1 /*
2 * Copyright (c) 2012, 2015, 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 /*
26 * @test
27 * @bug 7190310
28 * @summary Inlining WeakReference.get(), and hoisting $referent may lead to non-terminating loops
29 * @modules java.base/jdk.internal.misc
30 * @run main/othervm -Xbatch Test7190310_unsafe
31 */
32
33 import java.lang.ref.*;
34 import java.lang.reflect.*;
35 import jdk.internal.misc.Unsafe;
36
37 public class Test7190310_unsafe {
38
39 static class TestObject {
40 public String toString() {
41 return "TestObject";
42 }
43 };
44
45 private static TestObject str = new TestObject();
46 private static final WeakReference ref = new WeakReference(str);
47
48 private TestObject obj;
49
50 public static void main(String[] args) throws Exception {
51 Class c = Test7190310_unsafe.class.getClassLoader().loadClass("jdk.internal.misc.Unsafe");
52 Field f = c.getDeclaredField("theUnsafe");
53 f.setAccessible(true);
54 Unsafe unsafe = (Unsafe)f.get(c);
55
56 f = Reference.class.getDeclaredField("referent");
57 f.setAccessible(true);
58 long referent_offset = unsafe.objectFieldOffset(f);
59
60 Test7190310_unsafe t = new Test7190310_unsafe();
61 TestObject o = new TestObject();
62 t.obj = o;
63
64 // Warmup (compile methods)
65 System.err.println("Warmup");
66 Object obj = null;
67 for (int i = 0; i < 11000; i++) {
68 obj = getRef0(ref);
69 }
70 for (int i = 0; i < 11000; i++) {
71 obj = getRef1(unsafe, ref, referent_offset);
72 }
73 for (int i = 0; i < 11000; i++) {
74 obj = getRef2(unsafe, ref, referent_offset);
75 }
76 for (int i = 0; i < 11000; i++) {
77 obj = getRef3(unsafe, ref, referent_offset);
78 }
79 for (int i = 0; i < 11000; i++) {
80 obj = getRef4(unsafe, t, referent_offset);
81 }
82
83 // Access verification
84 System.err.println("Verification");
85 if (!verifyGet(referent_offset, unsafe)) {
86 System.exit(97);
87 }
88
89 obj = getRef3(unsafe, t, referent_offset);
90 if (obj != o) {
91 System.out.println("FAILED: unsafe.getObject(Object, " + referent_offset + ") " + obj + " != " + o);
92 System.exit(97);
93 }
94 obj = getRef4(unsafe, t, referent_offset);
95 if (obj != o) {
96 System.out.println("FAILED: unsafe.getObject(Test7190310, " + referent_offset + ") " + obj + " != " + o);
97 System.exit(97);
98 }
99 }
100
101 static boolean verifyGet(long referent_offset, Unsafe unsafe) throws Exception {
102 // Access verification
103 System.out.println("referent: " + str);
104 Object obj = getRef0(ref);
105 if (obj != str) {
106 System.out.println("FAILED: weakRef.get() " + obj + " != " + str);
107 return false;
108 }
109 obj = getRef1(unsafe, ref, referent_offset);
110 if (obj != str) {
111 System.out.println("FAILED: unsafe.getObject(weakRef, " + referent_offset + ") " + obj + " != " + str);
112 return false;
113 }
114 obj = getRef2(unsafe, ref, referent_offset);
115 if (obj != str) {
116 System.out.println("FAILED: unsafe.getObject(abstRef, " + referent_offset + ") " + obj + " != " + str);
117 return false;
118 }
119 obj = getRef3(unsafe, ref, referent_offset);
120 if (obj != str) {
121 System.out.println("FAILED: unsafe.getObject(Object, " + referent_offset + ") " + obj + " != " + str);
122 return false;
123 }
124 return true;
125 }
126
127 static Object getRef0(WeakReference ref) throws Exception {
128 return ref.get();
129 }
130 static Object getRef1(Unsafe unsafe, WeakReference ref, long referent_offset) throws Exception {
131 return unsafe.getObject(ref, referent_offset);
132 }
133 static Object getRef2(Unsafe unsafe, Reference ref, long referent_offset) throws Exception {
134 return unsafe.getObject(ref, referent_offset);
135 }
136 static Object getRef3(Unsafe unsafe, Object ref, long referent_offset) throws Exception {
137 return unsafe.getObject(ref, referent_offset);
138 }
139 static Object getRef4(Unsafe unsafe, Test7190310_unsafe ref, long referent_offset) throws Exception {
140 return unsafe.getObject(ref, referent_offset);
141 }
142 }
143