Add a benchmark for opening and closing shared/confined native/heap memory segments

src/test/java/io/netty/buffer/api/benchmarks/MemorySegmentCloseBenchmark.java

@@ -0,0 +1,94 @@
+/*
+ * Copyright 2019 The Netty Project
+ *
+ * The Netty Project licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package io.netty.buffer.api.benchmarks;
+
+import jdk.incubator.foreign.MemorySegment;
+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.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.TearDown;
+import org.openjdk.jmh.annotations.Warmup;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
+@Warmup(iterations = 10, time = 1)
+@Measurement(iterations = 10, time = 1)
+@Fork(value = 5, jvmArgsAppend = { "-XX:+UnlockDiagnosticVMOptions", "-XX:+DebugNonSafepoints" })
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@State(Scope.Benchmark)
+public class MemorySegmentCloseBenchmark {
+    @Param({"0", "10", "100"})
+    public int unrelatedThreads;
+
+    @Param({"16"/*, "124", "1024"*/})
+    public int size;
+
+    public ExecutorService unrelatedThreadPool;
+    public byte[] array;
+
+    @Setup
+    public void setUp() {
+        unrelatedThreadPool = unrelatedThreads > 0? Executors.newFixedThreadPool(unrelatedThreads) : null;
+        array = new byte[size];
+    }
+
+    @TearDown
+    public void tearDown() throws InterruptedException {
+        if (unrelatedThreadPool != null) {
+            unrelatedThreadPool.shutdown();
+            unrelatedThreadPool.awaitTermination(1, TimeUnit.MINUTES);
+            unrelatedThreadPool = null;
+        }
+    }
+
+    @Benchmark
+    public MemorySegment heapConfined() {
+        try (MemorySegment segment = MemorySegment.ofArray(array)) {
+            return segment;
+        }
+    }
+
+    @Benchmark
+    public MemorySegment heapShared() {
+        try (MemorySegment segment = MemorySegment.ofArray(array).share()) {
+            return segment;
+        }
+    }
+
+    @Benchmark
+    public MemorySegment nativeConfined() {
+        try (MemorySegment segment = MemorySegment.allocateNative(size)) {
+            return segment;
+        }
+    }
+
+    @Benchmark
+    public MemorySegment nativeShared() {
+        try (MemorySegment segment = MemorySegment.allocateNative(size).share()) {
+            return segment;
+        }
+    }
+}