8245043: Simplified contention benchmark

Reviewed-by: shade, skuksenko

Author: Eric Caspole

test/micro/org/openjdk/bench/vm/lang/MonitorBench.java

@@ -0,0 +1,104 @@
+/*
+* Copyright (c) 2020, 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.lang;
+
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.TimeUnit;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+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.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Threads;
+import org.openjdk.jmh.infra.Blackhole;
+
+@State(Scope.Benchmark)
+@Threads(Threads.MAX)
+public class MonitorBench {
+
+    @Param({"100", "250"})
+    int consumeUnlocked;
+
+    @Param({"100", "250"})
+    int consumeLocked;
+
+    @Param({"0", "1"})
+    int throwThreshold;
+
+    @Param({"10000"})
+    int range;
+
+    @Param({"1"})
+    static int locksSize;
+
+    Object[] sharedLocks;
+
+    @Setup
+    public void setup() {
+        sharedLocks = new Object[locksSize];
+        for (int i = 0; i < locksSize; i++) {
+            sharedLocks[i] = new Object();
+        }
+    }
+
+    int update2(int sharedIndex) throws Exception {
+        synchronized (sharedLocks[sharedIndex]) {
+            Blackhole.consumeCPU(consumeLocked);
+            if (ThreadLocalRandom.current().nextInt(range) < throwThreshold) {
+                throw new Exception("Update failed");
+            } else {
+                Blackhole.consumeCPU(consumeLocked);
+                return 0;
+            }
+        }
+    }
+
+    int update1(int sharedIndex) throws Exception {
+        synchronized (sharedLocks[sharedIndex]) {
+            Blackhole.consumeCPU(consumeLocked);
+            return update2(sharedIndex);
+        }
+    }
+
+    @Benchmark
+    @BenchmarkMode(Mode.Throughput)
+    @OutputTimeUnit(TimeUnit.MILLISECONDS)
+    public int action() throws InterruptedException {
+        Blackhole.consumeCPU(consumeUnlocked);
+        int sharedLockIndex = ThreadLocalRandom.current().nextInt(locksSize);
+        Object sharedLock = sharedLocks[sharedLockIndex];
+        synchronized (sharedLock) {
+            while (true) {
+                try {
+                    return update1(sharedLockIndex);
+                } catch (Exception e) {
+                    sharedLock.wait(100);
+                }
+            }
+        }
+    }
+}