1 /*
   2  * Copyright (c) 2015, 2016, 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  * @summary Test checks output displayed with jstat -gccause.
  27  *          Test scenario:
  28  *          test several times provokes garbage collection in the debuggee application and after each garbage
  29  *          collection runs jstat. jstat should show that after garbage collection number of GC events and garbage
  30  *          collection time increase.
  31  * @modules java.base/jdk.internal.misc
  32  * @library /test/lib/share/classes
  33  * @library ../share
  34  * @requires vm.opt.ExplicitGCInvokesConcurrent != true
  35  * @build common.*
  36  * @build utils.*
  37  *
  38  * @run main/othervm -XX:+UsePerfData -Xmx128M GcCauseTest01
  39  */
  40 import utils.*;
  41 
  42 public class GcCauseTest01 {
  43 
  44     public static void main(String[] args) throws Exception {
  45 
  46         // We will be running "jstat -gc" tool
  47         JstatGcCauseTool jstatGcTool = new JstatGcCauseTool(ProcessHandle.current().getPid());
  48 
  49         // Run once and get the  results asserting that they are reasonable
  50         JstatGcCauseResults measurement1 = jstatGcTool.measure();
  51         measurement1.assertConsistency();
  52 
  53         GcProvoker gcProvoker = GcProvoker.createGcProvoker();
  54 
  55         // Provoke GC then run the tool again and get the results  asserting that they are reasonable
  56         gcProvoker.provokeGc();
  57         JstatGcCauseResults measurement2 = jstatGcTool.measure();
  58         measurement2.assertConsistency();
  59 
  60         // Assert the increase in GC events and time between the measurements
  61         JstatResults.assertGCEventsIncreased(measurement1, measurement2);
  62         JstatResults.assertGCTimeIncreased(measurement1, measurement2);
  63 
  64         // Provoke GC 3rd time then run the tool 3rd time twice and get the results
  65         // asserting that they are reasonable
  66         gcProvoker.provokeGc();
  67         JstatGcCauseResults measurement3 = jstatGcTool.measure();
  68         measurement3.assertConsistency();
  69 
  70         // Assert the increase in GC events and time between the measurements
  71         JstatResults.assertGCEventsIncreased(measurement2, measurement3);
  72         JstatResults.assertGCTimeIncreased(measurement2, measurement3);
  73     }
  74 }