Commit | Line | Data |
---|---|---|
fdee2e6d MD |
1 | /* |
2 | * urcu-bp.c | |
3 | * | |
4 | * Userspace RCU library, "bulletproof" version. | |
5 | * | |
6982d6d7 | 6 | * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
fdee2e6d MD |
7 | * Copyright (c) 2009 Paul E. McKenney, IBM Corporation. |
8 | * | |
9 | * This library is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU Lesser General Public | |
11 | * License as published by the Free Software Foundation; either | |
12 | * version 2.1 of the License, or (at your option) any later version. | |
13 | * | |
14 | * This library is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public | |
20 | * License along with this library; if not, write to the Free Software | |
21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
22 | * | |
23 | * IBM's contributions to this file may be relicensed under LGPLv2 or later. | |
24 | */ | |
25 | ||
0617bf4c | 26 | #define _GNU_SOURCE |
71c811bf | 27 | #define _LGPL_SOURCE |
fdee2e6d MD |
28 | #include <stdio.h> |
29 | #include <pthread.h> | |
30 | #include <signal.h> | |
31 | #include <assert.h> | |
32 | #include <stdlib.h> | |
33 | #include <string.h> | |
34 | #include <errno.h> | |
35 | #include <poll.h> | |
36 | #include <unistd.h> | |
37 | #include <sys/mman.h> | |
38 | ||
71c811bf | 39 | #include "urcu/wfqueue.h" |
57760d44 | 40 | #include "urcu/map/urcu-bp.h" |
af7c2dbe | 41 | #include "urcu/static/urcu-bp.h" |
618b2595 | 42 | #include "urcu-pointer.h" |
bd252a04 | 43 | #include "urcu/tls-compat.h" |
71c811bf | 44 | |
4a6d7378 MD |
45 | #include "urcu-die.h" |
46 | ||
fdee2e6d | 47 | /* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */ |
71c811bf | 48 | #undef _LGPL_SOURCE |
fdee2e6d | 49 | #include "urcu-bp.h" |
71c811bf | 50 | #define _LGPL_SOURCE |
fdee2e6d | 51 | |
4c1ae2ea MD |
52 | #ifndef MAP_ANONYMOUS |
53 | #define MAP_ANONYMOUS MAP_ANON | |
54 | #endif | |
55 | ||
c7eaf61c MD |
56 | #ifdef __linux__ |
57 | static | |
58 | void *mremap_wrapper(void *old_address, size_t old_size, | |
59 | size_t new_size, int flags) | |
60 | { | |
61 | return mremap(old_address, old_size, new_size, flags); | |
62 | } | |
63 | #else | |
45a4872f MD |
64 | |
65 | #define MREMAP_MAYMOVE 1 | |
66 | #define MREMAP_FIXED 2 | |
67 | ||
68 | /* | |
89451e1b | 69 | * mremap wrapper for non-Linux systems not allowing MAYMOVE. |
45a4872f MD |
70 | * This is not generic. |
71 | */ | |
c7eaf61c MD |
72 | static |
73 | void *mremap_wrapper(void *old_address, size_t old_size, | |
74 | size_t new_size, int flags) | |
45a4872f | 75 | { |
89451e1b MD |
76 | assert(!(flags & MREMAP_MAYMOVE)); |
77 | ||
78 | return MAP_FAILED; | |
45a4872f MD |
79 | } |
80 | #endif | |
81 | ||
fdee2e6d MD |
82 | /* Sleep delay in us */ |
83 | #define RCU_SLEEP_DELAY 1000 | |
89451e1b MD |
84 | #define INIT_NR_THREADS 8 |
85 | #define ARENA_INIT_ALLOC \ | |
86 | sizeof(struct registry_chunk) \ | |
87 | + INIT_NR_THREADS * sizeof(struct rcu_reader) | |
fdee2e6d | 88 | |
b7b6a8f5 PB |
89 | /* |
90 | * Active attempts to check for reader Q.S. before calling sleep(). | |
91 | */ | |
92 | #define RCU_QS_ACTIVE_ATTEMPTS 100 | |
93 | ||
02be5561 | 94 | void __attribute__((destructor)) rcu_bp_exit(void); |
fdee2e6d | 95 | |
6abb4bd5 | 96 | static pthread_mutex_t rcu_gp_lock = PTHREAD_MUTEX_INITIALIZER; |
fdee2e6d MD |
97 | |
98 | #ifdef DEBUG_YIELD | |
99 | unsigned int yield_active; | |
bd252a04 | 100 | DEFINE_URCU_TLS(unsigned int, rand_yield); |
fdee2e6d MD |
101 | #endif |
102 | ||
103 | /* | |
104 | * Global grace period counter. | |
02be5561 | 105 | * Contains the current RCU_GP_CTR_PHASE. |
fdee2e6d MD |
106 | * Also has a RCU_GP_COUNT of 1, to accelerate the reader fast path. |
107 | * Written to only by writer with mutex taken. Read by both writer and readers. | |
108 | */ | |
02be5561 | 109 | long rcu_gp_ctr = RCU_GP_COUNT; |
fdee2e6d MD |
110 | |
111 | /* | |
112 | * Pointer to registry elements. Written to only by each individual reader. Read | |
113 | * by both the reader and the writers. | |
114 | */ | |
bd252a04 | 115 | DEFINE_URCU_TLS(struct rcu_reader *, rcu_reader); |
fdee2e6d | 116 | |
16aa9ee8 | 117 | static CDS_LIST_HEAD(registry); |
fdee2e6d | 118 | |
89451e1b MD |
119 | struct registry_chunk { |
120 | size_t data_len; /* data length */ | |
121 | size_t used; /* data used */ | |
122 | struct cds_list_head node; /* chunk_list node */ | |
123 | char data[]; | |
124 | }; | |
125 | ||
fdee2e6d | 126 | struct registry_arena { |
89451e1b | 127 | struct cds_list_head chunk_list; |
fdee2e6d MD |
128 | }; |
129 | ||
89451e1b MD |
130 | static struct registry_arena registry_arena = { |
131 | .chunk_list = CDS_LIST_HEAD_INIT(registry_arena.chunk_list), | |
132 | }; | |
fdee2e6d | 133 | |
4cf1675f MD |
134 | /* Saved fork signal mask, protected by rcu_gp_lock */ |
135 | static sigset_t saved_fork_signal_mask; | |
136 | ||
fdee2e6d MD |
137 | static void rcu_gc_registry(void); |
138 | ||
6abb4bd5 | 139 | static void mutex_lock(pthread_mutex_t *mutex) |
fdee2e6d MD |
140 | { |
141 | int ret; | |
142 | ||
143 | #ifndef DISTRUST_SIGNALS_EXTREME | |
6abb4bd5 | 144 | ret = pthread_mutex_lock(mutex); |
4a6d7378 MD |
145 | if (ret) |
146 | urcu_die(ret); | |
fdee2e6d | 147 | #else /* #ifndef DISTRUST_SIGNALS_EXTREME */ |
6abb4bd5 | 148 | while ((ret = pthread_mutex_trylock(mutex)) != 0) { |
4a6d7378 MD |
149 | if (ret != EBUSY && ret != EINTR) |
150 | urcu_die(ret); | |
fdee2e6d MD |
151 | poll(NULL,0,10); |
152 | } | |
153 | #endif /* #else #ifndef DISTRUST_SIGNALS_EXTREME */ | |
154 | } | |
155 | ||
6abb4bd5 | 156 | static void mutex_unlock(pthread_mutex_t *mutex) |
fdee2e6d MD |
157 | { |
158 | int ret; | |
159 | ||
6abb4bd5 | 160 | ret = pthread_mutex_unlock(mutex); |
4a6d7378 MD |
161 | if (ret) |
162 | urcu_die(ret); | |
fdee2e6d MD |
163 | } |
164 | ||
2dfb8b5e | 165 | void update_counter_and_wait(void) |
fdee2e6d | 166 | { |
16aa9ee8 | 167 | CDS_LIST_HEAD(qsreaders); |
fdee2e6d | 168 | int wait_loops = 0; |
02be5561 | 169 | struct rcu_reader *index, *tmp; |
fdee2e6d | 170 | |
32c15e4e | 171 | /* Switch parity: 0 -> 1, 1 -> 0 */ |
6cf3827c | 172 | CMM_STORE_SHARED(rcu_gp_ctr, rcu_gp_ctr ^ RCU_GP_CTR_PHASE); |
2dfb8b5e MD |
173 | |
174 | /* | |
175 | * Must commit qparity update to memory before waiting for other parity | |
176 | * quiescent state. Failure to do so could result in the writer waiting | |
177 | * forever while new readers are always accessing data (no progress). | |
6cf3827c | 178 | * Ensured by CMM_STORE_SHARED and CMM_LOAD_SHARED. |
2dfb8b5e MD |
179 | */ |
180 | ||
181 | /* | |
5481ddb3 | 182 | * Adding a cmm_smp_mb() which is _not_ formally required, but makes the |
2dfb8b5e MD |
183 | * model easier to understand. It does not have a big performance impact |
184 | * anyway, given this is the write-side. | |
185 | */ | |
5481ddb3 | 186 | cmm_smp_mb(); |
2dfb8b5e | 187 | |
fdee2e6d | 188 | /* |
02be5561 | 189 | * Wait for each thread rcu_reader.ctr count to become 0. |
fdee2e6d MD |
190 | */ |
191 | for (;;) { | |
192 | wait_loops++; | |
16aa9ee8 | 193 | cds_list_for_each_entry_safe(index, tmp, ®istry, node) { |
fdee2e6d | 194 | if (!rcu_old_gp_ongoing(&index->ctr)) |
16aa9ee8 | 195 | cds_list_move(&index->node, &qsreaders); |
fdee2e6d MD |
196 | } |
197 | ||
16aa9ee8 | 198 | if (cds_list_empty(®istry)) { |
fdee2e6d MD |
199 | break; |
200 | } else { | |
201 | if (wait_loops == RCU_QS_ACTIVE_ATTEMPTS) | |
202 | usleep(RCU_SLEEP_DELAY); | |
203 | else | |
06f22bdb | 204 | caa_cpu_relax(); |
fdee2e6d MD |
205 | } |
206 | } | |
207 | /* put back the reader list in the registry */ | |
16aa9ee8 | 208 | cds_list_splice(&qsreaders, ®istry); |
fdee2e6d MD |
209 | } |
210 | ||
211 | void synchronize_rcu(void) | |
212 | { | |
213 | sigset_t newmask, oldmask; | |
214 | int ret; | |
215 | ||
264716f7 | 216 | ret = sigfillset(&newmask); |
fdee2e6d | 217 | assert(!ret); |
264716f7 | 218 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); |
fdee2e6d MD |
219 | assert(!ret); |
220 | ||
6abb4bd5 | 221 | mutex_lock(&rcu_gp_lock); |
fdee2e6d | 222 | |
16aa9ee8 | 223 | if (cds_list_empty(®istry)) |
2dfb8b5e | 224 | goto out; |
fdee2e6d MD |
225 | |
226 | /* All threads should read qparity before accessing data structure | |
2dfb8b5e | 227 | * where new ptr points to. */ |
fdee2e6d | 228 | /* Write new ptr before changing the qparity */ |
5481ddb3 | 229 | cmm_smp_mb(); |
fdee2e6d | 230 | |
2dfb8b5e MD |
231 | /* Remove old registry elements */ |
232 | rcu_gc_registry(); | |
fdee2e6d MD |
233 | |
234 | /* | |
235 | * Wait for previous parity to be empty of readers. | |
236 | */ | |
2dfb8b5e | 237 | update_counter_and_wait(); /* 0 -> 1, wait readers in parity 0 */ |
fdee2e6d MD |
238 | |
239 | /* | |
5481ddb3 | 240 | * Adding a cmm_smp_mb() which is _not_ formally required, but makes the |
fdee2e6d MD |
241 | * model easier to understand. It does not have a big performance impact |
242 | * anyway, given this is the write-side. | |
243 | */ | |
5481ddb3 | 244 | cmm_smp_mb(); |
fdee2e6d | 245 | |
fdee2e6d | 246 | /* |
2dfb8b5e | 247 | * Wait for previous parity to be empty of readers. |
fdee2e6d | 248 | */ |
2dfb8b5e | 249 | update_counter_and_wait(); /* 1 -> 0, wait readers in parity 1 */ |
fdee2e6d MD |
250 | |
251 | /* | |
2dfb8b5e MD |
252 | * Finish waiting for reader threads before letting the old ptr being |
253 | * freed. | |
fdee2e6d | 254 | */ |
5481ddb3 | 255 | cmm_smp_mb(); |
2dfb8b5e | 256 | out: |
6abb4bd5 | 257 | mutex_unlock(&rcu_gp_lock); |
fdee2e6d MD |
258 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); |
259 | assert(!ret); | |
260 | } | |
261 | ||
262 | /* | |
263 | * library wrappers to be used by non-LGPL compatible source code. | |
264 | */ | |
265 | ||
266 | void rcu_read_lock(void) | |
267 | { | |
268 | _rcu_read_lock(); | |
269 | } | |
270 | ||
271 | void rcu_read_unlock(void) | |
272 | { | |
273 | _rcu_read_unlock(); | |
274 | } | |
275 | ||
276 | /* | |
89451e1b MD |
277 | * Only grow for now. If empty, allocate a ARENA_INIT_ALLOC sized chunk. |
278 | * Else, try expanding the last chunk. If this fails, allocate a new | |
279 | * chunk twice as big as the last chunk. | |
280 | * Memory used by chunks _never_ moves. A chunk could theoretically be | |
281 | * freed when all "used" slots are released, but we don't do it at this | |
282 | * point. | |
fdee2e6d | 283 | */ |
89451e1b MD |
284 | static |
285 | void expand_arena(struct registry_arena *arena) | |
fdee2e6d | 286 | { |
89451e1b MD |
287 | struct registry_chunk *new_chunk, *last_chunk; |
288 | size_t old_chunk_len, new_chunk_len; | |
289 | ||
290 | /* No chunk. */ | |
291 | if (cds_list_empty(&arena->chunk_list)) { | |
292 | assert(ARENA_INIT_ALLOC >= | |
293 | sizeof(struct registry_chunk) | |
294 | + sizeof(struct rcu_reader)); | |
295 | new_chunk_len = ARENA_INIT_ALLOC; | |
296 | new_chunk = mmap(NULL, new_chunk_len, | |
0bcbf365 MD |
297 | PROT_READ | PROT_WRITE, |
298 | MAP_ANONYMOUS | MAP_PRIVATE, | |
299 | -1, 0); | |
89451e1b MD |
300 | if (new_chunk == MAP_FAILED) |
301 | abort(); | |
302 | bzero(new_chunk, new_chunk_len); | |
303 | new_chunk->data_len = | |
304 | new_chunk_len - sizeof(struct registry_chunk); | |
305 | cds_list_add_tail(&new_chunk->node, &arena->chunk_list); | |
306 | return; /* We're done. */ | |
307 | } | |
0bcbf365 | 308 | |
89451e1b MD |
309 | /* Try expanding last chunk. */ |
310 | last_chunk = cds_list_entry(arena->chunk_list.prev, | |
311 | struct registry_chunk, node); | |
312 | old_chunk_len = | |
313 | last_chunk->data_len + sizeof(struct registry_chunk); | |
314 | new_chunk_len = old_chunk_len << 1; | |
315 | ||
316 | /* Don't allow memory mapping to move, just expand. */ | |
317 | new_chunk = mremap_wrapper(last_chunk, old_chunk_len, | |
318 | new_chunk_len, 0); | |
319 | if (new_chunk != MAP_FAILED) { | |
320 | /* Should not have moved. */ | |
321 | assert(new_chunk == last_chunk); | |
322 | bzero((char *) last_chunk + old_chunk_len, | |
323 | new_chunk_len - old_chunk_len); | |
324 | last_chunk->data_len = | |
325 | new_chunk_len - sizeof(struct registry_chunk); | |
326 | return; /* We're done. */ | |
327 | } | |
0617bf4c | 328 | |
89451e1b MD |
329 | /* Remap did not succeed, we need to add a new chunk. */ |
330 | new_chunk = mmap(NULL, new_chunk_len, | |
331 | PROT_READ | PROT_WRITE, | |
332 | MAP_ANONYMOUS | MAP_PRIVATE, | |
333 | -1, 0); | |
334 | if (new_chunk == MAP_FAILED) | |
335 | abort(); | |
336 | bzero(new_chunk, new_chunk_len); | |
337 | new_chunk->data_len = | |
338 | new_chunk_len - sizeof(struct registry_chunk); | |
339 | cds_list_add_tail(&new_chunk->node, &arena->chunk_list); | |
340 | } | |
341 | ||
342 | static | |
343 | struct rcu_reader *arena_alloc(struct registry_arena *arena) | |
344 | { | |
345 | struct registry_chunk *chunk; | |
346 | struct rcu_reader *rcu_reader_reg; | |
347 | int expand_done = 0; /* Only allow to expand once per alloc */ | |
348 | size_t len = sizeof(struct rcu_reader); | |
fdee2e6d | 349 | |
89451e1b MD |
350 | retry: |
351 | cds_list_for_each_entry(chunk, &arena->chunk_list, node) { | |
352 | if (chunk->data_len - chunk->used < len) | |
353 | continue; | |
354 | /* Find spot */ | |
355 | for (rcu_reader_reg = (struct rcu_reader *) &chunk->data[0]; | |
356 | rcu_reader_reg < (struct rcu_reader *) &chunk->data[chunk->data_len]; | |
357 | rcu_reader_reg++) { | |
358 | if (!rcu_reader_reg->alloc) { | |
359 | rcu_reader_reg->alloc = 1; | |
360 | chunk->used += len; | |
361 | return rcu_reader_reg; | |
362 | } | |
363 | } | |
364 | } | |
365 | ||
366 | if (!expand_done) { | |
367 | expand_arena(arena); | |
368 | expand_done = 1; | |
369 | goto retry; | |
370 | } | |
371 | ||
372 | return NULL; | |
fdee2e6d MD |
373 | } |
374 | ||
375 | /* Called with signals off and mutex locked */ | |
89451e1b MD |
376 | static |
377 | void add_thread(void) | |
fdee2e6d | 378 | { |
02be5561 | 379 | struct rcu_reader *rcu_reader_reg; |
fdee2e6d | 380 | |
89451e1b MD |
381 | rcu_reader_reg = arena_alloc(®istry_arena); |
382 | if (!rcu_reader_reg) | |
383 | abort(); | |
fdee2e6d MD |
384 | |
385 | /* Add to registry */ | |
02be5561 MD |
386 | rcu_reader_reg->tid = pthread_self(); |
387 | assert(rcu_reader_reg->ctr == 0); | |
16aa9ee8 | 388 | cds_list_add(&rcu_reader_reg->node, ®istry); |
89451e1b MD |
389 | /* |
390 | * Reader threads are pointing to the reader registry. This is | |
391 | * why its memory should never be relocated. | |
392 | */ | |
bd252a04 | 393 | URCU_TLS(rcu_reader) = rcu_reader_reg; |
fdee2e6d MD |
394 | } |
395 | ||
396 | /* Called with signals off and mutex locked */ | |
397 | static void rcu_gc_registry(void) | |
398 | { | |
89451e1b | 399 | struct registry_chunk *chunk; |
02be5561 | 400 | struct rcu_reader *rcu_reader_reg; |
fdee2e6d | 401 | |
89451e1b MD |
402 | cds_list_for_each_entry(chunk, ®istry_arena.chunk_list, node) { |
403 | for (rcu_reader_reg = (struct rcu_reader *) &chunk->data[0]; | |
404 | rcu_reader_reg < (struct rcu_reader *) &chunk->data[chunk->data_len]; | |
405 | rcu_reader_reg++) { | |
406 | pthread_t tid; | |
407 | int ret; | |
408 | ||
409 | if (!rcu_reader_reg->alloc) | |
410 | continue; | |
411 | tid = rcu_reader_reg->tid; | |
412 | ret = pthread_kill(tid, 0); | |
413 | assert(ret != EINVAL); | |
414 | if (ret == ESRCH) { | |
415 | cds_list_del(&rcu_reader_reg->node); | |
416 | rcu_reader_reg->ctr = 0; | |
417 | rcu_reader_reg->alloc = 0; | |
418 | chunk->used -= sizeof(struct rcu_reader); | |
419 | } | |
420 | ||
fdee2e6d MD |
421 | } |
422 | } | |
423 | } | |
424 | ||
425 | /* Disable signals, take mutex, add to registry */ | |
426 | void rcu_bp_register(void) | |
427 | { | |
428 | sigset_t newmask, oldmask; | |
429 | int ret; | |
430 | ||
264716f7 | 431 | ret = sigfillset(&newmask); |
fdee2e6d | 432 | assert(!ret); |
264716f7 | 433 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); |
fdee2e6d MD |
434 | assert(!ret); |
435 | ||
436 | /* | |
437 | * Check if a signal concurrently registered our thread since | |
438 | * the check in rcu_read_lock(). */ | |
bd252a04 | 439 | if (URCU_TLS(rcu_reader)) |
fdee2e6d MD |
440 | goto end; |
441 | ||
6abb4bd5 | 442 | mutex_lock(&rcu_gp_lock); |
fdee2e6d | 443 | add_thread(); |
6abb4bd5 | 444 | mutex_unlock(&rcu_gp_lock); |
fdee2e6d MD |
445 | end: |
446 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
447 | assert(!ret); | |
448 | } | |
449 | ||
9380711a | 450 | void rcu_bp_exit(void) |
fdee2e6d | 451 | { |
89451e1b MD |
452 | struct registry_chunk *chunk, *tmp; |
453 | ||
454 | cds_list_for_each_entry_safe(chunk, tmp, | |
455 | ®istry_arena.chunk_list, node) { | |
456 | munmap(chunk, chunk->data_len + sizeof(struct registry_chunk)); | |
457 | } | |
fdee2e6d | 458 | } |
4cf1675f MD |
459 | |
460 | /* | |
461 | * Holding the rcu_gp_lock across fork will make sure we fork() don't race with | |
462 | * a concurrent thread executing with this same lock held. This ensures that the | |
463 | * registry is in a coherent state in the child. | |
464 | */ | |
465 | void rcu_bp_before_fork(void) | |
466 | { | |
467 | sigset_t newmask, oldmask; | |
468 | int ret; | |
469 | ||
264716f7 | 470 | ret = sigfillset(&newmask); |
4cf1675f | 471 | assert(!ret); |
264716f7 | 472 | ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask); |
4cf1675f MD |
473 | assert(!ret); |
474 | mutex_lock(&rcu_gp_lock); | |
475 | saved_fork_signal_mask = oldmask; | |
476 | } | |
477 | ||
478 | void rcu_bp_after_fork_parent(void) | |
479 | { | |
480 | sigset_t oldmask; | |
481 | int ret; | |
482 | ||
483 | oldmask = saved_fork_signal_mask; | |
484 | mutex_unlock(&rcu_gp_lock); | |
485 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
486 | assert(!ret); | |
487 | } | |
488 | ||
489 | void rcu_bp_after_fork_child(void) | |
490 | { | |
491 | sigset_t oldmask; | |
492 | int ret; | |
493 | ||
494 | rcu_gc_registry(); | |
495 | oldmask = saved_fork_signal_mask; | |
496 | mutex_unlock(&rcu_gp_lock); | |
497 | ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL); | |
498 | assert(!ret); | |
499 | } | |
5e77fc1f | 500 | |
9b7981bb MD |
501 | void *rcu_dereference_sym_bp(void *p) |
502 | { | |
503 | return _rcu_dereference(p); | |
504 | } | |
505 | ||
5efd3cd2 MD |
506 | void *rcu_set_pointer_sym_bp(void **p, void *v) |
507 | { | |
508 | cmm_wmb(); | |
424d4ed5 MD |
509 | uatomic_set(p, v); |
510 | return v; | |
5efd3cd2 MD |
511 | } |
512 | ||
513 | void *rcu_xchg_pointer_sym_bp(void **p, void *v) | |
514 | { | |
515 | cmm_wmb(); | |
516 | return uatomic_xchg(p, v); | |
517 | } | |
518 | ||
519 | void *rcu_cmpxchg_pointer_sym_bp(void **p, void *old, void *_new) | |
520 | { | |
521 | cmm_wmb(); | |
522 | return uatomic_cmpxchg(p, old, _new); | |
523 | } | |
524 | ||
5e6b23a6 | 525 | DEFINE_RCU_FLAVOR(rcu_flavor); |
541d828d | 526 | |
5e77fc1f | 527 | #include "urcu-call-rcu-impl.h" |
0376e7b2 | 528 | #include "urcu-defer-impl.h" |