1 /*
2 * pthread_mutex_lock.c
3 *
4 * Description:
5 * This translation unit implements mutual exclusion (mutex) primitives.
6 *
7 * --------------------------------------------------------------------------
8 *
9 * Pthreads-win32 - POSIX Threads Library for Win32
10 * Copyright(C) 1998 John E. Bossom
11 * Copyright(C) 1999,2005 Pthreads-win32 contributors
12 *
13 * Contact Email: rpj@callisto.canberra.edu.au
14 *
15 * The current list of contributors is contained
16 * in the file CONTRIBUTORS included with the source
17 * code distribution. The list can also be seen at the
18 * following World Wide Web location:
19 * http://sources.redhat.com/pthreads-win32/contributors.html
20 *
21 * This library is free software; you can redistribute it and/or
22 * modify it under the terms of the GNU Lesser General Public
23 * License as published by the Free Software Foundation; either
24 * version 2 of the License, or (at your option) any later version.
25 *
26 * This library is distributed in the hope that it will be useful,
27 * but WITHOUT ANY WARRANTY; without even the implied warranty of
28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
29 * Lesser General Public License for more details.
30 *
31 * You should have received a copy of the GNU Lesser General Public
32 * License along with this library in the file COPYING.LIB;
33 * if not, write to the Free Software Foundation, Inc.,
34 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
35 */
36
37 #if !defined(_UWIN)
38 /*# include <process.h> */
39 #endif
40 #include "pthread.h"
41 #include "implement.h"
42
43 int
pthread_mutex_lock(pthread_mutex_t * mutex)44 pthread_mutex_lock (pthread_mutex_t * mutex)
45 {
46 int kind;
47 pthread_mutex_t mx;
48 int result = 0;
49
50 /*
51 * Let the system deal with invalid pointers.
52 */
53 if (*mutex == NULL)
54 {
55 return EINVAL;
56 }
57
58 /*
59 * We do a quick check to see if we need to do more work
60 * to initialise a static mutex. We check
61 * again inside the guarded section of ptw32_mutex_check_need_init()
62 * to avoid race conditions.
63 */
64 if (*mutex >= PTHREAD_ERRORCHECK_MUTEX_INITIALIZER)
65 {
66 if ((result = ptw32_mutex_check_need_init (mutex)) != 0)
67 {
68 return (result);
69 }
70 }
71
72 mx = *mutex;
73 kind = mx->kind;
74
75 if (kind >= 0)
76 {
77 /* Non-robust */
78 if (PTHREAD_MUTEX_NORMAL == kind)
79 {
80 if ((PTW32_INTERLOCKED_LONG) PTW32_INTERLOCKED_EXCHANGE_LONG(
81 (PTW32_INTERLOCKED_LONGPTR) &mx->lock_idx,
82 (PTW32_INTERLOCKED_LONG) 1) != 0)
83 {
84 while ((PTW32_INTERLOCKED_LONG) PTW32_INTERLOCKED_EXCHANGE_LONG(
85 (PTW32_INTERLOCKED_LONGPTR) &mx->lock_idx,
86 (PTW32_INTERLOCKED_LONG) -1) != 0)
87 {
88 if (WAIT_OBJECT_0 != WaitForSingleObject (mx->event, INFINITE))
89 {
90 result = EINVAL;
91 break;
92 }
93 }
94 }
95 }
96 else
97 {
98 pthread_t self = pthread_self();
99
100 if ((PTW32_INTERLOCKED_LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE_LONG(
101 (PTW32_INTERLOCKED_LONGPTR) &mx->lock_idx,
102 (PTW32_INTERLOCKED_LONG) 1,
103 (PTW32_INTERLOCKED_LONG) 0) == 0)
104 {
105 mx->recursive_count = 1;
106 mx->ownerThread = self;
107 }
108 else
109 {
110 if (pthread_equal (mx->ownerThread, self))
111 {
112 if (kind == PTHREAD_MUTEX_RECURSIVE)
113 {
114 mx->recursive_count++;
115 }
116 else
117 {
118 result = EDEADLK;
119 }
120 }
121 else
122 {
123 while ((PTW32_INTERLOCKED_LONG) PTW32_INTERLOCKED_EXCHANGE_LONG(
124 (PTW32_INTERLOCKED_LONGPTR) &mx->lock_idx,
125 (PTW32_INTERLOCKED_LONG) -1) != 0)
126 {
127 if (WAIT_OBJECT_0 != WaitForSingleObject (mx->event, INFINITE))
128 {
129 result = EINVAL;
130 break;
131 }
132 }
133
134 if (0 == result)
135 {
136 mx->recursive_count = 1;
137 mx->ownerThread = self;
138 }
139 }
140 }
141 }
142 }
143 else
144 {
145 /*
146 * Robust types
147 * All types record the current owner thread.
148 * The mutex is added to a per thread list when ownership is acquired.
149 */
150 ptw32_robust_state_t* statePtr = &mx->robustNode->stateInconsistent;
151
152 if ((PTW32_INTERLOCKED_LONG)PTW32_ROBUST_NOTRECOVERABLE == PTW32_INTERLOCKED_EXCHANGE_ADD_LONG(
153 (PTW32_INTERLOCKED_LONGPTR)statePtr,
154 (PTW32_INTERLOCKED_LONG)0))
155 {
156 result = ENOTRECOVERABLE;
157 }
158 else
159 {
160 pthread_t self = pthread_self();
161
162 kind = -kind - 1; /* Convert to non-robust range */
163
164 if (PTHREAD_MUTEX_NORMAL == kind)
165 {
166 if ((PTW32_INTERLOCKED_LONG) PTW32_INTERLOCKED_EXCHANGE_LONG(
167 (PTW32_INTERLOCKED_LONGPTR) &mx->lock_idx,
168 (PTW32_INTERLOCKED_LONG) 1) != 0)
169 {
170 while (0 == (result = ptw32_robust_mutex_inherit(mutex))
171 && (PTW32_INTERLOCKED_LONG) PTW32_INTERLOCKED_EXCHANGE_LONG(
172 (PTW32_INTERLOCKED_LONGPTR) &mx->lock_idx,
173 (PTW32_INTERLOCKED_LONG) -1) != 0)
174 {
175 if (WAIT_OBJECT_0 != WaitForSingleObject (mx->event, INFINITE))
176 {
177 result = EINVAL;
178 break;
179 }
180 if ((PTW32_INTERLOCKED_LONG)PTW32_ROBUST_NOTRECOVERABLE ==
181 PTW32_INTERLOCKED_EXCHANGE_ADD_LONG(
182 (PTW32_INTERLOCKED_LONGPTR)statePtr,
183 (PTW32_INTERLOCKED_LONG)0))
184 {
185 /* Unblock the next thread */
186 SetEvent(mx->event);
187 result = ENOTRECOVERABLE;
188 break;
189 }
190 }
191 }
192 if (0 == result || EOWNERDEAD == result)
193 {
194 /*
195 * Add mutex to the per-thread robust mutex currently-held list.
196 * If the thread terminates, all mutexes in this list will be unlocked.
197 */
198 ptw32_robust_mutex_add(mutex, self);
199 }
200 }
201 else
202 {
203 if ((PTW32_INTERLOCKED_LONG) PTW32_INTERLOCKED_COMPARE_EXCHANGE_LONG(
204 (PTW32_INTERLOCKED_LONGPTR) &mx->lock_idx,
205 (PTW32_INTERLOCKED_LONG) 1,
206 (PTW32_INTERLOCKED_LONG) 0) == 0)
207 {
208 mx->recursive_count = 1;
209 /*
210 * Add mutex to the per-thread robust mutex currently-held list.
211 * If the thread terminates, all mutexes in this list will be unlocked.
212 */
213 ptw32_robust_mutex_add(mutex, self);
214 }
215 else
216 {
217 if (pthread_equal (mx->ownerThread, self))
218 {
219 if (PTHREAD_MUTEX_RECURSIVE == kind)
220 {
221 mx->recursive_count++;
222 }
223 else
224 {
225 result = EDEADLK;
226 }
227 }
228 else
229 {
230 while (0 == (result = ptw32_robust_mutex_inherit(mutex))
231 && (PTW32_INTERLOCKED_LONG) PTW32_INTERLOCKED_EXCHANGE_LONG(
232 (PTW32_INTERLOCKED_LONGPTR) &mx->lock_idx,
233 (PTW32_INTERLOCKED_LONG) -1) != 0)
234 {
235 if (WAIT_OBJECT_0 != WaitForSingleObject (mx->event, INFINITE))
236 {
237 result = EINVAL;
238 break;
239 }
240 if ((PTW32_INTERLOCKED_LONG)PTW32_ROBUST_NOTRECOVERABLE ==
241 PTW32_INTERLOCKED_EXCHANGE_ADD_LONG(
242 (PTW32_INTERLOCKED_LONGPTR)statePtr,
243 (PTW32_INTERLOCKED_LONG)0))
244 {
245 /* Unblock the next thread */
246 SetEvent(mx->event);
247 result = ENOTRECOVERABLE;
248 break;
249 }
250 }
251
252 if (0 == result || EOWNERDEAD == result)
253 {
254 mx->recursive_count = 1;
255 /*
256 * Add mutex to the per-thread robust mutex currently-held list.
257 * If the thread terminates, all mutexes in this list will be unlocked.
258 */
259 ptw32_robust_mutex_add(mutex, self);
260 }
261 }
262 }
263 }
264 }
265 }
266
267 return (result);
268 }
269
270