jdk-24/test/micro/org/openjdk/bench/vm/compiler/Explosion.java
2022-08-03 18:01:26 +00:00

75 lines
2.5 KiB
Java

/*
* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package org.openjdk.bench.vm.compiler;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Warmup;
import org.openjdk.jmh.infra.Blackhole;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.concurrent.TimeUnit;
/**
* Tests that the JVM performs object explosion (or some sort of stack allocation).
*/
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@State(Scope.Thread)
@Warmup(iterations = 4, time = 2, timeUnit = TimeUnit.SECONDS)
@Measurement(iterations = 4, time = 2, timeUnit = TimeUnit.SECONDS)
@Fork(value = 3)
public class Explosion {
@Param("5")
private int len;
@Benchmark
public void testHashtableExplosion(Blackhole bh) throws Exception {
Object o = new Object();
Object[] oa = new Object[len];
for (int i = 0; i < len; i++) {
oa[i] = new Object();
}
Hashtable<Object, Object> h = new Hashtable<>();
for (int i = 0; i < len; i++) {
h.put(oa[i], o);
}
Enumeration<Object> e = h.elements();
while (e.hasMoreElements()) {
bh.consume(e.nextElement());
}
}
}