Dummy benchmark

test/micro/org/openjdk/bench/java/lang/foreign/SingleShotWrite.java

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+/*
+ * Copyright (c) 2025, 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.java.lang.foreign;
+
+import java.lang.foreign.Arena;
+import java.lang.foreign.MemoryLayout;
+import java.lang.foreign.MemorySegment;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.VarHandle;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.util.concurrent.TimeUnit;
+
+import jdk.internal.misc.Unsafe;
+import org.openjdk.jmh.annotations.*;
+
+import static java.lang.foreign.ValueLayout.*;
+
+@BenchmarkMode(Mode.SingleShotTime)
+@Warmup(iterations = 5, time = 500, timeUnit = TimeUnit.MILLISECONDS)
+@Measurement(iterations = 10, time = 500, timeUnit = TimeUnit.MILLISECONDS)
+@State(org.openjdk.jmh.annotations.Scope.Thread)
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+@Fork(value = 3, jvmArgs = { "--add-opens=java.base/jdk.internal.misc=ALL-UNNAMED", "-XX:TieredStopAtLevel=1" })
+public class SingleShotWrite extends JavaLayouts {
+
+    static final Unsafe unsafe = Utils.unsafe;
+
+    static final int ELEM_SIZE = 1_000_000;
+    static final int CARRIER_SIZE = (int)JAVA_INT.byteSize();
+    static final int ALLOC_SIZE = ELEM_SIZE * CARRIER_SIZE;
+
+    Arena arena;
+    MemorySegment segment;
+    long unsafe_addr;
+
+    ByteBuffer byteBuffer;
+
+    @Setup
+    public void setup() {
+        unsafe_addr = unsafe.allocateMemory(ALLOC_SIZE);
+        arena = Arena.ofConfined();
+        segment = arena.allocate(ALLOC_SIZE, 1);
+        //VH_INT.set(segment, 0L, 0);
+        byteBuffer = ByteBuffer.allocateDirect(ALLOC_SIZE).order(ByteOrder.nativeOrder());
+    }
+
+    @TearDown
+    public void tearDown() {
+        arena.close();
+        unsafe.invokeCleaner(byteBuffer);
+        unsafe.freeMemory(unsafe_addr);
+    }
+
+    @Benchmark
+    public int unsafe() {
+        for (int i = 0; i < ELEM_SIZE; i++) {
+            unsafe.putInt(unsafe_addr + (i * CARRIER_SIZE) , i);
+        }
+        return unsafe.getInt(unsafe_addr);
+    }
+
+    @Benchmark
+    public int segment() {
+        for (int i = 0; i < ELEM_SIZE; i++) {
+            VH_INT.set(segment, (long) i, i);
+        }
+        return (int) VH_INT.get(segment, 0L);
+    }
+
+    @Benchmark
+    public int BB() {
+        for (int i = 0; i < ELEM_SIZE; i++) {
+            byteBuffer.putInt(i * CARRIER_SIZE , i);
+        }
+        return byteBuffer.getInt(0);
+    }
+
+}