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Force eval for fma implementations
[glibc.git] / sysdeps / unix / sysv / linux / arm / lowlevellock.h
blob3199d0a5d6983d1bd7168295383f73cca004af0e
1 /* Copyright (C) 2005-2014 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library. If not, see
16 <http://www.gnu.org/licenses/>. */
17
18 #ifndef _LOWLEVELLOCK_H
19 #define _LOWLEVELLOCK_H 1
20
21 #include <time.h>
22 #include <sys/param.h>
23 #include <bits/pthreadtypes.h>
24 #include <atomic.h>
25 #include <sysdep.h>
26 #include <kernel-features.h>
27
28 #define FUTEX_WAIT 0
29 #define FUTEX_WAKE 1
30 #define FUTEX_REQUEUE 3
31 #define FUTEX_CMP_REQUEUE 4
32 #define FUTEX_WAKE_OP 5
33 #define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1)
34 #define FUTEX_LOCK_PI 6
35 #define FUTEX_UNLOCK_PI 7
36 #define FUTEX_TRYLOCK_PI 8
37 #define FUTEX_WAIT_BITSET 9
38 #define FUTEX_WAKE_BITSET 10
39 #define FUTEX_WAIT_REQUEUE_PI 11
40 #define FUTEX_CMP_REQUEUE_PI 12
41 #define FUTEX_PRIVATE_FLAG 128
42 #define FUTEX_CLOCK_REALTIME 256
43
44 #define FUTEX_BITSET_MATCH_ANY 0xffffffff
45
46 /* Values for 'private' parameter of locking macros. Yes, the
47 definition seems to be backwards. But it is not. The bit will be
48 reversed before passing to the system call. */
49 #define LLL_PRIVATE 0
50 #define LLL_SHARED FUTEX_PRIVATE_FLAG
51
52
53 #if !defined NOT_IN_libc || defined IS_IN_rtld
54 /* In libc.so or ld.so all futexes are private. */
55 # ifdef __ASSUME_PRIVATE_FUTEX
56 # define __lll_private_flag(fl, private) \
57 ((fl) | FUTEX_PRIVATE_FLAG)
58 # else
59 # define __lll_private_flag(fl, private) \
60 ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))
61 # endif
62 #else
63 # ifdef __ASSUME_PRIVATE_FUTEX
64 # define __lll_private_flag(fl, private) \
65 (((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
66 # else
67 # define __lll_private_flag(fl, private) \
68 (__builtin_constant_p (private) \
69 ? ((private) == 0 \
70 ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) \
71 : (fl)) \
72 : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG) \
73 & THREAD_GETMEM (THREAD_SELF, header.private_futex))))
74 # endif
75 #endif
76
77
78 #define lll_futex_wait(futexp, val, private) \
79 lll_futex_timed_wait(futexp, val, NULL, private)
80
81 #define lll_futex_timed_wait(futexp, val, timespec, private) \
82 ({ \
83 INTERNAL_SYSCALL_DECL (__err); \
84 long int __ret; \
85 __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \
86 __lll_private_flag (FUTEX_WAIT, private), \
87 (val), (timespec)); \
88 __ret; \
89 })
90
91 #define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private) \
92 ({ \
93 INTERNAL_SYSCALL_DECL (__err); \
94 long int __ret; \
95 int __op = FUTEX_WAIT_BITSET | clockbit; \
96 __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
97 __lll_private_flag (__op, private), \
98 (val), (timespec), NULL /* Unused. */, \
99 FUTEX_BITSET_MATCH_ANY); \
100 __ret; \
101 })
102
103 #define lll_futex_wake(futexp, nr, private) \
104 ({ \
105 INTERNAL_SYSCALL_DECL (__err); \
106 long int __ret; \
107 __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \
108 __lll_private_flag (FUTEX_WAKE, private), \
109 (nr), 0); \
110 __ret; \
111 })
112
113 /* Returns non-zero if error happened, zero if success. */
114 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
115 ({ \
116 INTERNAL_SYSCALL_DECL (__err); \
117 long int __ret; \
118 __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
119 __lll_private_flag (FUTEX_CMP_REQUEUE, private),\
120 (nr_wake), (nr_move), (mutex), (val)); \
121 INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
122 })
123
124
125 /* Returns non-zero if error happened, zero if success. */
126 #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
127 ({ \
128 INTERNAL_SYSCALL_DECL (__err); \
129 long int __ret; \
130 __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
131 __lll_private_flag (FUTEX_WAKE_OP, private), \
132 (nr_wake), (nr_wake2), (futexp2), \
133 FUTEX_OP_CLEAR_WAKE_IF_GT_ONE); \
134 INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
135 })
136
137 /* Priority Inheritance support. */
138 #define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
139 lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
140
141 #define lll_futex_timed_wait_requeue_pi(futexp, val, timespec, clockbit, \
142 mutex, private) \
143 ({ \
144 INTERNAL_SYSCALL_DECL (__err); \
145 int __op = FUTEX_WAIT_REQUEUE_PI | clockbit; \
146 \
147 INTERNAL_SYSCALL (futex, __err, 5, (futexp), \
148 __lll_private_flag (__op, private), \
149 (val), (timespec), mutex); \
150 })
151
152 #define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, val, priv) \
153 ({ \
154 INTERNAL_SYSCALL_DECL (__err); \
155 long int __ret; \
156 \
157 __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
158 __lll_private_flag (FUTEX_CMP_REQUEUE_PI, priv),\
159 (nr_wake), (nr_move), (mutex), (val)); \
160 INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
161 })
162
163
164 #define lll_trylock(lock) \
165 atomic_compare_and_exchange_val_acq(&(lock), 1, 0)
166
167 #define lll_cond_trylock(lock) \
168 atomic_compare_and_exchange_val_acq(&(lock), 2, 0)
169
170 extern void __lll_lock_wait_private (int *futex) attribute_hidden;
171 extern void __lll_lock_wait (int *futex, int private) attribute_hidden;
172 extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden;
173
174 #define __lll_lock(futex, private) \
175 ((void) ({ \
176 int *__futex = (futex); \
177 if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, \
178 1, 0), 0)) \
179 { \
180 if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \
181 __lll_lock_wait_private (__futex); \
182 else \
183 __lll_lock_wait (__futex, private); \
184 } \
185 }))
186 #define lll_lock(futex, private) __lll_lock (&(futex), private)
187
188
189 #define __lll_robust_lock(futex, id, private) \
190 ({ \
191 int *__futex = (futex); \
192 int __val = 0; \
193 \
194 if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \
195 0), 0)) \
196 __val = __lll_robust_lock_wait (__futex, private); \
197 __val; \
198 })
199 #define lll_robust_lock(futex, id, private) \
200 __lll_robust_lock (&(futex), id, private)
201
202
203 #define __lll_cond_lock(futex, private) \
204 ((void) ({ \
205 int *__futex = (futex); \
206 if (__builtin_expect (atomic_exchange_acq (__futex, 2), 0)) \
207 __lll_lock_wait (__futex, private); \
208 }))
209 #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private)
210
211
212 #define lll_robust_cond_lock(futex, id, private) \
213 __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private)
214
215
216 extern int __lll_timedlock_wait (int *futex, const struct timespec *,
217 int private) attribute_hidden;
218 extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *,
219 int private) attribute_hidden;
220
221 #define __lll_timedlock(futex, abstime, private) \
222 ({ \
223 int *__futex = (futex); \
224 int __val = 0; \
225 \
226 if (__builtin_expect (atomic_exchange_acq (__futex, 1), 0)) \
227 __val = __lll_timedlock_wait (__futex, abstime, private); \
228 __val; \
229 })
230 #define lll_timedlock(futex, abstime, private) \
231 __lll_timedlock (&(futex), abstime, private)
232
233
234 #define __lll_robust_timedlock(futex, abstime, id, private) \
235 ({ \
236 int *__futex = (futex); \
237 int __val = 0; \
238 \
239 if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \
240 0), 0)) \
241 __val = __lll_robust_timedlock_wait (__futex, abstime, private); \
242 __val; \
243 })
244 #define lll_robust_timedlock(futex, abstime, id, private) \
245 __lll_robust_timedlock (&(futex), abstime, id, private)
246
247
248 #define __lll_unlock(futex, private) \
249 (void) \
250 ({ int *__futex = (futex); \
251 int __oldval = atomic_exchange_rel (__futex, 0); \
252 if (__builtin_expect (__oldval > 1, 0)) \
253 lll_futex_wake (__futex, 1, private); \
254 })
255 #define lll_unlock(futex, private) __lll_unlock(&(futex), private)
256
257
258 #define __lll_robust_unlock(futex, private) \
259 (void) \
260 ({ int *__futex = (futex); \
261 int __oldval = atomic_exchange_rel (__futex, 0); \
262 if (__builtin_expect (__oldval & FUTEX_WAITERS, 0)) \
263 lll_futex_wake (__futex, 1, private); \
264 })
265 #define lll_robust_unlock(futex, private) \
266 __lll_robust_unlock(&(futex), private)
267
268
269 #define lll_islocked(futex) \
270 (futex != 0)
271
272
273 /* Our internal lock implementation is identical to the binary-compatible
274 mutex implementation. */
275
276 /* Initializers for lock. */
277 #define LLL_LOCK_INITIALIZER (0)
278 #define LLL_LOCK_INITIALIZER_LOCKED (1)
279
280 /* The states of a lock are:
281 0 - untaken
282 1 - taken by one user
283 >1 - taken by more users */
284
285 /* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
286 wakeup when the clone terminates. The memory location contains the
287 thread ID while the clone is running and is reset to zero
288 afterwards. */
289 #define lll_wait_tid(tid) \
290 do { \
291 __typeof (tid) __tid; \
292 while ((__tid = (tid)) != 0) \
293 lll_futex_wait (&(tid), __tid, LLL_SHARED);\
294 } while (0)
295
296 extern int __lll_timedwait_tid (int *, const struct timespec *)
297 attribute_hidden;
298
299 #define lll_timedwait_tid(tid, abstime) \
300 ({ \
301 int __res = 0; \
302 if ((tid) != 0) \
303 __res = __lll_timedwait_tid (&(tid), (abstime)); \
304 __res; \
305 })
306
307 #endif /* lowlevellock.h */
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