1 /*
2 * Copyright (c) 2020, 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 8249719
27 * @summary ResolvedMethodTable hash function should take method class into account
28 * @run main/othervm/timeout=300 -Xmx256m -XX:MaxMetaspaceSize=256m ResolvedMethodTableHash 200000
29 */
30
31 import java.lang.invoke.MethodHandle;
32 import java.lang.invoke.MethodHandles;
33 import java.lang.invoke.MethodType;
34 import java.nio.ByteBuffer;
35 import java.util.ArrayList;
36 import java.util.List;
37
38 // The test generates thousands MethodHandles to the methods of the same name
39 // and the same signature. This should not take too long, unless Method hash
40 // function takes only the name and the signature as an input.
41 public class ResolvedMethodTableHash extends ClassLoader {
42
43 // Generate a MethodHandle for ClassName.m()
44 private MethodHandle generate(String className) throws ReflectiveOperationException {
45 byte[] buf = new byte[100];
46 int size = writeClass(buf, className);
47 Class<?> cls = defineClass(null, buf, 0, size);
48 return MethodHandles.publicLookup().findStatic(cls, "m", MethodType.methodType(void.class));
49 }
50
51 // Produce a class file with the given name and a single method:
52 // public static native void m();
53 private int writeClass(byte[] buf, String className) {
54 return ByteBuffer.wrap(buf)
55 .putInt(0xCAFEBABE) // magic
56 .putInt(50) // version: 50
57 .putShort((short) 7) // constant_pool_count: 7
58 .put((byte) 7).putShort((short) 2)
59 .put((byte) 1).putShort((short) className.length()).put(className.getBytes())
60 .put((byte) 7).putShort((short) 4)
61 .put((byte) 1).putShort((short) 16).put("java/lang/Object".getBytes())
62 .put((byte) 1).putShort((short) 1).put("m".getBytes())
63 .put((byte) 1).putShort((short) 3).put("()V".getBytes())
64 .putShort((short) 0x21) // access_flags: public super
65 .putShort((short) 1) // this_class: #1
66 .putShort((short) 3) // super_class: #3
67 .putShort((short) 0) // interfaces_count: 0
68 .putShort((short) 0) // fields_count: 0
69 .putShort((short) 1) // methods_count: 1
70 .putShort((short) 0x109) // access_flags: public static native
71 .putShort((short) 5) // name_index: #5
72 .putShort((short) 6) // descriptor_index: #6
73 .putShort((short) 0) // attributes_count: 0
74 .putShort((short) 0) // attributes_count: 0
75 .position();
76 }
77
78 public static void main(String[] args) throws Exception {
79 ResolvedMethodTableHash generator = new ResolvedMethodTableHash();
80 List<MethodHandle> handles = new ArrayList<>();
81
82 int count = args.length > 0 ? Integer.parseInt(args[0]) : 200000;
83
84 for (int i = 0; i < count; i++) {
85 handles.add(generator.generate("MH$" + i));
86 if (i % 1000 == 0) {
87 System.out.println("Generated " + i + " handles");
88 }
89 }
90
91 System.out.println("Test passed");
92 }
93 }