|
1 /* |
|
2 * Copyright (c) 2003, 2008, 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. Oracle designates this |
|
8 * particular file as subject to the "Classpath" exception as provided |
|
9 * by Oracle in the LICENSE file that accompanied this code. |
|
10 * |
|
11 * This code is distributed in the hope that it will be useful, but WITHOUT |
|
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
|
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
|
14 * version 2 for more details (a copy is included in the LICENSE file that |
|
15 * accompanied this code). |
|
16 * |
|
17 * You should have received a copy of the GNU General Public License version |
|
18 * 2 along with this work; if not, write to the Free Software Foundation, |
|
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
|
20 * |
|
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
|
22 * or visit www.oracle.com if you need additional information or have any |
|
23 * questions. |
|
24 */ |
|
25 |
|
26 /* |
|
27 * Copyright 2003 Wily Technology, Inc. |
|
28 */ |
|
29 |
|
30 #include <jni.h> |
|
31 #include <jvmti.h> |
|
32 |
|
33 #include "JPLISAssert.h" |
|
34 #include "Reentrancy.h" |
|
35 #include "JPLISAgent.h" |
|
36 |
|
37 /* |
|
38 * This module provides some utility functions to support the "same thread" re-entrancy management. |
|
39 * Uses JVMTI TLS to store a single bit per thread. |
|
40 * Non-zero means the thread is already inside; zero means the thread is not inside. |
|
41 */ |
|
42 |
|
43 /* |
|
44 * Local prototypes |
|
45 */ |
|
46 |
|
47 /* Wrapper around set that does the set then re-fetches to make sure it worked. |
|
48 * Degenerates to a simple set when assertions are disabled. |
|
49 * This routine is only here because of a bug in the JVMTI where set to 0 fails. |
|
50 */ |
|
51 jvmtiError |
|
52 confirmingTLSSet( jvmtiEnv * jvmtienv, |
|
53 jthread thread, |
|
54 const void * newValue); |
|
55 |
|
56 /* Confirmation routine only; used to assure that the TLS slot holds the value we expect it to. */ |
|
57 void |
|
58 assertTLSValue( jvmtiEnv * jvmtienv, |
|
59 jthread thread, |
|
60 const void * expected); |
|
61 |
|
62 |
|
63 #define JPLIS_CURRENTLY_INSIDE_TOKEN ((void *) 0x7EFFC0BB) |
|
64 #define JPLIS_CURRENTLY_OUTSIDE_TOKEN ((void *) 0) |
|
65 |
|
66 |
|
67 jvmtiError |
|
68 confirmingTLSSet( jvmtiEnv * jvmtienv, |
|
69 jthread thread, |
|
70 const void * newValue) { |
|
71 jvmtiError error; |
|
72 |
|
73 error = (*jvmtienv)->SetThreadLocalStorage( |
|
74 jvmtienv, |
|
75 thread, |
|
76 newValue); |
|
77 check_phase_ret_blob(error, error); |
|
78 |
|
79 #if JPLISASSERT_ENABLEASSERTIONS |
|
80 assertTLSValue( jvmtienv, |
|
81 thread, |
|
82 newValue); |
|
83 #endif |
|
84 |
|
85 return error; |
|
86 } |
|
87 |
|
88 void |
|
89 assertTLSValue( jvmtiEnv * jvmtienv, |
|
90 jthread thread, |
|
91 const void * expected) { |
|
92 jvmtiError error; |
|
93 void * test = (void *) 0x99999999; |
|
94 |
|
95 /* now check if we do a fetch we get what we wrote */ |
|
96 error = (*jvmtienv)->GetThreadLocalStorage( |
|
97 jvmtienv, |
|
98 thread, |
|
99 &test); |
|
100 check_phase_ret(error); |
|
101 jplis_assert(error == JVMTI_ERROR_NONE); |
|
102 jplis_assert(test == expected); |
|
103 } |
|
104 |
|
105 jboolean |
|
106 tryToAcquireReentrancyToken( jvmtiEnv * jvmtienv, |
|
107 jthread thread) { |
|
108 jboolean result = JNI_FALSE; |
|
109 jvmtiError error = JVMTI_ERROR_NONE; |
|
110 void * storedValue = NULL; |
|
111 |
|
112 error = (*jvmtienv)->GetThreadLocalStorage( |
|
113 jvmtienv, |
|
114 thread, |
|
115 &storedValue); |
|
116 check_phase_ret_false(error); |
|
117 jplis_assert(error == JVMTI_ERROR_NONE); |
|
118 if ( error == JVMTI_ERROR_NONE ) { |
|
119 /* if this thread is already inside, just return false and short-circuit */ |
|
120 if ( storedValue == JPLIS_CURRENTLY_INSIDE_TOKEN ) { |
|
121 result = JNI_FALSE; |
|
122 } |
|
123 else { |
|
124 /* stuff in the sentinel and return true */ |
|
125 #if JPLISASSERT_ENABLEASSERTIONS |
|
126 assertTLSValue( jvmtienv, |
|
127 thread, |
|
128 JPLIS_CURRENTLY_OUTSIDE_TOKEN); |
|
129 #endif |
|
130 error = confirmingTLSSet ( jvmtienv, |
|
131 thread, |
|
132 JPLIS_CURRENTLY_INSIDE_TOKEN); |
|
133 check_phase_ret_false(error); |
|
134 jplis_assert(error == JVMTI_ERROR_NONE); |
|
135 if ( error != JVMTI_ERROR_NONE ) { |
|
136 result = JNI_FALSE; |
|
137 } |
|
138 else { |
|
139 result = JNI_TRUE; |
|
140 } |
|
141 } |
|
142 } |
|
143 return result; |
|
144 } |
|
145 |
|
146 |
|
147 void |
|
148 releaseReentrancyToken( jvmtiEnv * jvmtienv, |
|
149 jthread thread) { |
|
150 jvmtiError error = JVMTI_ERROR_NONE; |
|
151 |
|
152 /* assert we hold the token */ |
|
153 #if JPLISASSERT_ENABLEASSERTIONS |
|
154 assertTLSValue( jvmtienv, |
|
155 thread, |
|
156 JPLIS_CURRENTLY_INSIDE_TOKEN); |
|
157 #endif |
|
158 |
|
159 error = confirmingTLSSet( jvmtienv, |
|
160 thread, |
|
161 JPLIS_CURRENTLY_OUTSIDE_TOKEN); |
|
162 check_phase_ret(error); |
|
163 jplis_assert(error == JVMTI_ERROR_NONE); |
|
164 |
|
165 } |