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d4697bc9 | 1 | /* Copyright (C) 2003-2014 Free Software Foundation, Inc. |
a88c9263 UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
a88c9263 UD |
18 | |
19 | #ifndef _LOWLEVELLOCK_H | |
20 | #define _LOWLEVELLOCK_H 1 | |
21 | ||
22 | #include <time.h> | |
23 | #include <sys/param.h> | |
24 | #include <bits/pthreadtypes.h> | |
39358e8b | 25 | #include <atomic.h> |
f8de5057 | 26 | #include <kernel-features.h> |
a88c9263 UD |
27 | |
28 | #define SYS_futex 238 | |
29 | #define FUTEX_WAIT 0 | |
30 | #define FUTEX_WAKE 1 | |
284bdc42 | 31 | #define FUTEX_REQUEUE 3 |
75fccede | 32 | #define FUTEX_CMP_REQUEUE 4 |
b9b8cf03 UD |
33 | #define FUTEX_WAKE_OP 5 |
34 | #define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1) | |
d5ba53f9 UD |
35 | #define FUTEX_LOCK_PI 6 |
36 | #define FUTEX_UNLOCK_PI 7 | |
37 | #define FUTEX_TRYLOCK_PI 8 | |
da5ac135 UD |
38 | #define FUTEX_WAIT_BITSET 9 |
39 | #define FUTEX_WAKE_BITSET 10 | |
8313cb99 SP |
40 | #define FUTEX_WAIT_REQUEUE_PI 11 |
41 | #define FUTEX_CMP_REQUEUE_PI 12 | |
085a4412 | 42 | #define FUTEX_PRIVATE_FLAG 128 |
7dd650d7 UD |
43 | #define FUTEX_CLOCK_REALTIME 256 |
44 | ||
45 | #define FUTEX_BITSET_MATCH_ANY 0xffffffff | |
085a4412 UD |
46 | |
47 | /* Values for 'private' parameter of locking macros. Yes, the | |
48 | definition seems to be backwards. But it is not. The bit will be | |
49 | reversed before passing to the system call. */ | |
50 | #define LLL_PRIVATE 0 | |
51 | #define LLL_SHARED FUTEX_PRIVATE_FLAG | |
52 | ||
53 | ||
4f41c682 | 54 | #if IS_IN (libc) || IS_IN (rtld) |
085a4412 UD |
55 | /* In libc.so or ld.so all futexes are private. */ |
56 | # ifdef __ASSUME_PRIVATE_FUTEX | |
57 | # define __lll_private_flag(fl, private) \ | |
58 | ((fl) | FUTEX_PRIVATE_FLAG) | |
59 | # else | |
60 | # define __lll_private_flag(fl, private) \ | |
61 | ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) | |
62 | # endif | |
63 | #else | |
64 | # ifdef __ASSUME_PRIVATE_FUTEX | |
65 | # define __lll_private_flag(fl, private) \ | |
66 | (((fl) | FUTEX_PRIVATE_FLAG) ^ (private)) | |
67 | # else | |
68 | # define __lll_private_flag(fl, private) \ | |
69 | (__builtin_constant_p (private) \ | |
70 | ? ((private) == 0 \ | |
71 | ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) \ | |
72 | : (fl)) \ | |
73 | : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG) \ | |
74 | & THREAD_GETMEM (THREAD_SELF, header.private_futex)))) | |
da5ac135 | 75 | # endif |
085a4412 | 76 | #endif |
a88c9263 | 77 | |
085a4412 UD |
78 | #define lll_futex_wait(futex, val, private) \ |
79 | lll_futex_timed_wait (futex, val, NULL, private) | |
a88c9263 | 80 | |
8ebac778 | 81 | #define lll_futex_timed_wait(futexp, val, timespec, private) \ |
a88c9263 | 82 | ({ \ |
8ebac778 | 83 | INTERNAL_SYSCALL_DECL (__err); \ |
a88c9263 | 84 | \ |
8ebac778 SP |
85 | INTERNAL_SYSCALL (futex, __err, 4, (futexp), \ |
86 | __lll_private_flag (FUTEX_WAIT, private), \ | |
87 | (val), (timespec)); \ | |
a88c9263 UD |
88 | }) |
89 | ||
8f861542 SP |
90 | #define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private) \ |
91 | ({ \ | |
8ebac778 SP |
92 | INTERNAL_SYSCALL_DECL (__err); \ |
93 | int __op = FUTEX_WAIT_BITSET | clockbit; \ | |
8f861542 | 94 | \ |
8ebac778 SP |
95 | INTERNAL_SYSCALL (futex, __err, 6, (futexp), \ |
96 | __lll_private_flag (__op, private), \ | |
97 | (val), (timespec), NULL /* Unused. */, \ | |
98 | FUTEX_BITSET_MATCH_ANY); \ | |
8f861542 SP |
99 | }) |
100 | ||
8ebac778 | 101 | #define lll_futex_wake(futexp, nr, private) \ |
a88c9263 | 102 | ({ \ |
8ebac778 | 103 | INTERNAL_SYSCALL_DECL (__err); \ |
a88c9263 | 104 | \ |
8ebac778 SP |
105 | INTERNAL_SYSCALL (futex, __err, 4, (futexp), \ |
106 | __lll_private_flag (FUTEX_WAKE, private), \ | |
107 | (nr), 0); \ | |
a88c9263 UD |
108 | }) |
109 | ||
f1740bc4 | 110 | |
75fccede | 111 | /* Returns non-zero if error happened, zero if success. */ |
8ebac778 | 112 | #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \ |
284bdc42 | 113 | ({ \ |
8ebac778 SP |
114 | INTERNAL_SYSCALL_DECL (__err); \ |
115 | long int __ret; \ | |
b9b8cf03 | 116 | \ |
8ebac778 SP |
117 | __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \ |
118 | __lll_private_flag (FUTEX_CMP_REQUEUE, private),\ | |
119 | (nr_wake), (nr_move), (mutex), (val)); \ | |
120 | INTERNAL_SYSCALL_ERROR_P (__ret, __err); \ | |
b9b8cf03 UD |
121 | }) |
122 | ||
b9b8cf03 | 123 | /* Returns non-zero if error happened, zero if success. */ |
8ebac778 | 124 | #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \ |
b9b8cf03 | 125 | ({ \ |
8ebac778 SP |
126 | INTERNAL_SYSCALL_DECL (__err); \ |
127 | long int __ret; \ | |
284bdc42 | 128 | \ |
8ebac778 SP |
129 | __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \ |
130 | __lll_private_flag (FUTEX_WAKE_OP, private), \ | |
131 | (nr_wake), (nr_wake2), (futexp2), \ | |
132 | FUTEX_OP_CLEAR_WAKE_IF_GT_ONE); \ | |
133 | INTERNAL_SYSCALL_ERROR_P (__ret, __err); \ | |
284bdc42 UD |
134 | }) |
135 | ||
8313cb99 SP |
136 | /* Priority Inheritance support. */ |
137 | #define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \ | |
138 | lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private) | |
139 | ||
140 | #define lll_futex_timed_wait_requeue_pi(futexp, val, timespec, clockbit, \ | |
141 | mutex, private) \ | |
142 | ({ \ | |
143 | INTERNAL_SYSCALL_DECL (__err); \ | |
144 | int __op = FUTEX_WAIT_REQUEUE_PI | clockbit; \ | |
145 | \ | |
146 | INTERNAL_SYSCALL (futex, __err, 5, (futexp), \ | |
147 | __lll_private_flag (__op, private), \ | |
148 | (val), (timespec), mutex); \ | |
149 | }) | |
150 | ||
151 | #define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, val, priv) \ | |
152 | ({ \ | |
153 | INTERNAL_SYSCALL_DECL (__err); \ | |
154 | long int __ret; \ | |
155 | \ | |
156 | __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \ | |
157 | __lll_private_flag (FUTEX_CMP_REQUEUE_PI, priv),\ | |
158 | (nr_wake), (nr_move), (mutex), (val)); \ | |
159 | INTERNAL_SYSCALL_ERROR_P (__ret, __err); \ | |
160 | }) | |
161 | ||
a88c9263 UD |
162 | #define lll_compare_and_swap(futex, oldval, newval, operation) \ |
163 | do { \ | |
164 | __typeof (futex) __futex = (futex); \ | |
165 | __asm __volatile (" l %1,%0\n" \ | |
166 | "0: " operation "\n" \ | |
167 | " cs %1,%2,%0\n" \ | |
168 | " jl 0b\n" \ | |
169 | "1:" \ | |
170 | : "=Q" (*__futex), "=&d" (oldval), "=&d" (newval) \ | |
f1847a84 | 171 | : "m" (*__futex) : "cc", "memory" ); \ |
a88c9263 UD |
172 | } while (0) |
173 | ||
174 | ||
175 | static inline int | |
176 | __attribute__ ((always_inline)) | |
e51deae7 | 177 | __lll_trylock (int *futex) |
a88c9263 UD |
178 | { |
179 | unsigned int old; | |
180 | ||
181 | __asm __volatile ("cs %0,%3,%1" | |
182 | : "=d" (old), "=Q" (*futex) | |
f1847a84 | 183 | : "0" (0), "d" (1), "m" (*futex) : "cc", "memory" ); |
a88c9263 UD |
184 | return old != 0; |
185 | } | |
e51deae7 | 186 | #define lll_trylock(futex) __lll_trylock (&(futex)) |
a88c9263 UD |
187 | |
188 | ||
2c0b891a UD |
189 | static inline int |
190 | __attribute__ ((always_inline)) | |
e51deae7 | 191 | __lll_cond_trylock (int *futex) |
2c0b891a UD |
192 | { |
193 | unsigned int old; | |
194 | ||
195 | __asm __volatile ("cs %0,%3,%1" | |
196 | : "=d" (old), "=Q" (*futex) | |
f1847a84 | 197 | : "0" (0), "d" (2), "m" (*futex) : "cc", "memory" ); |
2c0b891a UD |
198 | return old != 0; |
199 | } | |
e51deae7 | 200 | #define lll_cond_trylock(futex) __lll_cond_trylock (&(futex)) |
2c0b891a UD |
201 | |
202 | ||
e51deae7 UD |
203 | extern void __lll_lock_wait_private (int *futex) attribute_hidden; |
204 | extern void __lll_lock_wait (int *futex, int private) attribute_hidden; | |
205 | extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden; | |
a88c9263 UD |
206 | |
207 | static inline void | |
208 | __attribute__ ((always_inline)) | |
e51deae7 | 209 | __lll_lock (int *futex, int private) |
a88c9263 | 210 | { |
a1ffb40e | 211 | if (__glibc_unlikely (atomic_compare_and_exchange_bool_acq (futex, 1, 0))) |
e51deae7 UD |
212 | { |
213 | if (__builtin_constant_p (private) && private == LLL_PRIVATE) | |
214 | __lll_lock_wait_private (futex); | |
215 | else | |
216 | __lll_lock_wait (futex, private); | |
217 | } | |
a88c9263 | 218 | } |
e51deae7 | 219 | #define lll_lock(futex, private) __lll_lock (&(futex), private) |
a88c9263 | 220 | |
f1740bc4 UD |
221 | static inline int |
222 | __attribute__ ((always_inline)) | |
e51deae7 | 223 | __lll_robust_lock (int *futex, int id, int private) |
f1740bc4 UD |
224 | { |
225 | int result = 0; | |
e51deae7 UD |
226 | if (__builtin_expect (atomic_compare_and_exchange_bool_acq (futex, id, 0), |
227 | 0)) | |
228 | result = __lll_robust_lock_wait (futex, private); | |
f1740bc4 UD |
229 | return result; |
230 | } | |
e51deae7 UD |
231 | #define lll_robust_lock(futex, id, private) \ |
232 | __lll_robust_lock (&(futex), id, private) | |
f1740bc4 | 233 | |
ef276e64 JJ |
234 | static inline void |
235 | __attribute__ ((always_inline)) | |
e51deae7 | 236 | __lll_cond_lock (int *futex, int private) |
ef276e64 | 237 | { |
a1ffb40e | 238 | if (__glibc_unlikely (atomic_compare_and_exchange_bool_acq (futex, 2, 0))) |
e51deae7 | 239 | __lll_lock_wait (futex, private); |
ef276e64 | 240 | } |
e51deae7 | 241 | #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private) |
ef276e64 | 242 | |
e51deae7 UD |
243 | #define lll_robust_cond_lock(futex, id, private) \ |
244 | __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private) | |
f1740bc4 | 245 | |
39358e8b | 246 | extern int __lll_timedlock_wait |
e51deae7 | 247 | (int *futex, const struct timespec *, int private) attribute_hidden; |
f1740bc4 | 248 | extern int __lll_robust_timedlock_wait |
e51deae7 | 249 | (int *futex, const struct timespec *, int private) attribute_hidden; |
a88c9263 UD |
250 | |
251 | static inline int | |
252 | __attribute__ ((always_inline)) | |
e51deae7 | 253 | __lll_timedlock (int *futex, const struct timespec *abstime, int private) |
a88c9263 | 254 | { |
a88c9263 | 255 | int result = 0; |
a1ffb40e | 256 | if (__glibc_unlikely (atomic_compare_and_exchange_bool_acq (futex, 1, 0))) |
e51deae7 | 257 | result = __lll_timedlock_wait (futex, abstime, private); |
a88c9263 UD |
258 | return result; |
259 | } | |
e51deae7 UD |
260 | #define lll_timedlock(futex, abstime, private) \ |
261 | __lll_timedlock (&(futex), abstime, private) | |
a88c9263 | 262 | |
5a414ff7 DV |
263 | #ifdef ENABLE_LOCK_ELISION |
264 | extern int __lll_timedlock_elision | |
265 | (int *futex, short *adapt_count, const struct timespec *timeout, int private) | |
266 | attribute_hidden; | |
267 | ||
268 | # define lll_timedlock_elision(futex, adapt_count, timeout, private) \ | |
269 | __lll_timedlock_elision(&(futex), &(adapt_count), timeout, private) | |
270 | #endif | |
271 | ||
f1740bc4 UD |
272 | static inline int |
273 | __attribute__ ((always_inline)) | |
e51deae7 UD |
274 | __lll_robust_timedlock (int *futex, const struct timespec *abstime, |
275 | int id, int private) | |
f1740bc4 UD |
276 | { |
277 | int result = 0; | |
e51deae7 UD |
278 | if (__builtin_expect (atomic_compare_and_exchange_bool_acq (futex, id, 0), |
279 | 0)) | |
280 | result = __lll_robust_timedlock_wait (futex, abstime, private); | |
f1740bc4 UD |
281 | return result; |
282 | } | |
e51deae7 UD |
283 | #define lll_robust_timedlock(futex, abstime, id, private) \ |
284 | __lll_robust_timedlock (&(futex), abstime, id, private) | |
f1740bc4 | 285 | |
a88c9263 | 286 | |
702a9414 JJ |
287 | #define __lll_unlock(futex, private) \ |
288 | (void) \ | |
289 | ({ int __oldval; \ | |
290 | int __newval = 0; \ | |
291 | int *__futexp = (futex); \ | |
292 | \ | |
293 | lll_compare_and_swap (__futexp, __oldval, __newval, "slr %2,%2"); \ | |
a1ffb40e | 294 | if (__glibc_unlikely (__oldval > 1)) \ |
702a9414 JJ |
295 | lll_futex_wake (__futexp, 1, private); \ |
296 | }) | |
e51deae7 | 297 | #define lll_unlock(futex, private) __lll_unlock(&(futex), private) |
284bdc42 | 298 | |
b8ba4a27 | 299 | |
702a9414 JJ |
300 | #define __lll_robust_unlock(futex, private) \ |
301 | (void) \ | |
302 | ({ int __oldval; \ | |
303 | int __newval = 0; \ | |
304 | int *__futexp = (futex); \ | |
305 | \ | |
306 | lll_compare_and_swap (__futexp, __oldval, __newval, "slr %2,%2"); \ | |
a1ffb40e | 307 | if (__glibc_unlikely (__oldval & FUTEX_WAITERS)) \ |
702a9414 JJ |
308 | lll_futex_wake (__futexp, 1, private); \ |
309 | }) | |
e51deae7 UD |
310 | #define lll_robust_unlock(futex, private) \ |
311 | __lll_robust_unlock(&(futex), private) | |
a88c9263 | 312 | |
e51deae7 | 313 | #define lll_islocked(futex) \ |
a88c9263 UD |
314 | (futex != 0) |
315 | ||
316 | ||
a88c9263 | 317 | /* Initializers for lock. */ |
39358e8b UD |
318 | #define LLL_LOCK_INITIALIZER (0) |
319 | #define LLL_LOCK_INITIALIZER_LOCKED (1) | |
a88c9263 | 320 | |
adcdc775 | 321 | /* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex |
a88c9263 UD |
322 | wakeup when the clone terminates. The memory location contains the |
323 | thread ID while the clone is running and is reset to zero | |
324 | afterwards. */ | |
702a9414 JJ |
325 | #define __lll_wait_tid(ptid) \ |
326 | do \ | |
327 | { \ | |
328 | int __tid; \ | |
329 | \ | |
330 | while ((__tid = *ptid) != 0) \ | |
331 | lll_futex_wait (ptid, __tid, LLL_SHARED); \ | |
332 | } \ | |
333 | while (0) | |
a88c9263 UD |
334 | #define lll_wait_tid(tid) __lll_wait_tid(&(tid)) |
335 | ||
39358e8b | 336 | extern int __lll_timedwait_tid (int *, const struct timespec *) |
a88c9263 | 337 | attribute_hidden; |
a88c9263 | 338 | |
39358e8b UD |
339 | #define lll_timedwait_tid(tid, abstime) \ |
340 | ({ \ | |
341 | int __res = 0; \ | |
342 | if ((tid) != 0) \ | |
343 | __res = __lll_timedwait_tid (&(tid), (abstime)); \ | |
344 | __res; \ | |
345 | }) | |
a88c9263 | 346 | |
5a414ff7 DV |
347 | #ifdef ENABLE_LOCK_ELISION |
348 | extern int __lll_lock_elision (int *futex, short *adapt_count, int private) | |
349 | attribute_hidden; | |
350 | ||
351 | extern int __lll_unlock_elision(int *futex, int private) | |
352 | attribute_hidden; | |
353 | ||
354 | extern int __lll_trylock_elision(int *futex, short *adapt_count) | |
355 | attribute_hidden; | |
356 | ||
357 | # define lll_lock_elision(futex, adapt_count, private) \ | |
358 | __lll_lock_elision (&(futex), &(adapt_count), private) | |
359 | # define lll_unlock_elision(futex, private) \ | |
360 | __lll_unlock_elision (&(futex), private) | |
361 | # define lll_trylock_elision(futex, adapt_count) \ | |
362 | __lll_trylock_elision(&(futex), &(adapt_count)) | |
363 | #endif | |
364 | ||
a88c9263 | 365 | #endif /* lowlevellock.h */ |