1 /*
   2  * Copyright (c) 2018, Google 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 package MyPackage;
  25 
  26 import java.util.List;
  27 
  28 /**
  29  * @test
  30  * @build Frame HeapMonitor
  31  * @summary Verifies the default GC with the Heap Monitor event system.
  32  * @compile HeapMonitorGCTest.java
  33  * @run main/othervm/native -agentlib:HeapMonitor MyPackage.HeapMonitorGCTest
  34  */
  35 
  36 /**
  37  * This test is checking that various GCs work as intended: events are sent, forcing GC works, etc.
  38  */
  39 public class HeapMonitorGCTest {
  40   public static void main(String[] args) {
  41     if (!HeapMonitor.eventStorageIsEmpty()) {
  42       throw new RuntimeException("Statistics should be null to begin with.");
  43     }
  44 
  45     HeapMonitor.enableSamplingRate();
  46 
  47     List<Frame> frameList = HeapMonitor.allocate();
  48     frameList.add(new Frame("main", "([Ljava/lang/String;)V", "HeapMonitorGCTest.java", 47));
  49     Frame[] frames = frameList.toArray(new Frame[0]);
  50 
  51     if (!HeapMonitor.obtainedEvents(frames)) {
  52       throw new RuntimeException("No expected events were found.");
  53     }
  54 
  55     HeapMonitor.forceGarbageCollection();
  56 
  57     if (!HeapMonitor.garbageContains(frames)) {
  58       throw new RuntimeException("Forcing GC did not work, not a single object was collected.");
  59     }
  60   }
  61 }