/* * Copyright Amazon.com Inc. 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.*; import org.openjdk.jmh.infra.Blackhole; import java.util.concurrent.TimeUnit; @Warmup(iterations = 5, time = 300, timeUnit = TimeUnit.MILLISECONDS) @Measurement(iterations = 5, time = 300, timeUnit = TimeUnit.MILLISECONDS) @Fork(value = 3, jvmArgs = {"-XX:+TieredCompilation", "-XX:TieredStopAtLevel=1"}) @BenchmarkMode(Mode.AverageTime) @OutputTimeUnit(TimeUnit.NANOSECONDS) @Threads(Threads.MAX) @State(Scope.Benchmark) public class SecondarySuperCacheInterContention { // This test targets C1 specifically, to enter the interesting code path // without heavily optimizing compiler like C2 optimizing based on profiles, // or folding the instanceof checks. // The test verifies what happens on unhappy path, when we contend a lot over // the secondary super cache, where different threads want to update the cache // with different value. In tihs test, every thread comes with its own stable // cached value. Meaning, this tests the INTER-thread contention. interface IA {} interface IB {} class B {} class C1 extends B implements IA, IB {} class C2 extends B implements IA, IB {} volatile B o1, o2; @Setup public void setup() { o1 = new C1(); o2 = new C2(); } @Benchmark @OperationsPerInvocation(2) @Group("test") @GroupThreads(1) public void t1(Blackhole bh) { bh.consume(o1 instanceof IA); bh.consume(o2 instanceof IA); } @Benchmark @OperationsPerInvocation(2) @Group("test") @GroupThreads(1) public void t2(Blackhole bh) { bh.consume(o1 instanceof IB); bh.consume(o2 instanceof IB); } }