1 /*

     2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.

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

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

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

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 /*

    25  * @test

    26  * @summary Make sure pageSize() returns a value that is a power of two

    27  * @library /testlibrary

    28  * @run main PageSize

    29  */

    30 

    31 import java.lang.reflect.Field;

    32 import com.oracle.java.testlibrary.*;

    33 import sun.misc.Unsafe;

    34 import static com.oracle.java.testlibrary.Asserts.*;

    35 

    36 public class PageSize {

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

    38         Unsafe unsafe = Utils.getUnsafe();

    39         int pageSize = unsafe.pageSize();

    40 

    41         for (int n = 1; n != 0; n <<= 1) {

    42             if (pageSize == n) {

    43                 return;

    44             }

    45         }

    46         throw new RuntimeException("Expected pagesize to be a power of two, actual pagesize:" + pageSize);

    47     }

    48 }