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 import java.util.concurrent.BrokenBarrierException;
  30 import java.util.concurrent.CyclicBarrier;
  31 
  32 import jdk.jfr.Recording;
  33 import jdk.jfr.consumer.RecordedClass;
  34 import jdk.jfr.consumer.RecordedEvent;
  35 import jdk.jfr.consumer.RecordedObject;
  36 import jdk.jfr.internal.test.WhiteBox;
  37 import jdk.testlibrary.Asserts;
  38 import jdk.testlibrary.jfr.EventNames;
  39 import jdk.testlibrary.jfr.Events;
  40 import jdk.testlibrary.jfr.OldObjects;
  41 
  42 /*
  43  * @test
  44  * @key jfr
  45  * @requires vm.gc == "null"
  46  * @library /lib/testlibrary
  47  * @modules jdk.jfr/jdk.jfr.internal.test
  48  * @run main/othervm -XX:TLABSize=2k -XX:-FastTLABRefill jdk.jfr.event.oldobject.TestLargeRootSet
  49  */
  50 public class TestLargeRootSet {
  51 
  52     private static final int THREAD_COUNT = 50;
  53 
  54     private static class RootThread extends Thread {
  55         private final CyclicBarrier barrier;
  56         private int maxDepth = OldObjects.MIN_SIZE / THREAD_COUNT;
  57 
  58         public List<StackObject[]> temporaries = new ArrayList<>(maxDepth);
  59 
  60         RootThread(CyclicBarrier cb) {
  61             this.barrier = cb;
  62         }
  63 
  64         public void run() {
  65             buildRootObjects();
  66         }
  67 
  68         private void buildRootObjects() {
  69             if (maxDepth-- > 0) {
  70                 // Allocate array to trigger sampling code path for interpreter / c1
  71                 StackObject[] stackObject = new StackObject[0];
  72                 temporaries.add(stackObject); // make sure object escapes
  73                 buildRootObjects();
  74             } else {
  75                 temporaries.clear();
  76                 try {
  77                     barrier.await(); // wait for gc
  78                     barrier.await(); // wait for recording to be stopped
  79                 } catch (InterruptedException e) {
  80                     System.err.println("Thread was unexpected interrupted: " + e.getMessage());
  81                 } catch (BrokenBarrierException e) {
  82                     System.err.println("Unexpected barrier exception: " + e.getMessage());
  83                 }
  84                 return;
  85             }
  86         }
  87     }
  88 
  89     private static class StackObject {
  90     }
  91 
  92     public static void main(String[] args) throws Exception {
  93         WhiteBox.setWriteAllObjectSamples(true);
  94 
  95         List<RootThread> threads = new ArrayList<>();
  96         try (Recording r = new Recording()) {
  97             r.enable(EventNames.OldObjectSample).withStackTrace().with("cutoff", "infinity");
  98             r.start();
  99             CyclicBarrier cb = new CyclicBarrier(THREAD_COUNT + 1);
 100             for (int i = 0; i < THREAD_COUNT; i++) {
 101                 RootThread t = new RootThread(cb);
 102                 t.start();
 103                 if (i % 10 == 0) {
 104                     // Give threads some breathing room before starting next batch
 105                     Thread.sleep(100);
 106                 }
 107                 threads.add(t);
 108             }
 109             cb.await();
 110             System.gc();
 111             r.stop();
 112             cb.await();
 113             List<RecordedEvent> events = Events.fromRecording(r);
 114             Events.hasEvents(events);
 115             for (RecordedEvent e : events) {
 116                 RecordedObject ro = e.getValue("object");
 117                 RecordedClass rc = ro.getValue("type");
 118                 System.out.println(rc.getName());
 119                 if (rc.getName().equals(StackObject[].class.getName())) {
 120                     return; // ok
 121                 }
 122             }
 123             Asserts.fail("Could not find root object");
 124         }
 125     }
 126 }
 127