1 /*

     2  * Copyright (c) 2016, 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  *  @bug 6822627

    27  *  @summary Test that ReferenceType.constantPool does not produce an NPE

    28  *

    29  *  @author Egor Ushakov

    30  *

    31  *  @modules jdk.jdi/com.sun.tools.jdi

    32  *  @run build TestScaffold VMConnection

    33  *  @run compile -g ConstantPoolInfoGC.java

    34  *  @run main/othervm ConstantPoolInfoGC

    35  */

    36 

    37 import com.sun.jdi.ReferenceType;

    38 import com.sun.tools.jdi.ReferenceTypeImpl;

    39 

    40 import java.lang.ref.Reference;

    41 import java.lang.reflect.Field;

    42 import java.util.Arrays;

    43 

    44     /********** target program **********/

    45 

    46 class ConstantPoolGCTarg {

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

    48         System.out.println("Anything");

    49     }

    50 }

    51 

    52     /********** test program **********/

    53 

    54 public class ConstantPoolInfoGC extends TestScaffold {

    55     ReferenceType targetClass;

    56 

    57     ConstantPoolInfoGC(String args[]) {

    58         super(args);

    59     }

    60 

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

    62         new ConstantPoolInfoGC(args).startTests();

    63     }

    64 

    65     /********** test core **********/

    66 

    67     protected void runTests() throws Exception {

    68         targetClass = startToMain("ConstantPoolGCTarg").location().declaringType();

    69 

    70         if (vm().canGetConstantPool()) {

    71             byte[] cpbytes = targetClass.constantPool();

    72 

    73             // imitate SoftReference cleared

    74             Field constantPoolBytesRef = ReferenceTypeImpl.class.getDeclaredField("constantPoolBytesRef");

    75             constantPoolBytesRef.setAccessible(true);

    76             Reference softRef = (Reference) constantPoolBytesRef.get(targetClass);

    77             softRef.clear();

    78 

    79             byte[] cpbytes2 = targetClass.constantPool();

    80             if (!Arrays.equals(cpbytes, cpbytes2)) {

    81                 failure("Consequent constantPool results vary, first was : " + cpbytes + ", now: " + cpbytes2);

    82             };

    83 

    84         } else {

    85             System.out.println("can get constant pool version not supported");

    86         }

    87 

    88 

    89         /*

    90          * resume until end

    91          */

    92         listenUntilVMDisconnect();

    93 

    94         /*

    95          * deal with results of test

    96          * if anything has called failure("foo") testFailed will be true

    97          */

    98         if (!testFailed) {

    99             println("ConstantPoolInfoGC: passed");

   100         } else {

   101             throw new Exception("ConstantPoolInfoGC: failed");

   102         }

   103     }

   104 }