1 /*
   2  * Copyright (c) 2014, 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  * @key gc
  27  * @bug 8049831
  28  * @library /testlibrary /../../test/lib
  29  * @modules java.base/sun.misc
  30  *          java.management
  31  * @build TestCapacityUntilGCWrapAround
  32  * @run main ClassFileInstaller sun.hotspot.WhiteBox
  33  *                              sun.hotspot.WhiteBox$WhiteBoxPermission
  34  * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI TestCapacityUntilGCWrapAround
  35  */
  36 
  37 import sun.hotspot.WhiteBox;
  38 
  39 import jdk.test.lib.Asserts;
  40 import jdk.test.lib.Platform;
  41 
  42 public class TestCapacityUntilGCWrapAround {
  43     private static long MB = 1024 * 1024;
  44     private static long GB = 1024 * MB;
  45     private static long MAX_UINT = 4 * GB - 1; // On 32-bit platforms
  46 
  47     public static void main(String[] args) {
  48         if (Platform.is32bit()) {
  49             WhiteBox wb = WhiteBox.getWhiteBox();
  50 
  51             long before = wb.metaspaceCapacityUntilGC();
  52             // Now force possible overflow of capacity_until_GC.
  53             long after = wb.incMetaspaceCapacityUntilGC(MAX_UINT);
  54 
  55             Asserts.assertGTE(after, before,
  56                               "Increasing with MAX_UINT should not cause wrap around: " + after + " < " + before);
  57             Asserts.assertLTE(after, MAX_UINT,
  58                               "Increasing with MAX_UINT should not cause value larger than MAX_UINT:" + after);
  59         }
  60     }
  61 }