1 /*
   2  * Copyright (c) 2015, 2019, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package jdk.jfr.event.oldobject;
  26 
  27 import java.util.ArrayList;
  28 import java.util.List;
  29 
  30 import jdk.jfr.Recording;
  31 import jdk.jfr.consumer.RecordedEvent;
  32 import jdk.jfr.internal.test.WhiteBox;
  33 import jdk.testlibrary.jfr.EventNames;
  34 import jdk.testlibrary.jfr.Events;
  35 import jdk.testlibrary.jfr.OldObjects;
  36 
  37 /*
  38  * @test
  39  * @key jfr
  40  * @requires vm.gc == "null"
  41  * @library /lib/testlibrary
  42  * @modules jdk.jfr/jdk.jfr.internal.test
  43  * @run main/othervm -XX:TLABSize=2k jdk.jfr.event.oldobject.TestCircularReference
  44  */
  45 public class TestCircularReference {
  46 
  47     static class TestCircularReferrer {
  48         // Allocate array to trigger sampling code path for interpreter / c1
  49         final byte[] leak = new byte[1_0000_000];
  50         TestCircularReferrer reference;
  51 
  52         public void setReference(TestCircularReferrer reference) {
  53             this.reference = reference;
  54         }
  55     }
  56 
  57     public final static List<Object> referenceHolder = new ArrayList<>(OldObjects.MIN_SIZE);
  58 
  59     public static void main(String[] args) throws Exception {
  60         WhiteBox.setWriteAllObjectSamples(true);
  61 
  62         try (Recording r = new Recording()) {
  63             r.enable(EventNames.OldObjectSample).with("cutoff", "infinity").withStackTrace();
  64             r.start();
  65 
  66             TestCircularReferrer a = new TestCircularReferrer();
  67             TestCircularReferrer b = new TestCircularReferrer();
  68             TestCircularReferrer c = new TestCircularReferrer();
  69             a.setReference(b);
  70             b.setReference(c);
  71             c.setReference(a);
  72             referenceHolder.add(a);
  73 
  74             TestCircularReferrer selfReflector = new TestCircularReferrer();
  75             selfReflector.setReference(selfReflector);
  76             referenceHolder.add(selfReflector);
  77 
  78             r.stop();
  79 
  80             List<RecordedEvent> events = Events.fromRecording(r);
  81             if (events.isEmpty()) {
  82                 throw new AssertionError("Expected Old Object Sample events!");
  83             }
  84         }
  85     }
  86 }