hotspot/test/compiler/unsafe/SunMiscUnsafeAccessTestObject.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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/*
 * @test
 * @bug 8143628
 * @summary Test unsafe access for Object
 *
 * @modules jdk.unsupported/sun.misc
 * @run testng/othervm -Diters=100   -Xint                   compiler.unsafe.SunMiscUnsafeAccessTestObject
 * @run testng/othervm -Diters=20000 -XX:TieredStopAtLevel=1 compiler.unsafe.SunMiscUnsafeAccessTestObject
 * @run testng/othervm -Diters=20000 -XX:-TieredCompilation  compiler.unsafe.SunMiscUnsafeAccessTestObject
 * @run testng/othervm -Diters=20000                         compiler.unsafe.SunMiscUnsafeAccessTestObject
 */

package compiler.unsafe;

import org.testng.annotations.Test;

import java.lang.reflect.Field;

import static org.testng.Assert.*;

public class SunMiscUnsafeAccessTestObject {
    static final int ITERS = Integer.getInteger("iters", 1);
    static final int WEAK_ATTEMPTS = Integer.getInteger("weakAttempts", 10);

    static final sun.misc.Unsafe UNSAFE;

    static final long V_OFFSET;

    static final Object STATIC_V_BASE;

    static final long STATIC_V_OFFSET;

    static int ARRAY_OFFSET;

    static int ARRAY_SHIFT;

    static {
        try {
            Field f = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");
            f.setAccessible(true);
            UNSAFE = (sun.misc.Unsafe) f.get(null);
        } catch (Exception e) {
            throw new RuntimeException("Unable to get Unsafe instance.", e);
        }

        try {
            Field staticVField = SunMiscUnsafeAccessTestObject.class.getDeclaredField("static_v");
            STATIC_V_BASE = UNSAFE.staticFieldBase(staticVField);
            STATIC_V_OFFSET = UNSAFE.staticFieldOffset(staticVField);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

        try {
            Field vField = SunMiscUnsafeAccessTestObject.class.getDeclaredField("v");
            V_OFFSET = UNSAFE.objectFieldOffset(vField);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

        ARRAY_OFFSET = UNSAFE.arrayBaseOffset(Object[].class);
        int ascale = UNSAFE.arrayIndexScale(Object[].class);
        ARRAY_SHIFT = 31 - Integer.numberOfLeadingZeros(ascale);
    }

    static Object static_v;

    Object v;

    @Test
    public void testFieldInstance() {
        SunMiscUnsafeAccessTestObject t = new SunMiscUnsafeAccessTestObject();
        for (int c = 0; c < ITERS; c++) {
            testAccess(t, V_OFFSET);
        }
    }

    @Test
    public void testFieldStatic() {
        for (int c = 0; c < ITERS; c++) {
            testAccess(STATIC_V_BASE, STATIC_V_OFFSET);
        }
    }

    @Test
    public void testArray() {
        Object[] array = new Object[10];
        for (int c = 0; c < ITERS; c++) {
            for (int i = 0; i < array.length; i++) {
                testAccess(array, (((long) i) << ARRAY_SHIFT) + ARRAY_OFFSET);
            }
        }
    }


    static void testAccess(Object base, long offset) {
        // Plain
        {
            UNSAFE.putObject(base, offset, "foo");
            Object x = UNSAFE.getObject(base, offset);
            assertEquals(x, "foo", "set Object value");
        }

        // Volatile
        {
            UNSAFE.putObjectVolatile(base, offset, "bar");
            Object x = UNSAFE.getObjectVolatile(base, offset);
            assertEquals(x, "bar", "putVolatile Object value");
        }

        // Lazy
        {
            UNSAFE.putOrderedObject(base, offset, "foo");
            Object x = UNSAFE.getObjectVolatile(base, offset);
            assertEquals(x, "foo", "putRelease Object value");
        }



        UNSAFE.putObject(base, offset, "foo");

        // Compare
        {
            boolean r = UNSAFE.compareAndSwapObject(base, offset, "foo", "bar");
            assertEquals(r, true, "success compareAndSwap Object");
            Object x = UNSAFE.getObject(base, offset);
            assertEquals(x, "bar", "success compareAndSwap Object value");
        }

        {
            boolean r = UNSAFE.compareAndSwapObject(base, offset, "foo", "baz");
            assertEquals(r, false, "failing compareAndSwap Object");
            Object x = UNSAFE.getObject(base, offset);
            assertEquals(x, "bar", "failing compareAndSwap Object value");
        }

        UNSAFE.putObject(base, offset, "bar");

        // Compare set and get
        {
            Object o = UNSAFE.getAndSetObject(base, offset, "foo");
            assertEquals(o, "bar", "getAndSet Object");
            Object x = UNSAFE.getObject(base, offset);
            assertEquals(x, "foo", "getAndSet Object value");
        }

    }

}