urcu,call_rcu: Cleanup call_rcu_data pointers before use in child
[urcu.git] / urcu-call-rcu-impl.h
CommitLineData
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1/*
2 * urcu-call-rcu.c
3 *
4 * Userspace RCU library - batch memory reclamation with kernel API
5 *
6 * Copyright (c) 2010 Paul E. McKenney <paulmck@linux.vnet.ibm.com>
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
c1d2c60b 23#define _GNU_SOURCE
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24#include <stdio.h>
25#include <pthread.h>
26#include <signal.h>
27#include <assert.h>
28#include <stdlib.h>
6d841bc2 29#include <stdint.h>
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30#include <string.h>
31#include <errno.h>
32#include <poll.h>
33#include <sys/time.h>
b57aee66 34#include <unistd.h>
c1d2c60b 35#include <sched.h>
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36
37#include "config.h"
38#include "urcu/wfqueue.h"
39#include "urcu-call-rcu.h"
40#include "urcu-pointer.h"
3c24913f 41#include "urcu/list.h"
41849996 42#include "urcu/futex.h"
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43
44/* Data structure that identifies a call_rcu thread. */
45
46struct call_rcu_data {
47 struct cds_wfq_queue cbs;
48 unsigned long flags;
6d841bc2 49 int32_t futex;
73987721 50 unsigned long qlen; /* maintained for debugging. */
b57aee66 51 pthread_t tid;
c1d2c60b 52 int cpu_affinity;
3c24913f 53 struct cds_list_head list;
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54} __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
55
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56/*
57 * List of all call_rcu_data structures to keep valgrind happy.
58 * Protected by call_rcu_mutex.
59 */
60
61CDS_LIST_HEAD(call_rcu_data_list);
62
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63/* Link a thread using call_rcu() to its call_rcu thread. */
64
65static __thread struct call_rcu_data *thread_call_rcu_data;
66
67/* Guard call_rcu thread creation. */
68
69static pthread_mutex_t call_rcu_mutex = PTHREAD_MUTEX_INITIALIZER;
70
71/* If a given thread does not have its own call_rcu thread, this is default. */
72
73static struct call_rcu_data *default_call_rcu_data;
74
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75/*
76 * If the sched_getcpu() and sysconf(_SC_NPROCESSORS_CONF) calls are
77 * available, then we can have call_rcu threads assigned to individual
78 * CPUs rather than only to specific threads.
79 */
80
81#if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF)
82
83/*
84 * Pointer to array of pointers to per-CPU call_rcu_data structures
85 * and # CPUs.
86 */
87
88static struct call_rcu_data **per_cpu_call_rcu_data;
89static long maxcpus;
90
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91static void maxcpus_reset(void)
92{
93 maxcpus = 0;
94}
95
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96/* Allocate the array if it has not already been allocated. */
97
98static void alloc_cpu_call_rcu_data(void)
99{
100 struct call_rcu_data **p;
101 static int warned = 0;
102
103 if (maxcpus != 0)
104 return;
105 maxcpus = sysconf(_SC_NPROCESSORS_CONF);
106 if (maxcpus <= 0) {
107 return;
108 }
109 p = malloc(maxcpus * sizeof(*per_cpu_call_rcu_data));
110 if (p != NULL) {
111 memset(p, '\0', maxcpus * sizeof(*per_cpu_call_rcu_data));
112 per_cpu_call_rcu_data = p;
113 } else {
114 if (!warned) {
115 fprintf(stderr, "[error] liburcu: unable to allocate per-CPU pointer array\n");
116 }
117 warned = 1;
118 }
119}
120
121#else /* #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */
122
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123/*
124 * per_cpu_call_rcu_data should be constant, but some functions below, used both
125 * for cases where cpu number is available and not available, assume it it not
126 * constant.
127 */
128static struct call_rcu_data **per_cpu_call_rcu_data = NULL;
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129static const long maxcpus = -1;
130
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131static void maxcpus_reset(void)
132{
133}
134
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135static void alloc_cpu_call_rcu_data(void)
136{
137}
138
139static int sched_getcpu(void)
140{
141 return -1;
142}
143
144#endif /* #else #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */
145
146/* Acquire the specified pthread mutex. */
147
148static void call_rcu_lock(pthread_mutex_t *pmp)
149{
150 if (pthread_mutex_lock(pmp) != 0) {
151 perror("pthread_mutex_lock");
152 exit(-1);
153 }
154}
155
156/* Release the specified pthread mutex. */
157
158static void call_rcu_unlock(pthread_mutex_t *pmp)
159{
160 if (pthread_mutex_unlock(pmp) != 0) {
161 perror("pthread_mutex_unlock");
162 exit(-1);
163 }
164}
165
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166#if HAVE_SCHED_SETAFFINITY
167static
168int set_thread_cpu_affinity(struct call_rcu_data *crdp)
169{
170 cpu_set_t mask;
171
172 if (crdp->cpu_affinity < 0)
173 return 0;
174
175 CPU_ZERO(&mask);
176 CPU_SET(crdp->cpu_affinity, &mask);
177#if SCHED_SETAFFINITY_ARGS == 2
178 return sched_setaffinity(0, &mask);
179#else
180 return sched_setaffinity(0, sizeof(mask), &mask);
181#endif
182}
183#else
184static
185int set_thread_cpu_affinity(struct call_rcu_data *crdp)
186{
187 return 0;
188}
189#endif
190
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191static void call_rcu_wait(struct call_rcu_data *crdp)
192{
193 /* Read call_rcu list before read futex */
194 cmm_smp_mb();
195 if (uatomic_read(&crdp->futex) == -1)
196 futex_async(&crdp->futex, FUTEX_WAIT, -1,
197 NULL, NULL, 0);
198}
199
200static void call_rcu_wake_up(struct call_rcu_data *crdp)
201{
202 /* Write to call_rcu list before reading/writing futex */
203 cmm_smp_mb();
204 if (unlikely(uatomic_read(&crdp->futex) == -1)) {
205 uatomic_set(&crdp->futex, 0);
206 futex_async(&crdp->futex, FUTEX_WAKE, 1,
207 NULL, NULL, 0);
208 }
209}
210
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211/* This is the code run by each call_rcu thread. */
212
213static void *call_rcu_thread(void *arg)
214{
215 unsigned long cbcount;
216 struct cds_wfq_node *cbs;
217 struct cds_wfq_node **cbs_tail;
218 struct call_rcu_data *crdp = (struct call_rcu_data *)arg;
219 struct rcu_head *rhp;
2870aa1e 220 int rt = !!(uatomic_read(&crdp->flags) & URCU_CALL_RCU_RT);
b57aee66 221
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222 if (set_thread_cpu_affinity(crdp) != 0) {
223 perror("pthread_setaffinity_np");
224 exit(-1);
225 }
226
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227 /*
228 * If callbacks take a read-side lock, we need to be registered.
229 */
230 rcu_register_thread();
231
b57aee66 232 thread_call_rcu_data = crdp;
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233 if (!rt) {
234 uatomic_dec(&crdp->futex);
235 /* Decrement futex before reading call_rcu list */
236 cmm_smp_mb();
237 }
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238 for (;;) {
239 if (&crdp->cbs.head != _CMM_LOAD_SHARED(crdp->cbs.tail)) {
240 while ((cbs = _CMM_LOAD_SHARED(crdp->cbs.head)) == NULL)
241 poll(NULL, 0, 1);
242 _CMM_STORE_SHARED(crdp->cbs.head, NULL);
243 cbs_tail = (struct cds_wfq_node **)
244 uatomic_xchg(&crdp->cbs.tail, &crdp->cbs.head);
245 synchronize_rcu();
246 cbcount = 0;
247 do {
248 while (cbs->next == NULL &&
249 &cbs->next != cbs_tail)
250 poll(NULL, 0, 1);
251 if (cbs == &crdp->cbs.dummy) {
252 cbs = cbs->next;
253 continue;
254 }
255 rhp = (struct rcu_head *)cbs;
256 cbs = cbs->next;
257 rhp->func(rhp);
258 cbcount++;
259 } while (cbs != NULL);
260 uatomic_sub(&crdp->qlen, cbcount);
261 }
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262 if (uatomic_read(&crdp->flags) & URCU_CALL_RCU_STOP)
263 break;
765f3ead 264 rcu_thread_offline();
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265 if (!rt) {
266 if (&crdp->cbs.head
267 == _CMM_LOAD_SHARED(crdp->cbs.tail)) {
268 call_rcu_wait(crdp);
269 poll(NULL, 0, 10);
270 uatomic_dec(&crdp->futex);
c768e45e 271 /*
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272 * Decrement futex before reading
273 * call_rcu list.
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274 */
275 cmm_smp_mb();
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276 } else {
277 poll(NULL, 0, 10);
c768e45e 278 }
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279 } else {
280 poll(NULL, 0, 10);
b57aee66 281 }
765f3ead 282 rcu_thread_online();
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283 }
284 if (!rt) {
285 /*
286 * Read call_rcu list before write futex.
287 */
288 cmm_smp_mb();
289 uatomic_set(&crdp->futex, 0);
b57aee66 290 }
2870aa1e 291 uatomic_or(&crdp->flags, URCU_CALL_RCU_STOPPED);
765f3ead 292 rcu_unregister_thread();
7106ddf8 293 return NULL;
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294}
295
296/*
297 * Create both a call_rcu thread and the corresponding call_rcu_data
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298 * structure, linking the structure in as specified. Caller must hold
299 * call_rcu_mutex.
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300 */
301
3c24913f 302static void call_rcu_data_init(struct call_rcu_data **crdpp,
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303 unsigned long flags,
304 int cpu_affinity)
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305{
306 struct call_rcu_data *crdp;
307
308 crdp = malloc(sizeof(*crdp));
309 if (crdp == NULL) {
310 fprintf(stderr, "Out of memory.\n");
311 exit(-1);
312 }
313 memset(crdp, '\0', sizeof(*crdp));
314 cds_wfq_init(&crdp->cbs);
315 crdp->qlen = 0;
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316 crdp->futex = 0;
317 crdp->flags = flags;
3c24913f 318 cds_list_add(&crdp->list, &call_rcu_data_list);
c1d2c60b 319 crdp->cpu_affinity = cpu_affinity;
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320 cmm_smp_mb(); /* Structure initialized before pointer is planted. */
321 *crdpp = crdp;
322 if (pthread_create(&crdp->tid, NULL, call_rcu_thread, crdp) != 0) {
323 perror("pthread_create");
324 exit(-1);
325 }
326}
327
328/*
329 * Return a pointer to the call_rcu_data structure for the specified
330 * CPU, returning NULL if there is none. We cannot automatically
331 * created it because the platform we are running on might not define
332 * sched_getcpu().
333 */
334
335struct call_rcu_data *get_cpu_call_rcu_data(int cpu)
336{
337 static int warned = 0;
338
339 if (per_cpu_call_rcu_data == NULL)
340 return NULL;
341 if (!warned && maxcpus > 0 && (cpu < 0 || maxcpus <= cpu)) {
342 fprintf(stderr, "[error] liburcu: get CPU # out of range\n");
343 warned = 1;
344 }
345 if (cpu < 0 || maxcpus <= cpu)
346 return NULL;
347 return per_cpu_call_rcu_data[cpu];
348}
349
350/*
351 * Return the tid corresponding to the call_rcu thread whose
352 * call_rcu_data structure is specified.
353 */
354
355pthread_t get_call_rcu_thread(struct call_rcu_data *crdp)
356{
357 return crdp->tid;
358}
359
360/*
361 * Create a call_rcu_data structure (with thread) and return a pointer.
362 */
363
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364static struct call_rcu_data *__create_call_rcu_data(unsigned long flags,
365 int cpu_affinity)
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366{
367 struct call_rcu_data *crdp;
368
c1d2c60b 369 call_rcu_data_init(&crdp, flags, cpu_affinity);
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370 return crdp;
371}
372
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373struct call_rcu_data *create_call_rcu_data(unsigned long flags,
374 int cpu_affinity)
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375{
376 struct call_rcu_data *crdp;
377
378 call_rcu_lock(&call_rcu_mutex);
c1d2c60b 379 crdp = __create_call_rcu_data(flags, cpu_affinity);
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380 call_rcu_unlock(&call_rcu_mutex);
381 return crdp;
382}
383
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384/*
385 * Set the specified CPU to use the specified call_rcu_data structure.
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386 *
387 * Use NULL to remove a CPU's call_rcu_data structure, but it is
388 * the caller's responsibility to dispose of the removed structure.
389 * Use get_cpu_call_rcu_data() to obtain a pointer to the old structure
390 * (prior to NULLing it out, of course).
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391 */
392
393int set_cpu_call_rcu_data(int cpu, struct call_rcu_data *crdp)
394{
dcfc8165 395 static int warned = 0;
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396
397 call_rcu_lock(&call_rcu_mutex);
f3776786 398 alloc_cpu_call_rcu_data();
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399 if (cpu < 0 || maxcpus <= cpu) {
400 if (!warned) {
401 fprintf(stderr, "[error] liburcu: set CPU # out of range\n");
402 warned = 1;
403 }
404 call_rcu_unlock(&call_rcu_mutex);
405 errno = EINVAL;
406 return -EINVAL;
407 }
53a55535 408
b57aee66 409 if (per_cpu_call_rcu_data == NULL) {
3670fef2 410 call_rcu_unlock(&call_rcu_mutex);
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411 errno = ENOMEM;
412 return -ENOMEM;
413 }
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414
415 if (per_cpu_call_rcu_data[cpu] != NULL && crdp != NULL) {
416 call_rcu_unlock(&call_rcu_mutex);
417 errno = EEXIST;
418 return -EEXIST;
419 }
420
b57aee66 421 per_cpu_call_rcu_data[cpu] = crdp;
3670fef2 422 call_rcu_unlock(&call_rcu_mutex);
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423 return 0;
424}
425
426/*
427 * Return a pointer to the default call_rcu_data structure, creating
428 * one if need be. Because we never free call_rcu_data structures,
429 * we don't need to be in an RCU read-side critical section.
430 */
431
432struct call_rcu_data *get_default_call_rcu_data(void)
433{
434 if (default_call_rcu_data != NULL)
435 return rcu_dereference(default_call_rcu_data);
436 call_rcu_lock(&call_rcu_mutex);
437 if (default_call_rcu_data != NULL) {
438 call_rcu_unlock(&call_rcu_mutex);
439 return default_call_rcu_data;
440 }
c1d2c60b 441 call_rcu_data_init(&default_call_rcu_data, 0, -1);
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442 call_rcu_unlock(&call_rcu_mutex);
443 return default_call_rcu_data;
444}
445
446/*
447 * Return the call_rcu_data structure that applies to the currently
448 * running thread. Any call_rcu_data structure assigned specifically
449 * to this thread has first priority, followed by any call_rcu_data
450 * structure assigned to the CPU on which the thread is running,
451 * followed by the default call_rcu_data structure. If there is not
452 * yet a default call_rcu_data structure, one will be created.
453 */
454struct call_rcu_data *get_call_rcu_data(void)
455{
9744f3bb 456 struct call_rcu_data *crd;
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457
458 if (thread_call_rcu_data != NULL)
459 return thread_call_rcu_data;
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460
461 if (maxcpus > 0) {
462 crd = get_cpu_call_rcu_data(sched_getcpu());
463 if (crd)
464 return crd;
b57aee66 465 }
9744f3bb 466
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467 return get_default_call_rcu_data();
468}
469
470/*
471 * Return a pointer to this task's call_rcu_data if there is one.
472 */
473
474struct call_rcu_data *get_thread_call_rcu_data(void)
475{
476 return thread_call_rcu_data;
477}
478
479/*
480 * Set this task's call_rcu_data structure as specified, regardless
481 * of whether or not this task already had one. (This allows switching
482 * to and from real-time call_rcu threads, for example.)
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483 *
484 * Use NULL to remove a thread's call_rcu_data structure, but it is
485 * the caller's responsibility to dispose of the removed structure.
486 * Use get_thread_call_rcu_data() to obtain a pointer to the old structure
487 * (prior to NULLing it out, of course).
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488 */
489
490void set_thread_call_rcu_data(struct call_rcu_data *crdp)
491{
492 thread_call_rcu_data = crdp;
493}
494
495/*
496 * Create a separate call_rcu thread for each CPU. This does not
497 * replace a pre-existing call_rcu thread -- use the set_cpu_call_rcu_data()
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498 * function if you want that behavior. Should be paired with
499 * free_all_cpu_call_rcu_data() to teardown these call_rcu worker
500 * threads.
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501 */
502
503int create_all_cpu_call_rcu_data(unsigned long flags)
504{
505 int i;
506 struct call_rcu_data *crdp;
507 int ret;
508
509 call_rcu_lock(&call_rcu_mutex);
510 alloc_cpu_call_rcu_data();
511 call_rcu_unlock(&call_rcu_mutex);
512 if (maxcpus <= 0) {
513 errno = EINVAL;
514 return -EINVAL;
515 }
516 if (per_cpu_call_rcu_data == NULL) {
517 errno = ENOMEM;
518 return -ENOMEM;
519 }
520 for (i = 0; i < maxcpus; i++) {
521 call_rcu_lock(&call_rcu_mutex);
522 if (get_cpu_call_rcu_data(i)) {
523 call_rcu_unlock(&call_rcu_mutex);
524 continue;
525 }
c1d2c60b 526 crdp = __create_call_rcu_data(flags, i);
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527 if (crdp == NULL) {
528 call_rcu_unlock(&call_rcu_mutex);
529 errno = ENOMEM;
530 return -ENOMEM;
531 }
532 call_rcu_unlock(&call_rcu_mutex);
533 if ((ret = set_cpu_call_rcu_data(i, crdp)) != 0) {
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534 call_rcu_data_free(crdp);
535
536 /* it has been created by other thread */
537 if (ret == -EEXIST)
538 continue;
539
540 return ret;
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541 }
542 }
543 return 0;
544}
545
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546/*
547 * Wake up the call_rcu thread corresponding to the specified
548 * call_rcu_data structure.
549 */
550static void wake_call_rcu_thread(struct call_rcu_data *crdp)
551{
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552 if (!(_CMM_LOAD_SHARED(crdp->flags) & URCU_CALL_RCU_RT))
553 call_rcu_wake_up(crdp);
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554}
555
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556/*
557 * Schedule a function to be invoked after a following grace period.
558 * This is the only function that must be called -- the others are
559 * only present to allow applications to tune their use of RCU for
560 * maximum performance.
561 *
562 * Note that unless a call_rcu thread has not already been created,
563 * the first invocation of call_rcu() will create one. So, if you
564 * need the first invocation of call_rcu() to be fast, make sure
565 * to create a call_rcu thread first. One way to accomplish this is
566 * "get_call_rcu_data();", and another is create_all_cpu_call_rcu_data().
567 */
568
569void call_rcu(struct rcu_head *head,
570 void (*func)(struct rcu_head *head))
571{
572 struct call_rcu_data *crdp;
573
574 cds_wfq_node_init(&head->next);
575 head->func = func;
576 crdp = get_call_rcu_data();
577 cds_wfq_enqueue(&crdp->cbs, &head->next);
578 uatomic_inc(&crdp->qlen);
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579 wake_call_rcu_thread(crdp);
580}
581
582/*
583 * Free up the specified call_rcu_data structure, terminating the
584 * associated call_rcu thread. The caller must have previously
585 * removed the call_rcu_data structure from per-thread or per-CPU
586 * usage. For example, set_cpu_call_rcu_data(cpu, NULL) for per-CPU
587 * call_rcu_data structures or set_thread_call_rcu_data(NULL) for
588 * per-thread call_rcu_data structures.
589 *
590 * We silently refuse to free up the default call_rcu_data structure
591 * because that is where we put any leftover callbacks. Note that
592 * the possibility of self-spawning callbacks makes it impossible
593 * to execute all the callbacks in finite time without putting any
594 * newly spawned callbacks somewhere else. The "somewhere else" of
595 * last resort is the default call_rcu_data structure.
596 *
597 * We also silently refuse to free NULL pointers. This simplifies
598 * the calling code.
599 */
600void call_rcu_data_free(struct call_rcu_data *crdp)
601{
602 struct cds_wfq_node *cbs;
603 struct cds_wfq_node **cbs_tail;
604 struct cds_wfq_node **cbs_endprev;
605
606 if (crdp == NULL || crdp == default_call_rcu_data) {
607 return;
608 }
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609 if ((uatomic_read(&crdp->flags) & URCU_CALL_RCU_STOPPED) == 0) {
610 uatomic_or(&crdp->flags, URCU_CALL_RCU_STOP);
7106ddf8 611 wake_call_rcu_thread(crdp);
2870aa1e 612 while ((uatomic_read(&crdp->flags) & URCU_CALL_RCU_STOPPED) == 0)
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613 poll(NULL, 0, 1);
614 }
615 if (&crdp->cbs.head != _CMM_LOAD_SHARED(crdp->cbs.tail)) {
616 while ((cbs = _CMM_LOAD_SHARED(crdp->cbs.head)) == NULL)
617 poll(NULL, 0, 1);
618 _CMM_STORE_SHARED(crdp->cbs.head, NULL);
619 cbs_tail = (struct cds_wfq_node **)
620 uatomic_xchg(&crdp->cbs.tail, &crdp->cbs.head);
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621 /* Create default call rcu data if need be */
622 (void) get_default_call_rcu_data();
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623 cbs_endprev = (struct cds_wfq_node **)
624 uatomic_xchg(&default_call_rcu_data, cbs_tail);
625 *cbs_endprev = cbs;
626 uatomic_add(&default_call_rcu_data->qlen,
627 uatomic_read(&crdp->qlen));
1e92aa15 628 wake_call_rcu_thread(default_call_rcu_data);
7106ddf8 629 }
59dc9e9d 630
b75dffe6 631 call_rcu_lock(&call_rcu_mutex);
59dc9e9d 632 cds_list_del(&crdp->list);
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633 call_rcu_unlock(&call_rcu_mutex);
634
59dc9e9d 635 free(crdp);
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636}
637
638/*
639 * Clean up all the per-CPU call_rcu threads.
640 */
641void free_all_cpu_call_rcu_data(void)
642{
643 int cpu;
644 struct call_rcu_data *crdp;
645
646 if (maxcpus <= 0)
647 return;
648 for (cpu = 0; cpu < maxcpus; cpu++) {
649 crdp = get_cpu_call_rcu_data(cpu);
650 if (crdp == NULL)
651 continue;
652 set_cpu_call_rcu_data(cpu, NULL);
653 call_rcu_data_free(crdp);
654 }
655}
656
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657/*
658 * Acquire the call_rcu_mutex in order to ensure that the child sees
659 * all of the call_rcu() data structures in a consistent state.
660 * Suitable for pthread_atfork() and friends.
661 */
662void call_rcu_before_fork(void)
663{
664 call_rcu_lock(&call_rcu_mutex);
665}
666
667/*
668 * Clean up call_rcu data structures in the parent of a successful fork()
669 * that is not followed by exec() in the child. Suitable for
670 * pthread_atfork() and friends.
671 */
672void call_rcu_after_fork_parent(void)
673{
674 call_rcu_unlock(&call_rcu_mutex);
675}
676
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677/*
678 * Clean up call_rcu data structures in the child of a successful fork()
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679 * that is not followed by exec(). Suitable for pthread_atfork() and
680 * friends.
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681 */
682void call_rcu_after_fork_child(void)
683{
077ff173 684 struct call_rcu_data *crdp, *next;
7106ddf8 685
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686 /* Release the mutex. */
687 call_rcu_unlock(&call_rcu_mutex);
688
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689 /* Do nothing when call_rcu() has not been used */
690 if (cds_list_empty(&call_rcu_data_list))
691 return;
692
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693 /*
694 * Allocate a new default call_rcu_data structure in order
695 * to get a working call_rcu thread to go with it.
696 */
697 default_call_rcu_data = NULL;
698 (void)get_default_call_rcu_data();
699
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700 /* Cleanup call_rcu_data pointers before use */
701 maxcpus_reset();
702 free(per_cpu_call_rcu_data);
703 per_cpu_call_rcu_data = NULL;
704 thread_call_rcu_data = NULL;
705
7106ddf8 706 /* Dispose of all of the rest of the call_rcu_data structures. */
077ff173 707 cds_list_for_each_entry_safe(crdp, next, &call_rcu_data_list, list) {
7106ddf8 708 if (crdp == default_call_rcu_data)
077ff173 709 continue;
2870aa1e 710 uatomic_set(&crdp->flags, URCU_CALL_RCU_STOPPED);
7106ddf8 711 call_rcu_data_free(crdp);
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712 }
713}
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