1 /* 2 * Copyright (c) 2003, 2013, 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 * @run main/othervm -XX:+UsePerfData GetSafepointSyncTime 30 */ 31 32 /* 33 * This test is just a sanity check and does not check for the correct value. 34 */ 35 36 import sun.management.*; 37 38 public class GetSafepointSyncTime { 39 40 private static HotspotRuntimeMBean mbean = 41 (HotspotRuntimeMBean)ManagementFactoryHelper.getHotspotRuntimeMBean(); 42 43 private static final long NUM_THREAD_DUMPS = 300; 44 45 // Careful with these values. 46 private static final long MIN_VALUE_FOR_PASS = 1; 47 private static final long MAX_VALUE_FOR_PASS = Long.MAX_VALUE; 48 49 public static void main(String args[]) throws Exception { 50 long count = mbean.getSafepointCount(); 51 long value = mbean.getSafepointSyncTime(); 52 53 // Thread.getAllStackTraces() should cause safepoints. 54 // If this test is failing because it doesn't, 55 // MIN_VALUE_FOR_PASS should be reset to 0 56 for (int i = 0; i < NUM_THREAD_DUMPS; i++) { 57 Thread.getAllStackTraces(); 58 } 59 60 long count1 = mbean.getSafepointCount(); 61 long value1 = mbean.getSafepointSyncTime(); 62 63 System.out.format("Safepoint count=%d (diff=%d), sync time=%d ms (diff=%d)%n", 64 count1, count1-count, value1, value1-value); 65 66 if (value1 < MIN_VALUE_FOR_PASS || value1 > MAX_VALUE_FOR_PASS) { 67 throw new RuntimeException("Safepoint sync time " + 68 "illegal value: " + value1 + " ms " + 69 "(MIN = " + MIN_VALUE_FOR_PASS + "; " + 70 "MAX = " + MAX_VALUE_FOR_PASS + ")"); 71 } 72 73 for (int i = 0; i < NUM_THREAD_DUMPS; i++) { 74 Thread.getAllStackTraces(); 75 } 76 77 long count2 = mbean.getSafepointCount(); 78 long value2 = mbean.getSafepointSyncTime(); 79 80 System.out.format("Safepoint count=%d (diff=%d), sync time=%d ms (diff=%d)%n", 81 count2, count2-count1, value2, value2-value1); 82 83 if (value2 <= value1) { 84 throw new RuntimeException("Safepoint sync time " + 85 "did not increase " + 86 "(value1 = " + value1 + "; " + 87 "value2 = " + value2 + ")"); 88 } 89 90 System.out.println("Test passed."); 91 } 92 }