Commit | Line | Data |
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acdb82a2 MJ |
1 | // SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
2 | // SPDX-FileCopyrightText: 2009 Paul E. McKenney, IBM Corporation. | |
3 | // | |
4 | // SPDX-License-Identifier: LGPL-2.1-or-later | |
5 | ||
9f1621ca | 6 | /* |
7ac06cef | 7 | * Userspace RCU QSBR library |
9f1621ca | 8 | * |
9f1621ca MD |
9 | * IBM's contributions to this file may be relicensed under LGPLv2 or later. |
10 | */ | |
11 | ||
e37faee1 | 12 | #define URCU_NO_COMPAT_IDENTIFIERS |
71c811bf | 13 | #define _LGPL_SOURCE |
9f1621ca MD |
14 | #include <stdio.h> |
15 | #include <pthread.h> | |
16 | #include <signal.h> | |
9f1621ca | 17 | #include <stdlib.h> |
6d841bc2 | 18 | #include <stdint.h> |
9f1621ca MD |
19 | #include <string.h> |
20 | #include <errno.h> | |
21 | #include <poll.h> | |
22 | ||
601922a8 | 23 | #include <urcu/annotate.h> |
01477510 | 24 | #include <urcu/assert.h> |
4477a870 MD |
25 | #include <urcu/wfcqueue.h> |
26 | #include <urcu/map/urcu-qsbr.h> | |
727f819d | 27 | #define BUILD_QSBR_LIB |
4477a870 MD |
28 | #include <urcu/static/urcu-qsbr.h> |
29 | #include <urcu/pointer.h> | |
30 | #include <urcu/tls-compat.h> | |
71c811bf | 31 | |
4a6d7378 | 32 | #include "urcu-die.h" |
cba82d7b | 33 | #include "urcu-wait.h" |
ce28e67a | 34 | #include "urcu-utils.h" |
4a6d7378 | 35 | |
4477a870 | 36 | #define URCU_API_MAP |
9f1621ca | 37 | /* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */ |
71c811bf | 38 | #undef _LGPL_SOURCE |
4477a870 | 39 | #include <urcu/urcu-qsbr.h> |
71c811bf | 40 | #define _LGPL_SOURCE |
9f1621ca | 41 | |
4477a870 | 42 | void __attribute__((destructor)) urcu_qsbr_exit(void); |
90f72b8c | 43 | static void urcu_call_rcu_exit(void); |
f6d18c64 | 44 | |
731ccb96 MD |
45 | /* |
46 | * rcu_gp_lock ensures mutual exclusion between threads calling | |
47 | * synchronize_rcu(). | |
48 | */ | |
6abb4bd5 | 49 | static pthread_mutex_t rcu_gp_lock = PTHREAD_MUTEX_INITIALIZER; |
731ccb96 MD |
50 | /* |
51 | * rcu_registry_lock ensures mutual exclusion between threads | |
52 | * registering and unregistering themselves to/from the registry, and | |
53 | * with threads reading that registry from synchronize_rcu(). However, | |
54 | * this lock is not held all the way through the completion of awaiting | |
55 | * for the grace period. It is sporadically released between iterations | |
56 | * on the registry. | |
57 | * rcu_registry_lock may nest inside rcu_gp_lock. | |
58 | */ | |
59 | static pthread_mutex_t rcu_registry_lock = PTHREAD_MUTEX_INITIALIZER; | |
4477a870 | 60 | struct urcu_gp urcu_qsbr_gp = { .ctr = URCU_QSBR_GP_ONLINE }; |
9f1621ca | 61 | |
408f6d92 PB |
62 | /* |
63 | * Active attempts to check for reader Q.S. before calling futex(). | |
64 | */ | |
65 | #define RCU_QS_ACTIVE_ATTEMPTS 100 | |
66 | ||
9f1621ca MD |
67 | /* |
68 | * Written to only by each individual reader. Read by both the reader and the | |
69 | * writers. | |
70 | */ | |
4477a870 | 71 | DEFINE_URCU_TLS(struct urcu_qsbr_reader, urcu_qsbr_reader); |
9f1621ca | 72 | |
16aa9ee8 | 73 | static CDS_LIST_HEAD(registry); |
9f1621ca | 74 | |
6362f68f | 75 | /* |
bf6822a6 | 76 | * Queue keeping threads awaiting to wait for a grace period. Contains |
6362f68f MD |
77 | * struct gp_waiters_thread objects. |
78 | */ | |
bf6822a6 | 79 | static DEFINE_URCU_WAIT_QUEUE(gp_waiters); |
6362f68f | 80 | |
6abb4bd5 | 81 | static void mutex_lock(pthread_mutex_t *mutex) |
9f1621ca MD |
82 | { |
83 | int ret; | |
84 | ||
85 | #ifndef DISTRUST_SIGNALS_EXTREME | |
6abb4bd5 | 86 | ret = pthread_mutex_lock(mutex); |
4a6d7378 MD |
87 | if (ret) |
88 | urcu_die(ret); | |
9f1621ca | 89 | #else /* #ifndef DISTRUST_SIGNALS_EXTREME */ |
6abb4bd5 | 90 | while ((ret = pthread_mutex_trylock(mutex)) != 0) { |
4a6d7378 MD |
91 | if (ret != EBUSY && ret != EINTR) |
92 | urcu_die(ret); | |
9f1621ca MD |
93 | poll(NULL,0,10); |
94 | } | |
95 | #endif /* #else #ifndef DISTRUST_SIGNALS_EXTREME */ | |
96 | } | |
97 | ||
6abb4bd5 | 98 | static void mutex_unlock(pthread_mutex_t *mutex) |
9f1621ca MD |
99 | { |
100 | int ret; | |
101 | ||
6abb4bd5 | 102 | ret = pthread_mutex_unlock(mutex); |
4a6d7378 MD |
103 | if (ret) |
104 | urcu_die(ret); | |
9f1621ca MD |
105 | } |
106 | ||
bc6c15bb MD |
107 | /* |
108 | * synchronize_rcu() waiting. Single thread. | |
109 | */ | |
4d703340 | 110 | static void wait_gp(void) |
bc6c15bb | 111 | { |
4d703340 | 112 | /* Read reader_gp before read futex */ |
5481ddb3 | 113 | cmm_smp_rmb(); |
4974ad5f MD |
114 | while (uatomic_read(&urcu_qsbr_gp.futex) == -1) { |
115 | if (!futex_noasync(&urcu_qsbr_gp.futex, FUTEX_WAIT, -1, NULL, NULL, 0)) { | |
116 | /* | |
117 | * Prior queued wakeups queued by unrelated code | |
118 | * using the same address can cause futex wait to | |
119 | * return 0 even through the futex value is still | |
120 | * -1 (spurious wakeups). Check the value again | |
121 | * in user-space to validate whether it really | |
122 | * differs from -1. | |
123 | */ | |
124 | continue; | |
125 | } | |
b0a841b4 | 126 | switch (errno) { |
4974ad5f | 127 | case EAGAIN: |
b0a841b4 MD |
128 | /* Value already changed. */ |
129 | return; | |
130 | case EINTR: | |
131 | /* Retry if interrupted by signal. */ | |
4974ad5f | 132 | break; /* Get out of switch. Check again. */ |
b0a841b4 MD |
133 | default: |
134 | /* Unexpected error. */ | |
135 | urcu_die(errno); | |
136 | } | |
137 | } | |
bc6c15bb MD |
138 | } |
139 | ||
731ccb96 MD |
140 | /* |
141 | * Always called with rcu_registry lock held. Releases this lock between | |
142 | * iterations and grabs it again. Holds the lock when it returns. | |
143 | */ | |
708d89f0 MD |
144 | static void wait_for_readers(struct cds_list_head *input_readers, |
145 | struct cds_list_head *cur_snap_readers, | |
601922a8 OD |
146 | struct cds_list_head *qsreaders, |
147 | cmm_annotate_t *group) | |
9f1621ca | 148 | { |
9340c38d | 149 | unsigned int wait_loops = 0; |
4477a870 | 150 | struct urcu_qsbr_reader *index, *tmp; |
9f1621ca | 151 | |
9f1621ca | 152 | /* |
4477a870 | 153 | * Wait for each thread URCU_TLS(urcu_qsbr_reader).ctr to either |
f6b42f9c | 154 | * indicate quiescence (offline), or for them to observe the |
4477a870 | 155 | * current urcu_qsbr_gp.ctr value. |
9f1621ca | 156 | */ |
4d703340 | 157 | for (;;) { |
5e81fed7 MD |
158 | if (wait_loops < RCU_QS_ACTIVE_ATTEMPTS) |
159 | wait_loops++; | |
83a2c421 | 160 | if (wait_loops >= RCU_QS_ACTIVE_ATTEMPTS) { |
4477a870 | 161 | uatomic_set(&urcu_qsbr_gp.futex, -1); |
83a2c421 PB |
162 | /* |
163 | * Write futex before write waiting (the other side | |
164 | * reads them in the opposite order). | |
165 | */ | |
166 | cmm_smp_wmb(); | |
708d89f0 | 167 | cds_list_for_each_entry(index, input_readers, node) { |
83a2c421 PB |
168 | _CMM_STORE_SHARED(index->waiting, 1); |
169 | } | |
4d703340 | 170 | /* Write futex before read reader_gp */ |
5481ddb3 | 171 | cmm_smp_mb(); |
4d703340 | 172 | } |
708d89f0 | 173 | cds_list_for_each_entry_safe(index, tmp, input_readers, node) { |
601922a8 | 174 | switch (urcu_qsbr_reader_state(&index->ctr, group)) { |
4477a870 | 175 | case URCU_READER_ACTIVE_CURRENT: |
708d89f0 MD |
176 | if (cur_snap_readers) { |
177 | cds_list_move(&index->node, | |
178 | cur_snap_readers); | |
179 | break; | |
180 | } | |
181 | /* Fall-through */ | |
4477a870 | 182 | case URCU_READER_INACTIVE: |
708d89f0 MD |
183 | cds_list_move(&index->node, qsreaders); |
184 | break; | |
4477a870 | 185 | case URCU_READER_ACTIVE_OLD: |
708d89f0 MD |
186 | /* |
187 | * Old snapshot. Leaving node in | |
188 | * input_readers will make us busy-loop | |
189 | * until the snapshot becomes current or | |
190 | * the reader becomes inactive. | |
191 | */ | |
192 | break; | |
193 | } | |
4d703340 | 194 | } |
bc6c15bb | 195 | |
708d89f0 | 196 | if (cds_list_empty(input_readers)) { |
83a2c421 | 197 | if (wait_loops >= RCU_QS_ACTIVE_ATTEMPTS) { |
4d703340 | 198 | /* Read reader_gp before write futex */ |
601922a8 | 199 | uatomic_store(&urcu_qsbr_gp.futex, 0, CMM_RELEASE); |
4d703340 MD |
200 | } |
201 | break; | |
202 | } else { | |
731ccb96 MD |
203 | /* Temporarily unlock the registry lock. */ |
204 | mutex_unlock(&rcu_registry_lock); | |
83a2c421 | 205 | if (wait_loops >= RCU_QS_ACTIVE_ATTEMPTS) { |
4d703340 | 206 | wait_gp(); |
bc6c15bb | 207 | } else { |
9f1621ca | 208 | #ifndef HAS_INCOHERENT_CACHES |
06f22bdb | 209 | caa_cpu_relax(); |
9f1621ca | 210 | #else /* #ifndef HAS_INCOHERENT_CACHES */ |
5481ddb3 | 211 | cmm_smp_mb(); |
9f1621ca | 212 | #endif /* #else #ifndef HAS_INCOHERENT_CACHES */ |
bc6c15bb | 213 | } |
731ccb96 MD |
214 | /* Re-lock the registry lock before the next loop. */ |
215 | mutex_lock(&rcu_registry_lock); | |
bc6c15bb | 216 | } |
9f1621ca MD |
217 | } |
218 | } | |
219 | ||
47d2f29e MD |
220 | /* |
221 | * Using a two-subphases algorithm for architectures with smaller than 64-bit | |
222 | * long-size to ensure we do not encounter an overflow bug. | |
223 | */ | |
224 | ||
b39e1761 | 225 | #if (CAA_BITS_PER_LONG < 64) |
4477a870 | 226 | void urcu_qsbr_synchronize_rcu(void) |
47d2f29e | 227 | { |
601922a8 OD |
228 | cmm_annotate_define(acquire_group); |
229 | cmm_annotate_define(release_group); | |
708d89f0 MD |
230 | CDS_LIST_HEAD(cur_snap_readers); |
231 | CDS_LIST_HEAD(qsreaders); | |
bc49c323 | 232 | unsigned long was_online; |
bf6822a6 MD |
233 | DEFINE_URCU_WAIT_NODE(wait, URCU_WAIT_WAITING); |
234 | struct urcu_waiters waiters; | |
bc49c323 | 235 | |
4477a870 | 236 | was_online = urcu_qsbr_read_ongoing(); |
bc49c323 | 237 | |
47d2f29e | 238 | /* All threads should read qparity before accessing data structure |
27b940e7 PB |
239 | * where new ptr points to. In the "then" case, rcu_thread_offline |
240 | * includes a memory barrier. | |
241 | * | |
bc49c323 | 242 | * Mark the writer thread offline to make sure we don't wait for |
5e77fc1f PM |
243 | * our own quiescent state. This allows using synchronize_rcu() |
244 | * in threads registered as readers. | |
bc49c323 | 245 | */ |
27b940e7 | 246 | if (was_online) |
4477a870 | 247 | urcu_qsbr_thread_offline(); |
27b940e7 PB |
248 | else |
249 | cmm_smp_mb(); | |
601922a8 | 250 | cmm_annotate_group_mb_release(&release_group); |
bc49c323 | 251 | |
6362f68f | 252 | /* |
bf6822a6 | 253 | * Add ourself to gp_waiters queue of threads awaiting to wait |
6362f68f | 254 | * for a grace period. Proceed to perform the grace period only |
bf6822a6 | 255 | * if we are the first thread added into the queue. |
6362f68f | 256 | */ |
bf6822a6 MD |
257 | if (urcu_wait_add(&gp_waiters, &wait) != 0) { |
258 | /* Not first in queue: will be awakened by another thread. */ | |
259 | urcu_adaptative_busy_wait(&wait); | |
6362f68f MD |
260 | goto gp_end; |
261 | } | |
bf6822a6 MD |
262 | /* We won't need to wake ourself up */ |
263 | urcu_wait_set_state(&wait, URCU_WAIT_RUNNING); | |
6362f68f | 264 | |
6abb4bd5 | 265 | mutex_lock(&rcu_gp_lock); |
47d2f29e | 266 | |
6362f68f | 267 | /* |
bf6822a6 | 268 | * Move all waiters into our local queue. |
6362f68f | 269 | */ |
bf6822a6 | 270 | urcu_move_waiters(&waiters, &gp_waiters); |
6362f68f | 271 | |
731ccb96 MD |
272 | mutex_lock(&rcu_registry_lock); |
273 | ||
16aa9ee8 | 274 | if (cds_list_empty(®istry)) |
2dfb8b5e | 275 | goto out; |
47d2f29e MD |
276 | |
277 | /* | |
f6b42f9c | 278 | * Wait for readers to observe original parity or be quiescent. |
731ccb96 | 279 | * wait_for_readers() can release and grab again rcu_registry_lock |
f99c6e92 | 280 | * internally. |
47d2f29e | 281 | */ |
601922a8 | 282 | wait_for_readers(®istry, &cur_snap_readers, &qsreaders, &acquire_group); |
47d2f29e MD |
283 | |
284 | /* | |
f6b42f9c | 285 | * Must finish waiting for quiescent state for original parity |
4477a870 | 286 | * before committing next urcu_qsbr_gp.ctr update to memory. Failure |
f6b42f9c | 287 | * to do so could result in the writer waiting forever while new |
5e77fc1f | 288 | * readers are always accessing data (no progress). Enforce |
4477a870 MD |
289 | * compiler-order of load URCU_TLS(urcu_qsbr_reader).ctr before store |
290 | * to urcu_qsbr_gp.ctr. | |
47d2f29e | 291 | */ |
5481ddb3 | 292 | cmm_barrier(); |
47d2f29e | 293 | |
47d2f29e | 294 | /* |
5481ddb3 | 295 | * Adding a cmm_smp_mb() which is _not_ formally required, but makes the |
2dfb8b5e MD |
296 | * model easier to understand. It does not have a big performance impact |
297 | * anyway, given this is the write-side. | |
47d2f29e | 298 | */ |
5481ddb3 | 299 | cmm_smp_mb(); |
47d2f29e | 300 | |
f6b42f9c | 301 | /* Switch parity: 0 -> 1, 1 -> 0 */ |
601922a8 OD |
302 | cmm_annotate_group_mem_release(&release_group, &urcu_qsbr_gp.ctr); |
303 | uatomic_store(&urcu_qsbr_gp.ctr, urcu_qsbr_gp.ctr ^ URCU_QSBR_GP_CTR, CMM_RELAXED); | |
f6b42f9c | 304 | |
47d2f29e | 305 | /* |
4477a870 | 306 | * Must commit urcu_qsbr_gp.ctr update to memory before waiting for |
f6b42f9c MD |
307 | * quiescent state. Failure to do so could result in the writer |
308 | * waiting forever while new readers are always accessing data | |
4477a870 MD |
309 | * (no progress). Enforce compiler-order of store to urcu_qsbr_gp.ctr |
310 | * before load URCU_TLS(urcu_qsbr_reader).ctr. | |
47d2f29e | 311 | */ |
f6b42f9c MD |
312 | cmm_barrier(); |
313 | ||
314 | /* | |
315 | * Adding a cmm_smp_mb() which is _not_ formally required, but makes the | |
316 | * model easier to understand. It does not have a big performance impact | |
317 | * anyway, given this is the write-side. | |
318 | */ | |
319 | cmm_smp_mb(); | |
320 | ||
321 | /* | |
322 | * Wait for readers to observe new parity or be quiescent. | |
731ccb96 | 323 | * wait_for_readers() can release and grab again rcu_registry_lock |
f99c6e92 | 324 | * internally. |
f6b42f9c | 325 | */ |
601922a8 | 326 | wait_for_readers(&cur_snap_readers, NULL, &qsreaders, &acquire_group); |
708d89f0 MD |
327 | |
328 | /* | |
329 | * Put quiescent reader list back into registry. | |
330 | */ | |
331 | cds_list_splice(&qsreaders, ®istry); | |
2dfb8b5e | 332 | out: |
731ccb96 | 333 | mutex_unlock(&rcu_registry_lock); |
6abb4bd5 | 334 | mutex_unlock(&rcu_gp_lock); |
bf6822a6 | 335 | urcu_wake_all_waiters(&waiters); |
6362f68f | 336 | gp_end: |
bc49c323 MD |
337 | /* |
338 | * Finish waiting for reader threads before letting the old ptr being | |
47d2f29e MD |
339 | * freed. |
340 | */ | |
601922a8 OD |
341 | cmm_annotate_group_mb_acquire(&acquire_group); |
342 | ||
bc49c323 | 343 | if (was_online) |
4477a870 | 344 | urcu_qsbr_thread_online(); |
27b940e7 PB |
345 | else |
346 | cmm_smp_mb(); | |
47d2f29e | 347 | } |
b39e1761 | 348 | #else /* !(CAA_BITS_PER_LONG < 64) */ |
4477a870 | 349 | void urcu_qsbr_synchronize_rcu(void) |
9f1621ca | 350 | { |
601922a8 OD |
351 | cmm_annotate_define(acquire_group); |
352 | cmm_annotate_define(release_group); | |
708d89f0 | 353 | CDS_LIST_HEAD(qsreaders); |
f0f7dbdd | 354 | unsigned long was_online; |
bf6822a6 MD |
355 | DEFINE_URCU_WAIT_NODE(wait, URCU_WAIT_WAITING); |
356 | struct urcu_waiters waiters; | |
ff2f67a0 | 357 | |
4477a870 | 358 | was_online = urcu_qsbr_read_ongoing(); |
ff2f67a0 MD |
359 | |
360 | /* | |
361 | * Mark the writer thread offline to make sure we don't wait for | |
5e77fc1f PM |
362 | * our own quiescent state. This allows using synchronize_rcu() |
363 | * in threads registered as readers. | |
ff2f67a0 | 364 | */ |
27b940e7 | 365 | if (was_online) |
4477a870 | 366 | urcu_qsbr_thread_offline(); |
27b940e7 PB |
367 | else |
368 | cmm_smp_mb(); | |
601922a8 | 369 | cmm_annotate_group_mb_release(&release_group); |
ff2f67a0 | 370 | |
6362f68f | 371 | /* |
bf6822a6 | 372 | * Add ourself to gp_waiters queue of threads awaiting to wait |
6362f68f | 373 | * for a grace period. Proceed to perform the grace period only |
bf6822a6 | 374 | * if we are the first thread added into the queue. |
6362f68f | 375 | */ |
bf6822a6 MD |
376 | if (urcu_wait_add(&gp_waiters, &wait) != 0) { |
377 | /* Not first in queue: will be awakened by another thread. */ | |
378 | urcu_adaptative_busy_wait(&wait); | |
6362f68f MD |
379 | goto gp_end; |
380 | } | |
bf6822a6 MD |
381 | /* We won't need to wake ourself up */ |
382 | urcu_wait_set_state(&wait, URCU_WAIT_RUNNING); | |
6362f68f | 383 | |
6abb4bd5 | 384 | mutex_lock(&rcu_gp_lock); |
6362f68f MD |
385 | |
386 | /* | |
bf6822a6 | 387 | * Move all waiters into our local queue. |
6362f68f | 388 | */ |
bf6822a6 | 389 | urcu_move_waiters(&waiters, &gp_waiters); |
6362f68f | 390 | |
731ccb96 MD |
391 | mutex_lock(&rcu_registry_lock); |
392 | ||
16aa9ee8 | 393 | if (cds_list_empty(®istry)) |
2dfb8b5e | 394 | goto out; |
f6b42f9c MD |
395 | |
396 | /* Increment current G.P. */ | |
601922a8 OD |
397 | cmm_annotate_group_mem_release(&release_group, &urcu_qsbr_gp.ctr); |
398 | uatomic_store(&urcu_qsbr_gp.ctr, urcu_qsbr_gp.ctr + URCU_QSBR_GP_CTR, CMM_RELAXED); | |
f6b42f9c MD |
399 | |
400 | /* | |
4477a870 | 401 | * Must commit urcu_qsbr_gp.ctr update to memory before waiting for |
f6b42f9c MD |
402 | * quiescent state. Failure to do so could result in the writer |
403 | * waiting forever while new readers are always accessing data | |
4477a870 MD |
404 | * (no progress). Enforce compiler-order of store to urcu_qsbr_gp.ctr |
405 | * before load URCU_TLS(urcu_qsbr_reader).ctr. | |
f6b42f9c MD |
406 | */ |
407 | cmm_barrier(); | |
408 | ||
409 | /* | |
410 | * Adding a cmm_smp_mb() which is _not_ formally required, but makes the | |
411 | * model easier to understand. It does not have a big performance impact | |
412 | * anyway, given this is the write-side. | |
413 | */ | |
414 | cmm_smp_mb(); | |
415 | ||
416 | /* | |
417 | * Wait for readers to observe new count of be quiescent. | |
731ccb96 | 418 | * wait_for_readers() can release and grab again rcu_registry_lock |
f99c6e92 | 419 | * internally. |
f6b42f9c | 420 | */ |
601922a8 | 421 | wait_for_readers(®istry, NULL, &qsreaders, &acquire_group); |
708d89f0 MD |
422 | |
423 | /* | |
424 | * Put quiescent reader list back into registry. | |
425 | */ | |
426 | cds_list_splice(&qsreaders, ®istry); | |
2dfb8b5e | 427 | out: |
731ccb96 | 428 | mutex_unlock(&rcu_registry_lock); |
6abb4bd5 | 429 | mutex_unlock(&rcu_gp_lock); |
bf6822a6 | 430 | urcu_wake_all_waiters(&waiters); |
6362f68f | 431 | gp_end: |
ff2f67a0 | 432 | if (was_online) |
4477a870 | 433 | urcu_qsbr_thread_online(); |
27b940e7 PB |
434 | else |
435 | cmm_smp_mb(); | |
601922a8 OD |
436 | |
437 | cmm_annotate_group_mb_acquire(&acquire_group); | |
9f1621ca | 438 | } |
b39e1761 | 439 | #endif /* !(CAA_BITS_PER_LONG < 64) */ |
9f1621ca MD |
440 | |
441 | /* | |
442 | * library wrappers to be used by non-LGPL compatible source code. | |
443 | */ | |
444 | ||
4477a870 | 445 | void urcu_qsbr_read_lock(void) |
9f1621ca | 446 | { |
4477a870 | 447 | _urcu_qsbr_read_lock(); |
9f1621ca MD |
448 | } |
449 | ||
4477a870 | 450 | void urcu_qsbr_read_unlock(void) |
9f1621ca | 451 | { |
4477a870 | 452 | _urcu_qsbr_read_unlock(); |
9f1621ca MD |
453 | } |
454 | ||
4477a870 | 455 | int urcu_qsbr_read_ongoing(void) |
882f3357 | 456 | { |
4477a870 | 457 | return _urcu_qsbr_read_ongoing(); |
882f3357 | 458 | } |
4477a870 | 459 | void rcu_read_ongoing_qsbr(); |
882f3357 | 460 | |
4477a870 | 461 | void urcu_qsbr_quiescent_state(void) |
7ac06cef | 462 | { |
4477a870 | 463 | _urcu_qsbr_quiescent_state(); |
7ac06cef | 464 | } |
4477a870 | 465 | void rcu_quiescent_state_qsbr(); |
7ac06cef | 466 | |
4477a870 | 467 | void urcu_qsbr_thread_offline(void) |
7ac06cef | 468 | { |
4477a870 | 469 | _urcu_qsbr_thread_offline(); |
7ac06cef | 470 | } |
4477a870 | 471 | void rcu_thread_offline_qsbr(); |
7ac06cef | 472 | |
4477a870 | 473 | void urcu_qsbr_thread_online(void) |
7ac06cef | 474 | { |
4477a870 | 475 | _urcu_qsbr_thread_online(); |
7ac06cef MD |
476 | } |
477 | ||
4477a870 | 478 | void urcu_qsbr_register_thread(void) |
9f1621ca | 479 | { |
4477a870 | 480 | URCU_TLS(urcu_qsbr_reader).tid = pthread_self(); |
01477510 | 481 | urcu_posix_assert(URCU_TLS(urcu_qsbr_reader).ctr == 0); |
4f8e3380 | 482 | |
731ccb96 | 483 | mutex_lock(&rcu_registry_lock); |
01477510 | 484 | urcu_posix_assert(!URCU_TLS(urcu_qsbr_reader).registered); |
4477a870 MD |
485 | URCU_TLS(urcu_qsbr_reader).registered = 1; |
486 | cds_list_add(&URCU_TLS(urcu_qsbr_reader).node, ®istry); | |
731ccb96 | 487 | mutex_unlock(&rcu_registry_lock); |
4477a870 | 488 | _urcu_qsbr_thread_online(); |
9f1621ca MD |
489 | } |
490 | ||
4477a870 | 491 | void urcu_qsbr_unregister_thread(void) |
9f1621ca | 492 | { |
76f3022f MD |
493 | /* |
494 | * We have to make the thread offline otherwise we end up dealocking | |
495 | * with a waiting writer. | |
496 | */ | |
4477a870 | 497 | _urcu_qsbr_thread_offline(); |
01477510 | 498 | urcu_posix_assert(URCU_TLS(urcu_qsbr_reader).registered); |
4477a870 | 499 | URCU_TLS(urcu_qsbr_reader).registered = 0; |
731ccb96 | 500 | mutex_lock(&rcu_registry_lock); |
4477a870 | 501 | cds_list_del(&URCU_TLS(urcu_qsbr_reader).node); |
731ccb96 | 502 | mutex_unlock(&rcu_registry_lock); |
9f1621ca | 503 | } |
f6d18c64 | 504 | |
4477a870 | 505 | void urcu_qsbr_exit(void) |
f6d18c64 | 506 | { |
01cadde4 MD |
507 | /* |
508 | * Assertion disabled because call_rcu threads are now rcu | |
509 | * readers, and left running at exit. | |
01477510 | 510 | * urcu_posix_assert(cds_list_empty(®istry)); |
01cadde4 | 511 | */ |
90f72b8c | 512 | urcu_call_rcu_exit(); |
f6d18c64 | 513 | } |
5e77fc1f | 514 | |
5e6b23a6 | 515 | DEFINE_RCU_FLAVOR(rcu_flavor); |
541d828d | 516 | |
5e77fc1f | 517 | #include "urcu-call-rcu-impl.h" |
0376e7b2 | 518 | #include "urcu-defer-impl.h" |
111bda8f | 519 | #include "urcu-poll-impl.h" |