Mercurial > hg > truffle
comparison test/compiler/7190310/Test7190310_unsafe.java @ 6615:09aad8452938
7190310: Inlining WeakReference.get(), and hoisting $referent may lead to non-terminating loops
Summary: In C2 add software membar after load from Reference.referent field to prevent commoning of loads across safepoint since GC can change its value. In C1 always generate Reference.get() intrinsic.
Reviewed-by: roland, twisti, dholmes, johnc
author | kvn |
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date | Mon, 20 Aug 2012 09:58:58 -0700 |
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6614:006050192a5a | 6615:09aad8452938 |
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1 /* | |
2 * Copyright (c) 2012, 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 * @run main/othervm -Xbatch Test7190310_unsafe | |
30 */ | |
31 | |
32 import java.lang.ref.*; | |
33 import java.lang.reflect.*; | |
34 import sun.misc.Unsafe; | |
35 | |
36 public class Test7190310_unsafe { | |
37 | |
38 static class TestObject { | |
39 public String toString() { | |
40 return "TestObject"; | |
41 } | |
42 }; | |
43 | |
44 private static TestObject str = new TestObject(); | |
45 private static final WeakReference ref = new WeakReference(str); | |
46 | |
47 private TestObject obj; | |
48 | |
49 public static void main(String[] args) throws Exception { | |
50 Class c = Test7190310_unsafe.class.getClassLoader().loadClass("sun.misc.Unsafe"); | |
51 Field f = c.getDeclaredField("theUnsafe"); | |
52 f.setAccessible(true); | |
53 Unsafe unsafe = (Unsafe)f.get(c); | |
54 | |
55 f = Reference.class.getDeclaredField("referent"); | |
56 f.setAccessible(true); | |
57 long referent_offset = unsafe.objectFieldOffset(f); | |
58 | |
59 Test7190310_unsafe t = new Test7190310_unsafe(); | |
60 TestObject o = new TestObject(); | |
61 t.obj = o; | |
62 | |
63 // Warmup (compile methods) | |
64 System.err.println("Warmup"); | |
65 Object obj = null; | |
66 for (int i = 0; i < 11000; i++) { | |
67 obj = getRef0(ref); | |
68 } | |
69 for (int i = 0; i < 11000; i++) { | |
70 obj = getRef1(unsafe, ref, referent_offset); | |
71 } | |
72 for (int i = 0; i < 11000; i++) { | |
73 obj = getRef2(unsafe, ref, referent_offset); | |
74 } | |
75 for (int i = 0; i < 11000; i++) { | |
76 obj = getRef3(unsafe, ref, referent_offset); | |
77 } | |
78 for (int i = 0; i < 11000; i++) { | |
79 obj = getRef4(unsafe, t, referent_offset); | |
80 } | |
81 | |
82 // Access verification | |
83 System.err.println("Verification"); | |
84 if (!verifyGet(referent_offset, unsafe)) { | |
85 System.exit(97); | |
86 } | |
87 | |
88 obj = getRef3(unsafe, t, referent_offset); | |
89 if (obj != o) { | |
90 System.out.println("FAILED: unsafe.getObject(Object, " + referent_offset + ") " + obj + " != " + o); | |
91 System.exit(97); | |
92 } | |
93 obj = getRef4(unsafe, t, referent_offset); | |
94 if (obj != o) { | |
95 System.out.println("FAILED: unsafe.getObject(Test7190310, " + referent_offset + ") " + obj + " != " + o); | |
96 System.exit(97); | |
97 } | |
98 } | |
99 | |
100 static boolean verifyGet(long referent_offset, Unsafe unsafe) throws Exception { | |
101 // Access verification | |
102 System.out.println("referent: " + str); | |
103 Object obj = getRef0(ref); | |
104 if (obj != str) { | |
105 System.out.println("FAILED: weakRef.get() " + obj + " != " + str); | |
106 return false; | |
107 } | |
108 obj = getRef1(unsafe, ref, referent_offset); | |
109 if (obj != str) { | |
110 System.out.println("FAILED: unsafe.getObject(weakRef, " + referent_offset + ") " + obj + " != " + str); | |
111 return false; | |
112 } | |
113 obj = getRef2(unsafe, ref, referent_offset); | |
114 if (obj != str) { | |
115 System.out.println("FAILED: unsafe.getObject(abstRef, " + referent_offset + ") " + obj + " != " + str); | |
116 return false; | |
117 } | |
118 obj = getRef3(unsafe, ref, referent_offset); | |
119 if (obj != str) { | |
120 System.out.println("FAILED: unsafe.getObject(Object, " + referent_offset + ") " + obj + " != " + str); | |
121 return false; | |
122 } | |
123 return true; | |
124 } | |
125 | |
126 static Object getRef0(WeakReference ref) throws Exception { | |
127 return ref.get(); | |
128 } | |
129 static Object getRef1(Unsafe unsafe, WeakReference ref, long referent_offset) throws Exception { | |
130 return unsafe.getObject(ref, referent_offset); | |
131 } | |
132 static Object getRef2(Unsafe unsafe, Reference ref, long referent_offset) throws Exception { | |
133 return unsafe.getObject(ref, referent_offset); | |
134 } | |
135 static Object getRef3(Unsafe unsafe, Object ref, long referent_offset) throws Exception { | |
136 return unsafe.getObject(ref, referent_offset); | |
137 } | |
138 static Object getRef4(Unsafe unsafe, Test7190310_unsafe ref, long referent_offset) throws Exception { | |
139 return unsafe.getObject(ref, referent_offset); | |
140 } | |
141 } | |
142 |