1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/test/gc/7072527/TestFullGCCount.java Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,91 @@
1.4 +/*
1.5 + * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + */
1.26 +
1.27 +/*
1.28 + * @test TestFullGCount.java
1.29 + * @bug 7072527
1.30 + * @summary CMS: JMM GC counters overcount in some cases
1.31 + * @run main/othervm -XX:+PrintGC TestFullGCCount
1.32 + */
1.33 +import java.util.*;
1.34 +import java.lang.management.*;
1.35 +
1.36 +/*
1.37 + * Originally for a specific failure in CMS, this test now monitors all
1.38 + * collectors for double-counting of collections.
1.39 + */
1.40 +public class TestFullGCCount {
1.41 +
1.42 + static List<GarbageCollectorMXBean> collectors = ManagementFactory.getGarbageCollectorMXBeans();
1.43 +
1.44 + public static void main(String[] args) {
1.45 + int iterations = 20;
1.46 + boolean failed = false;
1.47 + String errorMessage = "";
1.48 + HashMap<String, List> counts = new HashMap<String, List>();
1.49 +
1.50 + // Prime the collection of count lists for all collectors.
1.51 + for (int i = 0; i < collectors.size(); i++) {
1.52 + GarbageCollectorMXBean collector = collectors.get(i);
1.53 + counts.put(collector.getName(), new ArrayList<Long>(iterations));
1.54 + }
1.55 +
1.56 + // Perform some gc, record collector counts.
1.57 + for (int i = 0; i < iterations; i++) {
1.58 + System.gc();
1.59 + addCollectionCount(counts, i);
1.60 + }
1.61 +
1.62 + // Check the increments:
1.63 + // Old gen collectors should increase by one,
1.64 + // New collectors may or may not increase.
1.65 + // Any increase >=2 is unexpected.
1.66 + for (String collector : counts.keySet()) {
1.67 + System.out.println("Checking: " + collector);
1.68 +
1.69 + for (int i = 0; i < iterations - 1; i++) {
1.70 + List<Long> theseCounts = counts.get(collector);
1.71 + long a = theseCounts.get(i);
1.72 + long b = theseCounts.get(i + 1);
1.73 + if (b - a >= 2) {
1.74 + failed = true;
1.75 + errorMessage += "Collector '" + collector + "' has increment " + (b - a) +
1.76 + " at iteration " + i + "\n";
1.77 + }
1.78 + }
1.79 + }
1.80 + if (failed) {
1.81 + System.err.println(errorMessage);
1.82 + throw new RuntimeException("FAILED: System.gc collections miscounted.");
1.83 + }
1.84 + System.out.println("Passed.");
1.85 + }
1.86 +
1.87 + private static void addCollectionCount(HashMap<String, List> counts, int iteration) {
1.88 + for (int i = 0; i < collectors.size(); i++) {
1.89 + GarbageCollectorMXBean collector = collectors.get(i);
1.90 + List thisList = counts.get(collector.getName());
1.91 + thisList.add(collector.getCollectionCount());
1.92 + }
1.93 + }
1.94 +}
