1 /*
   2  * Copyright (c) 2015, 2018, 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.test.lib.jfr.EventNames;
  34 import jdk.test.lib.jfr.Events;
  35 
  36 /*
  37  * @test
  38  * @key jfr
  39  * @requires vm.gc == "null"
  40  * @library /test/lib /test/jdk
  41  * @modules jdk.jfr/jdk.jfr.internal.test
  42  * @run main/othervm -XX:TLABSize=2k jdk.jfr.event.oldobject.TestCircularReference
  43  */
  44 public class TestCircularReference {
  45 
  46     static class TestCircularReferrer {
  47         // Allocate array to trigger sampling code path for interpreter / c1
  48         final byte[] leak = new byte[1_0000_000];
  49         TestCircularReferrer reference;
  50 
  51         public void setReference(TestCircularReferrer reference) {
  52             this.reference = reference;
  53         }
  54     }
  55 
  56     public final static List<Object> referenceHolder = new ArrayList<>(OldObjects.MIN_SIZE);
  57 
  58     public static void main(String[] args) throws Exception {
  59         WhiteBox.setWriteAllObjectSamples(true);
  60 
  61         try (Recording r = new Recording()) {
  62             r.enable(EventNames.OldObjectSample).with("cutoff", "infinity").withStackTrace();
  63             r.start();
  64 
  65             TestCircularReferrer a = new TestCircularReferrer();
  66             TestCircularReferrer b = new TestCircularReferrer();
  67             TestCircularReferrer c = new TestCircularReferrer();
  68             a.setReference(b);
  69             b.setReference(c);
  70             c.setReference(a);
  71             referenceHolder.add(a);
  72 
  73             TestCircularReferrer selfReflector = new TestCircularReferrer();
  74             selfReflector.setReference(selfReflector);
  75             referenceHolder.add(selfReflector);
  76 
  77             r.stop();
  78 
  79             List<RecordedEvent> events = Events.fromRecording(r);
  80             if (events.isEmpty()) {
  81                 throw new AssertionError("Expected Old Object Sample events!");
  82             }
  83         }
  84     }
  85 }