1 /*
 2  * Copyright Amazon.com Inc. 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 package org.openjdk.bench.java.lang.ref;
24 
25 import java.lang.ref.Cleaner;
26 import java.lang.ref.Cleaner.Cleanable;
27 import java.util.ArrayList;
28 import java.util.concurrent.ThreadLocalRandom;
29 import java.util.concurrent.TimeUnit;
30 import org.openjdk.jmh.annotations.*;
31 import org.openjdk.jmh.infra.Blackhole;
32 
33 @OutputTimeUnit(TimeUnit.MILLISECONDS)
34 @State(Scope.Thread)
35 @BenchmarkMode(Mode.AverageTime)
36 @Warmup(iterations = 3, time = 1, timeUnit = TimeUnit.SECONDS)
37 @Measurement(iterations = 3, time = 1, timeUnit = TimeUnit.SECONDS)
38 @Fork(value = 3, jvmArgs = {"-Xmx1g", "-Xms1g", "-XX:+AlwaysPreTouch"})
39 public class CleanerGC {
40 
41     @Param({"16384", "65536", "262144", "1048576", "4194304"})
42     int count;
43 
44     // Make sure all targets are reachable and available for GC in scalable manner.
45     // This exposes the potential GC problem in Cleaner lists.
46     ArrayList<Target> targets;
47 
48     @Setup
49     public void setup() {
50         targets = new ArrayList<>();
51         for (int c = 0; c < count; c++) {
52             targets.add(new Target());
53         }
54     }
55 
56     @Benchmark
57     public void test() {
58         System.gc();
59     }
60 
61     static class Target {
62         private static final Cleaner CLEANER = Cleaner.create();
63         @SuppressWarnings("initialization")
64         public Target() {
65             CLEANER.register(this, () -> {});
66         }
67     }
68 
69 }
--- EOF ---