1 // SPDX-FileCopyrightText: 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2 // SPDX-FileCopyrightText: 2010 Paolo Bonzini <pbonzini@redhat.com>
4 // SPDX-License-Identifier: GPL-2.0-or-later
7 * Userspace RCU library - example RCU-based lock-free stack
16 #include <sys/types.h>
22 #include <urcu/arch.h>
23 #include <urcu/assert.h>
24 #include <urcu/tls-compat.h>
25 #include <urcu/uatomic.h>
26 #include "thread-id.h"
28 /* hardcoded number of CPUs */
31 #ifndef DYNAMIC_LINK_TEST
34 #include <urcu/wfstack.h>
37 * External synchronization used.
44 static enum test_sync test_sync
;
46 static int test_force_sync
;
48 static volatile int test_stop_enqueue
, test_stop_dequeue
;
50 static unsigned long rduration
;
52 static unsigned long duration
;
54 /* read-side C.S. duration, in loops */
55 static unsigned long wdelay
;
57 static inline void loop_sleep(unsigned long loops
)
63 static int verbose_mode
;
65 static int test_pop
, test_pop_all
, test_wait_empty
;
66 static unsigned int test_enqueue_stopped
;
68 #define printf_verbose(fmt, args...) \
71 printf(fmt, ## args); \
74 static unsigned int cpu_affinities
[NR_CPUS
];
75 static unsigned int next_aff
= 0;
76 static int use_affinity
= 0;
78 pthread_mutex_t affinity_mutex
= PTHREAD_MUTEX_INITIALIZER
;
80 static void set_affinity(void)
82 #ifdef HAVE_SCHED_SETAFFINITY
85 #endif /* HAVE_SCHED_SETAFFINITY */
90 #ifdef HAVE_SCHED_SETAFFINITY
91 ret
= pthread_mutex_lock(&affinity_mutex
);
93 perror("Error in pthread mutex lock");
96 cpu
= cpu_affinities
[next_aff
++];
97 ret
= pthread_mutex_unlock(&affinity_mutex
);
99 perror("Error in pthread mutex unlock");
105 sched_setaffinity(0, sizeof(mask
), &mask
);
106 #endif /* HAVE_SCHED_SETAFFINITY */
110 * returns 0 if test should end.
112 static int test_duration_dequeue(void)
114 return !uatomic_load(&test_stop_dequeue
, CMM_RELAXED
);
117 static int test_duration_enqueue(void)
119 return !uatomic_load(&test_stop_enqueue
, CMM_RELAXED
);
122 static DEFINE_URCU_TLS(unsigned long long, nr_dequeues
);
123 static DEFINE_URCU_TLS(unsigned long long, nr_enqueues
);
125 static DEFINE_URCU_TLS(unsigned long long, nr_successful_dequeues
);
126 static DEFINE_URCU_TLS(unsigned long long, nr_successful_enqueues
);
127 static DEFINE_URCU_TLS(unsigned long long, nr_empty_dest_enqueues
);
128 static DEFINE_URCU_TLS(unsigned long long, nr_pop_all
);
129 static DEFINE_URCU_TLS(unsigned long long, nr_pop_last
);
131 static unsigned int nr_enqueuers
;
132 static unsigned int nr_dequeuers
;
134 static struct cds_wfs_stack s
;
136 static void *thr_enqueuer(void *_count
)
138 unsigned long long *count
= _count
;
141 printf_verbose("thread_begin %s, tid %lu\n",
142 "enqueuer", urcu_get_thread_id());
149 struct cds_wfs_node
*node
= malloc(sizeof(*node
));
152 cds_wfs_node_init(node
);
153 was_nonempty
= cds_wfs_push(&s
, node
);
154 URCU_TLS(nr_successful_enqueues
)++;
156 URCU_TLS(nr_empty_dest_enqueues
)++;
158 if (caa_unlikely(wdelay
))
161 URCU_TLS(nr_enqueues
)++;
162 if (caa_unlikely(!test_duration_enqueue()))
166 uatomic_inc(&test_enqueue_stopped
);
167 count
[0] = URCU_TLS(nr_enqueues
);
168 count
[1] = URCU_TLS(nr_successful_enqueues
);
169 count
[2] = URCU_TLS(nr_empty_dest_enqueues
);
170 printf_verbose("enqueuer thread_end, tid %lu, "
171 "enqueues %llu successful_enqueues %llu, "
172 "empty_dest_enqueues %llu\n",
173 urcu_get_thread_id(),
174 URCU_TLS(nr_enqueues
),
175 URCU_TLS(nr_successful_enqueues
),
176 URCU_TLS(nr_empty_dest_enqueues
));
181 static void do_test_pop(enum test_sync sync
)
183 struct cds_wfs_node
*node
;
186 if (sync
== TEST_SYNC_MUTEX
)
187 cds_wfs_pop_lock(&s
);
188 node
= __cds_wfs_pop_with_state_blocking(&s
, &state
);
189 if (sync
== TEST_SYNC_MUTEX
)
190 cds_wfs_pop_unlock(&s
);
193 if (state
& CDS_WFS_STATE_LAST
)
194 URCU_TLS(nr_pop_last
)++;
196 URCU_TLS(nr_successful_dequeues
)++;
198 URCU_TLS(nr_dequeues
)++;
201 static void do_test_pop_all(enum test_sync sync
)
203 struct cds_wfs_head
*head
;
204 struct cds_wfs_node
*node
, *n
;
206 if (sync
== TEST_SYNC_MUTEX
)
207 cds_wfs_pop_lock(&s
);
208 head
= __cds_wfs_pop_all(&s
);
209 if (sync
== TEST_SYNC_MUTEX
)
210 cds_wfs_pop_unlock(&s
);
213 if (cds_wfs_first(head
) == NULL
)
216 URCU_TLS(nr_pop_all
)++;
217 URCU_TLS(nr_pop_last
)++;
219 cds_wfs_for_each_blocking_safe(head
, node
, n
) {
221 URCU_TLS(nr_successful_dequeues
)++;
222 URCU_TLS(nr_dequeues
)++;
226 static void *thr_dequeuer(void *_count
)
228 unsigned long long *count
= _count
;
229 unsigned int counter
= 0;
231 printf_verbose("thread_begin %s, tid %lu\n",
232 "dequeuer", urcu_get_thread_id());
238 urcu_posix_assert(test_pop
|| test_pop_all
);
241 if (test_pop
&& test_pop_all
) {
243 do_test_pop(test_sync
);
245 do_test_pop_all(test_sync
);
249 do_test_pop(test_sync
);
251 do_test_pop_all(test_sync
);
254 if (caa_unlikely(!test_duration_dequeue()))
256 if (caa_unlikely(rduration
))
257 loop_sleep(rduration
);
260 printf_verbose("dequeuer thread_end, tid %lu, "
261 "dequeues %llu, successful_dequeues %llu "
262 "pop_all %llu pop_last %llu\n",
263 urcu_get_thread_id(),
264 URCU_TLS(nr_dequeues
), URCU_TLS(nr_successful_dequeues
),
265 URCU_TLS(nr_pop_all
),
266 URCU_TLS(nr_pop_last
));
267 count
[0] = URCU_TLS(nr_dequeues
);
268 count
[1] = URCU_TLS(nr_successful_dequeues
);
269 count
[2] = URCU_TLS(nr_pop_all
);
270 count
[3] = URCU_TLS(nr_pop_last
);
274 static void test_end(unsigned long long *nr_dequeues_l
,
275 unsigned long long *nr_pop_last_l
)
277 struct cds_wfs_node
*node
;
281 node
= cds_wfs_pop_with_state_blocking(&s
, &state
);
283 if (state
& CDS_WFS_STATE_LAST
)
291 static void show_usage(char **argv
)
293 printf("Usage : %s nr_dequeuers nr_enqueuers duration (s) <OPTIONS>\n",
295 printf("OPTIONS:\n");
296 printf(" [-d delay] (enqueuer period (in loops))\n");
297 printf(" [-c duration] (dequeuer period (in loops))\n");
298 printf(" [-v] (verbose output)\n");
299 printf(" [-a cpu#] [-a cpu#]... (affinity)\n");
300 printf(" [-p] (test pop)\n");
301 printf(" [-P] (test pop_all, enabled by default)\n");
302 printf(" [-M] (use mutex external synchronization)\n");
303 printf(" Note: default: no external synchronization used.\n");
304 printf(" [-f] (force user-provided synchronization)\n");
305 printf(" [-w] Wait for dequeuer to empty stack\n");
309 int main(int argc
, char **argv
)
312 pthread_t
*tid_enqueuer
, *tid_dequeuer
;
314 unsigned long long *count_enqueuer
, *count_dequeuer
;
315 unsigned long long tot_enqueues
= 0, tot_dequeues
= 0;
316 unsigned long long tot_successful_enqueues
= 0,
317 tot_successful_dequeues
= 0,
318 tot_empty_dest_enqueues
= 0,
319 tot_pop_all
= 0, tot_pop_last
= 0;
320 unsigned long long end_dequeues
= 0;
321 int i
, a
, retval
= 0;
329 err
= sscanf(argv
[1], "%u", &nr_dequeuers
);
335 err
= sscanf(argv
[2], "%u", &nr_enqueuers
);
341 err
= sscanf(argv
[3], "%lu", &duration
);
347 for (i
= 4; i
< argc
; i
++) {
348 if (argv
[i
][0] != '-')
350 switch (argv
[i
][1]) {
357 cpu_affinities
[next_aff
++] = a
;
359 printf_verbose("Adding CPU %d affinity\n", a
);
366 rduration
= atol(argv
[++i
]);
373 wdelay
= atol(argv
[++i
]);
385 test_sync
= TEST_SYNC_MUTEX
;
396 /* activate pop_all test by default */
397 if (!test_pop
&& !test_pop_all
)
400 if (test_sync
== TEST_SYNC_NONE
&& nr_dequeuers
> 1 && test_pop
) {
401 if (test_force_sync
) {
402 fprintf(stderr
, "[WARNING] Using pop concurrently "
403 "with other pop or pop_all without external "
404 "synchronization. Expect run-time failure.\n");
406 printf("Enforcing mutex synchronization\n");
407 test_sync
= TEST_SYNC_MUTEX
;
411 printf_verbose("running test for %lu seconds, %u enqueuers, "
413 duration
, nr_enqueuers
, nr_dequeuers
);
415 printf_verbose("pop test activated.\n");
417 printf_verbose("pop_all test activated.\n");
418 if (test_sync
== TEST_SYNC_MUTEX
)
419 printf_verbose("External sync: mutex.\n");
421 printf_verbose("External sync: none.\n");
423 printf_verbose("Wait for dequeuers to empty stack.\n");
424 printf_verbose("Writer delay : %lu loops.\n", rduration
);
425 printf_verbose("Reader duration : %lu loops.\n", wdelay
);
426 printf_verbose("thread %-6s, tid %lu\n",
427 "main", urcu_get_thread_id());
429 tid_enqueuer
= calloc(nr_enqueuers
, sizeof(*tid_enqueuer
));
430 tid_dequeuer
= calloc(nr_dequeuers
, sizeof(*tid_dequeuer
));
431 count_enqueuer
= calloc(nr_enqueuers
, 3 * sizeof(*count_enqueuer
));
432 count_dequeuer
= calloc(nr_dequeuers
, 4 * sizeof(*count_dequeuer
));
437 for (i_thr
= 0; i_thr
< nr_enqueuers
; i_thr
++) {
438 err
= pthread_create(&tid_enqueuer
[i
], NULL
, thr_enqueuer
,
439 &count_enqueuer
[3 * i_thr
]);
443 for (i_thr
= 0; i_thr
< nr_dequeuers
; i_thr
++) {
444 err
= pthread_create(&tid_dequeuer
[i_thr
], NULL
, thr_dequeuer
,
445 &count_dequeuer
[4 * i_thr
]);
454 for (i_thr
= 0; i_thr
< duration
; i_thr
++) {
457 fwrite(".", sizeof(char), 1, stdout
);
462 uatomic_store(&test_stop_enqueue
, 1, CMM_RELEASE
);
464 if (test_wait_empty
) {
465 while (nr_enqueuers
!= uatomic_read(&test_enqueue_stopped
)) {
468 while (!cds_wfs_empty(&s
)) {
473 uatomic_store(&test_stop_dequeue
, 1, CMM_RELAXED
);
475 for (i_thr
= 0; i_thr
< nr_enqueuers
; i_thr
++) {
476 err
= pthread_join(tid_enqueuer
[i_thr
], &tret
);
479 tot_enqueues
+= count_enqueuer
[3 * i_thr
];
480 tot_successful_enqueues
+= count_enqueuer
[3 * i_thr
+ 1];
481 tot_empty_dest_enqueues
+= count_enqueuer
[3 * i_thr
+ 2];
483 for (i_thr
= 0; i_thr
< nr_dequeuers
; i_thr
++) {
484 err
= pthread_join(tid_dequeuer
[i_thr
], &tret
);
487 tot_dequeues
+= count_dequeuer
[4 * i_thr
];
488 tot_successful_dequeues
+= count_dequeuer
[4 * i_thr
+ 1];
489 tot_pop_all
+= count_dequeuer
[4 * i_thr
+ 2];
490 tot_pop_last
+= count_dequeuer
[4 * i_thr
+ 3];
493 test_end(&end_dequeues
, &tot_pop_last
);
495 printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
496 tot_enqueues
, tot_dequeues
);
497 printf_verbose("total number of successful enqueues : %llu, "
498 "enqueues to empty dest : %llu, "
499 "successful dequeues %llu, "
500 "pop_all : %llu, pop_last : %llu\n",
501 tot_successful_enqueues
,
502 tot_empty_dest_enqueues
,
503 tot_successful_dequeues
,
504 tot_pop_all
, tot_pop_last
);
505 printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
507 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
508 "successful enqueues %12llu enqueues to empty dest %12llu "
509 "successful dequeues %12llu pop_all %12llu "
510 "pop_last %llu end_dequeues %llu nr_ops %12llu\n",
511 argv
[0], duration
, nr_enqueuers
, wdelay
,
512 nr_dequeuers
, rduration
, tot_enqueues
, tot_dequeues
,
513 tot_successful_enqueues
,
514 tot_empty_dest_enqueues
,
515 tot_successful_dequeues
, tot_pop_all
, tot_pop_last
,
517 tot_enqueues
+ tot_dequeues
);
518 if (tot_successful_enqueues
!= tot_successful_dequeues
+ end_dequeues
) {
519 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
520 "succ. dequeues + end dequeues %llu.\n",
521 tot_successful_enqueues
,
522 tot_successful_dequeues
+ end_dequeues
);
526 * The enqueuer should see exactly as many empty queues than the
527 * number of non-empty stacks dequeued.
529 if (tot_empty_dest_enqueues
!= tot_pop_last
) {
530 printf("WARNING! Discrepancy between empty enqueue (%llu) and "
531 "number of pop last (%llu)\n",
532 tot_empty_dest_enqueues
,
538 free(count_enqueuer
);
539 free(count_dequeuer
);