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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

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 *

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 * 2 along with this work; if not, write to the Free Software Foundation,

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/*

 * @test

 * @requires vm.compMode != "Xcomp"

 * @summary Verifies behaviour of Unsafe.allocateMemory

 * @library /testlibrary

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

 *          java.management

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

 */

import jdk.test.lib.*;

import sun.misc.Unsafe;

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

public class AllocateMemory {

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

        Unsafe unsafe = Utils.getUnsafe();

        // Allocate a byte, write to the location and read back the value

        long address = unsafe.allocateMemory(1);

        assertNotEquals(address, 0L);

        unsafe.putByte(address, Byte.MAX_VALUE);

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

        unsafe.freeMemory(address);

        // Call to allocateMemory() with a negative value should result in an IllegalArgumentException

        try {

            address = unsafe.allocateMemory(-1);

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

        } catch (IllegalArgumentException e) {

            // Expected

            assertNotEquals(address, 0L);

        }

        // allocateMemory() should throw an OutOfMemoryError when the underlying malloc fails,

        // we test this by limiting the malloc using -XX:MallocMaxTestWords

        try {

            address = unsafe.allocateMemory(100 * 1024 * 1024 * 8);

        } catch (OutOfMemoryError e) {

            // Expected

            return;

        }

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

    }

}