=%d ms (diff=%d)%n", 82 count2, count2-count1, value2, value2-value1); 83 84 if (value2 <= value1) { 85 throw new RuntimeException("Safepoint sync time " + 86 "did not increase " + 87 "(value1 = " + value1 + "; " + 88 "value2 = " + value2 + ")"); 89 } 90 91 System.out.println("Test passed."); 92 } 93 }