| /* |
| * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * @test |
| * @bug 4858522 8174734 |
| * @summary Basic unit test of HotspotRuntimeMBean.getSafepointSyncTime() |
| * @author Steve Bohne |
| * |
| * @run main/othervm -XX:+UsePerfData GetSafepointSyncTime |
| */ |
| |
| /* |
| * This test is just a sanity check and does not check for the correct value. |
| */ |
| |
| import sun.management.*; |
| |
| public class GetSafepointSyncTime { |
| |
| private static HotspotRuntimeMBean mbean = |
| (HotspotRuntimeMBean)ManagementFactoryHelper.getHotspotRuntimeMBean(); |
| |
| private static final long NUM_THREAD_DUMPS = 300; |
| |
| static void checkPositive(long value, String label) { |
| if (value < 0) |
| throw new RuntimeException(label + " had a negative value of " |
| + value); |
| } |
| |
| static void validate(long count1, long count2, long time1, long time2, |
| String label) { |
| checkPositive(count1, label + ":count1"); |
| checkPositive(count2, label + ":count2"); |
| checkPositive(time1, label + ":time1"); |
| checkPositive(time2, label + ":time2"); |
| |
| long countDiff = count2 - count1; |
| long timeDiff = time2 - time1; |
| |
| if (countDiff < NUM_THREAD_DUMPS) { |
| throw new RuntimeException(label + |
| ": Expected at least " + NUM_THREAD_DUMPS + |
| " safepoints but only got " + countDiff); |
| } |
| |
| // getSafepointSyncTime is the accumulated time spent getting to a |
| // safepoint, so each safepoint will add a little to this, but the |
| // resolution is only milliseconds so we may not see it. |
| if (timeDiff < 0) { |
| throw new RuntimeException(label + ": Safepoint sync time " + |
| "decreased unexpectedly " + |
| "(time1 = " + time1 + "; " + |
| "time2 = " + time2 + ")"); |
| } |
| |
| System.out.format("%s: Safepoint count=%d (diff=%d), sync time=%d ms (diff=%d)%n", |
| label, count2, countDiff, time2, timeDiff); |
| |
| } |
| |
| public static void main(String args[]) throws Exception { |
| long count = mbean.getSafepointCount(); |
| long time = mbean.getSafepointSyncTime(); |
| |
| checkPositive(count, "count"); |
| checkPositive(time, "time"); |
| |
| // Thread.getAllStackTraces() should cause a safepoint. |
| |
| for (int i = 0; i < NUM_THREAD_DUMPS; i++) { |
| Thread.getAllStackTraces(); |
| } |
| |
| long count1 = mbean.getSafepointCount(); |
| long time1 = mbean.getSafepointSyncTime(); |
| |
| validate(count, count1, time, time1, "Pass 1"); |
| |
| // repeat the experiment |
| |
| for (int i = 0; i < NUM_THREAD_DUMPS; i++) { |
| Thread.getAllStackTraces(); |
| } |
| |
| long count2 = mbean.getSafepointCount(); |
| long time2 = mbean.getSafepointSyncTime(); |
| |
| validate(count1, count2, time1, time2, "Pass 2"); |
| |
| System.out.println("Test passed."); |
| } |
| } |