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Relocate alpha from ports to libc
[glibc.git] / sysdeps / unix / sysv / linux / alpha / nptl / lowlevellock.h
blob361bd342f1595dc887ec7cacf3e7a5cccc30bd4a
1 /* Copyright (C) 2003-2014 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
29 #define __NR_futex 394
30 #define FUTEX_WAIT 0
31 #define FUTEX_WAKE 1
32 #define FUTEX_REQUEUE 3
33 #define FUTEX_CMP_REQUEUE 4
34 #define FUTEX_WAKE_OP 5
35 #define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1)
36 #define FUTEX_LOCK_PI 6
37 #define FUTEX_UNLOCK_PI 7
38 #define FUTEX_TRYLOCK_PI 8
39 #define FUTEX_WAIT_BITSET 9
40 #define FUTEX_WAKE_BITSET 10
41 #define FUTEX_WAIT_REQUEUE_PI 11
42 #define FUTEX_CMP_REQUEUE_PI 12
43 #define FUTEX_PRIVATE_FLAG 128
44 #define FUTEX_CLOCK_REALTIME 256
45
46 #define FUTEX_BITSET_MATCH_ANY 0xffffffff
47
48 /* Values for 'private' parameter of locking macros. Yes, the
49 definition seems to be backwards. But it is not. The bit will be
50 reversed before passing to the system call. */
51 #define LLL_PRIVATE 0
52 #define LLL_SHARED FUTEX_PRIVATE_FLAG
53
54
55 #if !defined NOT_IN_libc || defined IS_IN_rtld
56 /* In libc.so or ld.so all futexes are private. */
57 # ifdef __ASSUME_PRIVATE_FUTEX
58 # define __lll_private_flag(fl, private) \
59 ((fl) | FUTEX_PRIVATE_FLAG)
60 # else
61 # define __lll_private_flag(fl, private) \
62 ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))
63 # endif
64 #else
65 # ifdef __ASSUME_PRIVATE_FUTEX
66 # define __lll_private_flag(fl, private) \
67 (((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
68 # else
69 # define __lll_private_flag(fl, private) \
70 (__builtin_constant_p (private) \
71 ? ((private) == 0 \
72 ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) \
73 : (fl)) \
74 : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG) \
75 & THREAD_GETMEM (THREAD_SELF, header.private_futex))))
76 # endif
77 #endif
78
79
80 #define lll_futex_wait(futexp, val, private) \
81 lll_futex_timed_wait (futexp, val, NULL, private)
82
83 #define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private) \
84 ({ \
85 INTERNAL_SYSCALL_DECL (__err); \
86 long int __ret; \
87 int __op = FUTEX_WAIT_BITSET | clockbit; \
88 \
89 __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
90 __lll_private_flag (__op, private), \
91 (val), (timespec), NULL /* Unused. */, \
92 FUTEX_BITSET_MATCH_ANY); \
93 __ret; \
94 })
95
96 #define lll_futex_timed_wait(futexp, val, timespec, private) \
97 ({ \
98 INTERNAL_SYSCALL_DECL (__err); \
99 long int __ret; \
100 __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \
101 __lll_private_flag (FUTEX_WAIT, private), \
102 (val), (timespec)); \
103 INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret : __ret; \
104 })
105
106 #define lll_futex_wake(futexp, nr, private) \
107 ({ \
108 INTERNAL_SYSCALL_DECL (__err); \
109 long int __ret; \
110 __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \
111 __lll_private_flag (FUTEX_WAKE, private), \
112 (nr), 0); \
113 INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret : __ret; \
114 })
115
116 #define lll_robust_dead(futexv, private) \
117 do \
118 { \
119 int *__futexp = &(futexv); \
120 atomic_or (__futexp, FUTEX_OWNER_DIED); \
121 lll_futex_wake (__futexp, 1, private); \
122 } \
123 while (0)
124
125 /* Returns non-zero if error happened, zero if success. */
126 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
127 ({ \
128 INTERNAL_SYSCALL_DECL (__err); \
129 long int __ret; \
130 __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
131 __lll_private_flag (FUTEX_CMP_REQUEUE, private),\
132 (nr_wake), (nr_move), (mutex), (val)); \
133 INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
134 })
135
136 /* Returns non-zero if error happened, zero if success. */
137 #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
138 ({ \
139 INTERNAL_SYSCALL_DECL (__err); \
140 long int __ret; \
141 __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
142 __lll_private_flag (FUTEX_WAKE_OP, private), \
143 (nr_wake), (nr_wake2), (futexp2), \
144 FUTEX_OP_CLEAR_WAKE_IF_GT_ONE); \
145 INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
146 })
147
148 /* Priority Inheritance support. */
149 #define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
150 lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
151
152 #define lll_futex_timed_wait_requeue_pi(futexp, val, timespec, clockbit, \
153 mutex, private) \
154 ({ \
155 INTERNAL_SYSCALL_DECL (__err); \
156 int __op = FUTEX_WAIT_REQUEUE_PI | clockbit; \
157 \
158 INTERNAL_SYSCALL (futex, __err, 5, (futexp), \
159 __lll_private_flag (__op, private), \
160 (val), (timespec), mutex); \
161 })
162
163 #define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, val, priv) \
164 ({ \
165 INTERNAL_SYSCALL_DECL (__err); \
166 long int __ret; \
167 \
168 __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
169 __lll_private_flag (FUTEX_CMP_REQUEUE_PI, priv),\
170 (nr_wake), (nr_move), (mutex), (val)); \
171 INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
172 })
173
174 static inline int __attribute__((always_inline))
175 __lll_trylock(int *futex)
176 {
177 return atomic_compare_and_exchange_val_acq (futex, 1, 0) != 0;
178 }
179 #define lll_trylock(lock) __lll_trylock (&(lock))
180
181
182 static inline int __attribute__((always_inline))
183 __lll_cond_trylock(int *futex)
184 {
185 return atomic_compare_and_exchange_val_acq (futex, 2, 0) != 0;
186 }
187 #define lll_cond_trylock(lock) __lll_cond_trylock (&(lock))
188
189
190 static inline int __attribute__((always_inline))
191 __lll_robust_trylock(int *futex, int id)
192 {
193 return atomic_compare_and_exchange_val_acq (futex, id, 0) != 0;
194 }
195 #define lll_robust_trylock(lock, id) \
196 __lll_robust_trylock (&(lock), id)
197
198 extern void __lll_lock_wait_private (int *futex) attribute_hidden;
199 extern void __lll_lock_wait (int *futex, int private) attribute_hidden;
200 extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden;
201
202 static inline void __attribute__((always_inline))
203 __lll_lock(int *futex, int private)
204 {
205 if (atomic_compare_and_exchange_bool_acq (futex, 1, 0) != 0)
206 {
207 if (__builtin_constant_p (private) && private == LLL_PRIVATE)
208 __lll_lock_wait_private (futex);
209 else
210 __lll_lock_wait (futex, private);
211 }
212 }
213 #define lll_lock(futex, private) __lll_lock (&(futex), private)
214
215
216 static inline int __attribute__ ((always_inline))
217 __lll_robust_lock (int *futex, int id, int private)
218 {
219 int result = 0;
220 if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0)
221 result = __lll_robust_lock_wait (futex, private);
222 return result;
223 }
224 #define lll_robust_lock(futex, id, private) \
225 __lll_robust_lock (&(futex), id, private)
226
227
228 static inline void __attribute__ ((always_inline))
229 __lll_cond_lock (int *futex, int private)
230 {
231 if (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0)
232 __lll_lock_wait (futex, private);
233 }
234 #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private)
235
236
237 #define lll_robust_cond_lock(futex, id, private) \
238 __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private)
239
240
241 extern int __lll_timedlock_wait (int *futex, const struct timespec *,
242 int private) attribute_hidden;
243 extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *,
244 int private) attribute_hidden;
245
246 static inline int __attribute__ ((always_inline))
247 __lll_timedlock (int *futex, const struct timespec *abstime, int private)
248 {
249 int result = 0;
250 if (atomic_compare_and_exchange_bool_acq (futex, 1, 0) != 0)
251 result = __lll_timedlock_wait (futex, abstime, private);
252 return result;
253 }
254 #define lll_timedlock(futex, abstime, private) \
255 __lll_timedlock (&(futex), abstime, private)
256
257
258 static inline int __attribute__ ((always_inline))
259 __lll_robust_timedlock (int *futex, const struct timespec *abstime,
260 int id, int private)
261 {
262 int result = 0;
263 if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0)
264 result = __lll_robust_timedlock_wait (futex, abstime, private);
265 return result;
266 }
267 #define lll_robust_timedlock(futex, abstime, id, private) \
268 __lll_robust_timedlock (&(futex), abstime, id, private)
269
270
271 #define __lll_unlock(futex, private) \
272 (void) \
273 ({ int *__futex = (futex); \
274 int __oldval = atomic_exchange_rel (__futex, 0); \
275 if (__builtin_expect (__oldval > 1, 0)) \
276 lll_futex_wake (__futex, 1, private); \
277 })
278 #define lll_unlock(futex, private) __lll_unlock(&(futex), private)
279
280
281 #define __lll_robust_unlock(futex, private) \
282 (void) \
283 ({ int *__futex = (futex); \
284 int __oldval = atomic_exchange_rel (__futex, 0); \
285 if (__builtin_expect (__oldval & FUTEX_WAITERS, 0)) \
286 lll_futex_wake (__futex, 1, private); \
287 })
288 #define lll_robust_unlock(futex, private) \
289 __lll_robust_unlock(&(futex), private)
290
291
292 #define lll_islocked(futex) \
293 (futex != 0)
294
295 /* Initializers for lock. */
296 #define LLL_LOCK_INITIALIZER (0)
297 #define LLL_LOCK_INITIALIZER_LOCKED (1)
298
299
300 /* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
301 wakeup when the clone terminates. The memory location contains the
302 thread ID while the clone is running and is reset to zero
303 afterwards. */
304 #define lll_wait_tid(tid) \
305 do { \
306 __typeof (tid) __tid; \
307 while ((__tid = (tid)) != 0) \
308 lll_futex_wait (&(tid), __tid, LLL_SHARED); \
309 } while (0)
310
311 extern int __lll_timedwait_tid (int *, const struct timespec *)
312 attribute_hidden;
313
314 #define lll_timedwait_tid(tid, abstime) \
315 ({ \
316 int __res = 0; \
317 if ((tid) != 0) \
318 __res = __lll_timedwait_tid (&(tid), (abstime)); \
319 __res; \
320 })
321
322 #endif /* lowlevellock.h */
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