hotspot/test/runtime/Unsafe/GetPutAddress.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * 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).
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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
 * Verify behaviour of Unsafe.get/putAddress and Unsafe.addressSize
 * @library /testlibrary
 * @modules java.base/sun.misc
 *          java.management
 * @run main GetPutAddress
 */

import com.oracle.java.testlibrary.*;
import sun.misc.Unsafe;
import static com.oracle.java.testlibrary.Asserts.*;

public class GetPutAddress {
    public static void main(String args[]) throws Exception {
        Unsafe unsafe = Utils.getUnsafe();
        int addressSize = unsafe.addressSize();
        // Ensure the size returned from Unsafe.addressSize is correct
        assertEquals(unsafe.addressSize(), Platform.is32bit() ? 4 : 8);

        // Write the address, read it back and make sure it's the same value
        long address = unsafe.allocateMemory(addressSize);
        unsafe.putAddress(address, address);
        long readAddress = unsafe.getAddress(address);
        if (addressSize == 4) {
          readAddress &= 0x00000000FFFFFFFFL;
        }
        assertEquals(address, readAddress);
        unsafe.freeMemory(address);
    }
}