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[glibc.git] / ports / sysdeps / unix / sysv / linux / m68k / nptl / lowlevellock.h
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1 /* Copyright (C) 2010-2014 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
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
16 License along with the GNU C Library. If not, see
17 <http://www.gnu.org/licenses/>. */
18
19 /* Borrowed from ARM's version. */
20
21 #ifndef _LOWLEVELLOCK_H
22 #define _LOWLEVELLOCK_H 1
23
24 #include <time.h>
25 #include <sys/param.h>
26 #include <bits/pthreadtypes.h>
27 #include <atomic.h>
28 #include <kernel-features.h>
29
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_REQEUE_PI 11
42 #define FUTEX_CMP_REQEUE_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(futexp, val, timespec, private) \
84 ({ \
85 INTERNAL_SYSCALL_DECL (__err); \
86 long int __ret; \
87 __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \
88 __lll_private_flag (FUTEX_WAIT, private), \
89 (val), (timespec)); \
90 __ret; \
91 })
92
93 #define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private) \
94 ({ \
95 INTERNAL_SYSCALL_DECL (__err); \
96 long int __ret; \
97 int __op = FUTEX_WAIT_BITSET | clockbit; \
98 __ret = INTERNAL_SYSCALL (futex, __err, 6, (long) (futexp), \
99 __lll_private_flag (__op, private), \
100 (val), (timespec), NULL /* Unused. */, \
101 FUTEX_BITSET_MATCH_ANY); \
102 __ret; \
103 })
104
105 #define lll_futex_wake(futexp, nr, private) \
106 ({ \
107 INTERNAL_SYSCALL_DECL (__err); \
108 long int __ret; \
109 __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \
110 __lll_private_flag (FUTEX_WAKE, private), \
111 (nr), 0); \
112 __ret; \
113 })
114
115 #define lll_robust_dead(futexv, private) \
116 do \
117 { \
118 int *__futexp = &(futexv); \
119 atomic_or (__futexp, FUTEX_OWNER_DIED); \
120 lll_futex_wake (__futexp, 1, private); \
121 } \
122 while (0)
123
124 /* Returns non-zero if error happened, zero if success. */
125 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
126 ({ \
127 INTERNAL_SYSCALL_DECL (__err); \
128 long int __ret; \
129 __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
130 __lll_private_flag (FUTEX_CMP_REQUEUE, private),\
131 (nr_wake), (nr_move), (mutex), (val)); \
132 INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
133 })
134
135 /* Returns non-zero if error happened, zero if success. */
136 #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
137 ({ \
138 INTERNAL_SYSCALL_DECL (__err); \
139 long int __ret; \
140 __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
141 __lll_private_flag (FUTEX_WAKE_OP, private), \
142 (nr_wake), (nr_wake2), (futexp2), \
143 FUTEX_OP_CLEAR_WAKE_IF_GT_ONE); \
144 INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
145 })
146
147 /* Priority Inheritance support. */
148 #define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
149 lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
150
151 #define lll_futex_timed_wait_requeue_pi(futexp, val, timespec, clockbit, \
152 mutex, private) \
153 ({ \
154 INTERNAL_SYSCALL_DECL (__err); \
155 long int __ret; \
156 int __op = FUTEX_WAIT_REQUEUE_PI | clockbit; \
157 \
158 __ret = INTERNAL_SYSCALL (futex, __err, 5, (futexp), \
159 __lll_private_flag (__op, private), \
160 (val), (timespec), mutex); \
161 __ret; \
162 })
163
164 #define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, val, priv) \
165 ({ \
166 INTERNAL_SYSCALL_DECL (__err); \
167 long int __ret; \
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 #define lll_trylock(lock) \
175 atomic_compare_and_exchange_val_acq (&(lock), 1, 0)
176
177 #define lll_cond_trylock(lock) \
178 atomic_compare_and_exchange_val_acq (&(lock), 2, 0)
179
180 #define lll_robust_trylock(lock, id) \
181 atomic_compare_and_exchange_val_acq (&(lock), id, 0)
182
183 extern void __lll_lock_wait_private (int *futex) attribute_hidden;
184 extern void __lll_lock_wait (int *futex, int private) attribute_hidden;
185 extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden;
186
187 #define __lll_lock(futex, private) \
188 ((void) ({ \
189 int *__futex = (futex); \
190 if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, \
191 1, 0), 0)) \
192 { \
193 if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \
194 __lll_lock_wait_private (__futex); \
195 else \
196 __lll_lock_wait (__futex, private); \
197 } \
198 }))
199 #define lll_lock(futex, private) __lll_lock (&(futex), private)
200
201
202 #define __lll_robust_lock(futex, id, private) \
203 ({ \
204 int *__futex = (futex); \
205 int __val = 0; \
206 \
207 if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \
208 0), 0)) \
209 __val = __lll_robust_lock_wait (__futex, private); \
210 __val; \
211 })
212 #define lll_robust_lock(futex, id, private) \
213 __lll_robust_lock (&(futex), id, private)
214
215
216 #define __lll_cond_lock(futex, private) \
217 ((void) ({ \
218 int *__futex = (futex); \
219 if (__builtin_expect (atomic_exchange_acq (__futex, 2), 0)) \
220 __lll_lock_wait (__futex, private); \
221 }))
222 #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private)
223
224
225 #define lll_robust_cond_lock(futex, id, private) \
226 __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private)
227
228
229 extern int __lll_timedlock_wait (int *futex, const struct timespec *,
230 int private) attribute_hidden;
231 extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *,
232 int private) attribute_hidden;
233
234 #define __lll_timedlock(futex, abstime, private) \
235 ({ \
236 int *__futex = (futex); \
237 int __val = 0; \
238 \
239 if (__builtin_expect (atomic_exchange_acq (__futex, 1), 0)) \
240 __val = __lll_timedlock_wait (__futex, abstime, private); \
241 __val; \
242 })
243 #define lll_timedlock(futex, abstime, private) \
244 __lll_timedlock (&(futex), abstime, private)
245
246
247 #define __lll_robust_timedlock(futex, abstime, id, private) \
248 ({ \
249 int *__futex = (futex); \
250 int __val = 0; \
251 \
252 if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \
253 0), 0)) \
254 __val = __lll_robust_timedlock_wait (__futex, abstime, private); \
255 __val; \
256 })
257 #define lll_robust_timedlock(futex, abstime, id, private) \
258 __lll_robust_timedlock (&(futex), abstime, id, private)
259
260
261 #define __lll_unlock(futex, private) \
262 (void) \
263 ({ int *__futex = (futex); \
264 int __oldval = atomic_exchange_rel (__futex, 0); \
265 if (__builtin_expect (__oldval > 1, 0)) \
266 lll_futex_wake (__futex, 1, private); \
267 })
268 #define lll_unlock(futex, private) __lll_unlock(&(futex), private)
269
270
271 #define __lll_robust_unlock(futex, private) \
272 (void) \
273 ({ int *__futex = (futex); \
274 int __oldval = atomic_exchange_rel (__futex, 0); \
275 if (__builtin_expect (__oldval & FUTEX_WAITERS, 0)) \
276 lll_futex_wake (__futex, 1, private); \
277 })
278 #define lll_robust_unlock(futex, private) \
279 __lll_robust_unlock(&(futex), private)
280
281
282 #define lll_islocked(futex) \
283 (futex != 0)
284
285
286 /* Our internal lock implementation is identical to the binary-compatible
287 mutex implementation. */
288
289 /* Initializers for lock. */
290 #define LLL_LOCK_INITIALIZER (0)
291 #define LLL_LOCK_INITIALIZER_LOCKED (1)
292
293 /* The states of a lock are:
294 0 - untaken
295 1 - taken by one user
296 >1 - taken by more users */
297
298 /* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
299 wakeup when the clone terminates. The memory location contains the
300 thread ID while the clone is running and is reset to zero
301 afterwards. */
302 #define lll_wait_tid(tid) \
303 do { \
304 __typeof (tid) __tid; \
305 while ((__tid = (tid)) != 0) \
306 lll_futex_wait (&(tid), __tid, LLL_SHARED); \
307 } while (0)
308
309 extern int __lll_timedwait_tid (int *, const struct timespec *)
310 attribute_hidden;
311
312 #define lll_timedwait_tid(tid, abstime) \
313 ({ \
314 int __res = 0; \
315 if ((tid) != 0) \
316 __res = __lll_timedwait_tid (&(tid), (abstime)); \
317 __res; \
318 })
319
320 #endif /* lowlevellock.h */
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