1 /*

     2  * Copyright (c) 2016, 2018, Red Hat, Inc. 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 TestNullCheck

    26  * @summary implicit null check on brooks pointer must not cause crash

    27  * @key gc

    28  * @requires vm.gc.Shenandoah

    29  * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:-TieredCompilation

    30  *                   -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC

    31  *                   -Xmx4G -XX:HeapBaseMinAddress=0x800000000 TestNullCheck

    32  */

    33 

    34 // HeapBaseMinAddress above forces compressed oops with a base

    35 

    36 public class TestNullCheck {

    37 

    38     int f;

    39 

    40     static int test1(TestNullCheck o) {

    41         return o.f;

    42     }

    43 

    44     static TestNullCheck static_obj = new TestNullCheck();

    45 

    46     static int test2() {

    47         return static_obj.f;

    48     }

    49 

    50     static public void main(String[] args) {

    51         TestNullCheck o = new TestNullCheck();

    52         for (int i = 0; i < 20000; i++) {

    53             test1(o);

    54             test2();

    55         }

    56         try {

    57             test1(null);

    58         } catch (NullPointerException npe) {}

    59         static_obj = null;

    60         try {

    61             test2();

    62         } catch (NullPointerException npe) {}

    63     }

    64 }