1 /*
2 * Copyright (c) 2013, 2019, 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 package gc.metaspace;
25
26 /*
27 * @test G1AddMetaspaceDependency
28 * @bug 8010196
29 * @requires vm.gc.G1
30 * @library /
31 * @summary Checks that we don't get locking problems when adding metaspace dependencies with the G1 update buffer monitor
32 * @run main/othervm -XX:+UseG1GC -XX:G1UpdateBufferSize=1 gc.metaspace.G1AddMetaspaceDependency
33 */
34
35 import java.io.InputStream;
36
37 public class G1AddMetaspaceDependency {
38
39 static byte[] getClassBytes(String name) {
40 byte[] b = null;
41 try (InputStream is = ClassLoader.getSystemResourceAsStream(name)) {
42 byte[] tmp = new byte[is.available()];
43 is.read(tmp);
44 b = tmp;
45 } finally {
46 if (b == null) {
47 throw new RuntimeException("Unable to load class file");
48 }
49 return b;
50 }
51 }
52
53 static final String a_name = A.class.getName();
54 static final String b_name = B.class.getName();
55
56 public static void main(String... args) throws Exception {
57 final byte[] a_bytes = getClassBytes(a_name.replace('.', '/') + ".class");
58 final byte[] b_bytes = getClassBytes(b_name.replace('.', '/') + ".class");
59
60 for (int i = 0; i < 1000; i += 1) {
61 runTest(a_bytes, b_bytes);
62 }
63 }
64
65 static class Loader extends ClassLoader {
66 private final String myClass;
67 private final byte[] myBytes;
68 private final String friendClass;
69 private final ClassLoader friendLoader;
70
71 Loader(String myClass, byte[] myBytes,
72 String friendClass, ClassLoader friendLoader) {
73 this.myClass = myClass;
74 this.myBytes = myBytes;
75 this.friendClass = friendClass;
76 this.friendLoader = friendLoader;
77 }
78
79 Loader(String myClass, byte[] myBytes) {
80 this(myClass, myBytes, null, null);
81 }
82
83 @Override
84 public Class<?> loadClass(String name) throws ClassNotFoundException {
85 Class<?> c = findLoadedClass(name);
86 if (c != null) {
87 return c;
88 }
89
90 if (name.equals(friendClass)) {
91 return friendLoader.loadClass(name);
92 }
93
94 if (name.equals(myClass)) {
95 c = defineClass(name, myBytes, 0, myBytes.length);
96 resolveClass(c);
97 return c;
98 }
99
100 return findSystemClass(name);
101 }
102
103 }
104
105 private static void runTest(final byte[] a_bytes, final byte[] b_bytes) throws Exception {
106 Loader a_loader = new Loader(a_name, a_bytes);
107 Loader b_loader = new Loader(b_name, b_bytes, a_name, a_loader);
108 Loader c_loader = new Loader(b_name, b_bytes, a_name, a_loader);
109 Loader d_loader = new Loader(b_name, b_bytes, a_name, a_loader);
110 Loader e_loader = new Loader(b_name, b_bytes, a_name, a_loader);
111 Loader f_loader = new Loader(b_name, b_bytes, a_name, a_loader);
112 Loader g_loader = new Loader(b_name, b_bytes, a_name, a_loader);
113
114 b_loader.loadClass(b_name);
115 c_loader.loadClass(b_name);
116 d_loader.loadClass(b_name);
117 e_loader.loadClass(b_name);
118 f_loader.loadClass(b_name);
119 g_loader.loadClass(b_name);
120 }
121 public class A {
122 }
123 class B extends A {
124 }
125 }