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 * @author Egor Ushakov
29 *
30 * @modules jdk.jdi/com.sun.tools.jdi:+open
31 *
32 * @run build TestScaffold VMConnection
33 * @run compile -g ConstantPoolInfoGC.java
34 * @run main/othervm ConstantPoolInfoGC
35 */
36
37import com.sun.jdi.ReferenceType;
38import com.sun.tools.jdi.ReferenceTypeImpl;
39
40import java.lang.ref.Reference;
41import java.lang.reflect.Field;
42import java.util.Arrays;
43
44    /********** target program **********/
45
46class ConstantPoolGCTarg {
47    public static void main(String[] args){
48        System.out.println("Anything");
49    }
50}
51
52    /********** test program **********/
53
54public 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}
105