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 }