/*

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * under the terms of the GNU General Public License version 2 only, as

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 *

 * 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.

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 */

/*

 * @test

 * @requires vm.compMode != "Xcomp"

 * @bug 8058897

 * @library /test/lib

 * @modules java.base/jdk.internal.misc

 *          java.management

 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:MallocMaxTestWords=100m Reallocate

 */

import jdk.internal.misc.Unsafe;

import static jdk.test.lib.Asserts.*;

public class Reallocate {

    public static void main(String args[]) throws Exception {

        long address = unsafe.allocateMemory(1);

        assertNotEquals(address, 0L);

        // Make sure we reallocate correctly

        unsafe.putByte(address, Byte.MAX_VALUE);

        address = unsafe.reallocateMemory(address, 2);

        assertNotEquals(address, 0L);

        assertEquals(unsafe.getByte(address), Byte.MAX_VALUE);

        // Reallocating with a 0 size should return a null pointer

        address = unsafe.reallocateMemory(address, 0);

        assertEquals(address, 0L);

        // Reallocating with a null pointer should result in a normal allocation

        address = unsafe.reallocateMemory(0L, 1);

        assertNotEquals(address, 0L);

        unsafe.putByte(address, Byte.MAX_VALUE);

        assertEquals(unsafe.getByte(address), Byte.MAX_VALUE);

        // Make sure we can throw an OOME when we fail to reallocate due to OOM

        try {

            unsafe.reallocateMemory(address, 100 * 1024 * 1024 * 8);

        } catch (OutOfMemoryError e) {

            // Expected

            return;

        }

        throw new RuntimeException("Did not get expected OOM");

    }

}