jdk-24/test/micro/org/openjdk/bench/sun/misc/UnsafeOps.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package org.openjdk.bench.sun.misc;

import java.lang.reflect.Field;
import java.util.concurrent.TimeUnit;
import jdk.internal.misc.Unsafe;
import org.openjdk.jmh.annotations.*;

@BenchmarkMode(Mode.AverageTime)
@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.NANOSECONDS)
@SuppressWarnings("removal")
public class UnsafeOps {
    static final Unsafe U;
    static {
        try {
            Field f = Unsafe.class.getDeclaredField("theUnsafe");
            f.setAccessible(true);
            U = (Unsafe) f.get(null);
        } catch (ReflectiveOperationException ex) {
            throw new IllegalStateException();
        }
    }

    private static class TestClass {
        long value;
    }

    private Object object;
    private long valueOffset;
    private long address;

    @Setup
    public void setup() throws Exception {
        object = new TestClass();
        Field f = TestClass.class.getDeclaredField("value");
        valueOffset = U.objectFieldOffset(f);

        address = U.allocateMemory(1000);
    }

    @TearDown
    public void finish() {
        U.freeMemory(address);
    }

    @Benchmark
    public void putLongOnHeap() {
        U.putLong(object, 0, 99);
    }

    @Benchmark
    public long getLongOnHeap() {
        return U.getLong(object, 0);
    }

    @Benchmark
    public void putLongOffHeap() {
        U.putLong(null, address, 99);
    }

    @Benchmark
    public long getLongOffHeap() {
        return U.getLong(null, address);
    }
}