4 * Userspace RCU library - example RCU-based lock-free stack
6 * Copyright February 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 * Copyright February 2010 - Paolo Bonzini <pbonzini@redhat.com>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program 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
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 #include "../config.h"
32 #include <sys/types.h>
39 #include <urcu/arch.h>
40 #include <urcu/tls-compat.h>
47 /* hardcoded number of CPUs */
50 #if defined(_syscall0)
51 _syscall0(pid_t
, gettid
)
52 #elif defined(__NR_gettid)
53 static inline pid_t
gettid(void)
55 return syscall(__NR_gettid
);
58 #warning "use pid as tid"
59 static inline pid_t
gettid(void)
65 #ifndef DYNAMIC_LINK_TEST
70 #include <urcu-defer.h>
72 static volatile int test_go
, test_stop
;
74 static unsigned long rduration
;
76 static unsigned long duration
;
78 /* read-side C.S. duration, in loops */
79 static unsigned long wdelay
;
81 static inline void loop_sleep(unsigned long l
)
87 static int verbose_mode
;
89 #define printf_verbose(fmt, args...) \
95 static unsigned int cpu_affinities
[NR_CPUS
];
96 static unsigned int next_aff
= 0;
97 static int use_affinity
= 0;
99 pthread_mutex_t affinity_mutex
= PTHREAD_MUTEX_INITIALIZER
;
101 static void set_affinity(void)
110 #if HAVE_SCHED_SETAFFINITY
111 ret
= pthread_mutex_lock(&affinity_mutex
);
113 perror("Error in pthread mutex lock");
116 cpu
= cpu_affinities
[next_aff
++];
117 ret
= pthread_mutex_unlock(&affinity_mutex
);
119 perror("Error in pthread mutex unlock");
125 #if SCHED_SETAFFINITY_ARGS == 2
126 sched_setaffinity(0, &mask
);
128 sched_setaffinity(0, sizeof(mask
), &mask
);
130 #endif /* HAVE_SCHED_SETAFFINITY */
134 * returns 0 if test should end.
136 static int test_duration_dequeue(void)
141 static int test_duration_enqueue(void)
146 static DEFINE_URCU_TLS(unsigned long long, nr_dequeues
);
147 static DEFINE_URCU_TLS(unsigned long long, nr_enqueues
);
149 static DEFINE_URCU_TLS(unsigned long long, nr_successful_dequeues
);
150 static DEFINE_URCU_TLS(unsigned long long, nr_successful_enqueues
);
152 static unsigned int nr_enqueuers
;
153 static unsigned int nr_dequeuers
;
156 struct cds_lfs_node_rcu list
;
160 static struct cds_lfs_stack_rcu s
;
162 void *thr_enqueuer(void *_count
)
164 unsigned long long *count
= _count
;
166 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
167 "enqueuer", (unsigned long) pthread_self(),
168 (unsigned long) gettid());
172 rcu_register_thread();
180 struct test
*node
= malloc(sizeof(*node
));
183 cds_lfs_node_init_rcu(&node
->list
);
184 /* No rcu read-side is needed for push */
185 cds_lfs_push_rcu(&s
, &node
->list
);
186 URCU_TLS(nr_successful_enqueues
)++;
188 if (caa_unlikely(wdelay
))
191 URCU_TLS(nr_enqueues
)++;
192 if (caa_unlikely(!test_duration_enqueue()))
196 rcu_unregister_thread();
198 count
[0] = URCU_TLS(nr_enqueues
);
199 count
[1] = URCU_TLS(nr_successful_enqueues
);
200 printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
201 "enqueues %llu successful_enqueues %llu\n",
202 (unsigned long) pthread_self(),
203 (unsigned long) gettid(),
204 URCU_TLS(nr_enqueues
), URCU_TLS(nr_successful_enqueues
));
210 void free_node_cb(struct rcu_head
*head
)
213 caa_container_of(head
, struct test
, rcu
);
217 void *thr_dequeuer(void *_count
)
219 unsigned long long *count
= _count
;
222 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
223 "dequeuer", (unsigned long) pthread_self(),
224 (unsigned long) gettid());
228 ret
= rcu_defer_register_thread();
230 printf("Error in rcu_defer_register_thread\n");
233 rcu_register_thread();
241 struct cds_lfs_node_rcu
*snode
;
245 snode
= cds_lfs_pop_rcu(&s
);
246 node
= caa_container_of(snode
, struct test
, list
);
249 call_rcu(&node
->rcu
, free_node_cb
);
250 URCU_TLS(nr_successful_dequeues
)++;
252 URCU_TLS(nr_dequeues
)++;
253 if (caa_unlikely(!test_duration_dequeue()))
255 if (caa_unlikely(rduration
))
256 loop_sleep(rduration
);
259 rcu_unregister_thread();
260 rcu_defer_unregister_thread();
262 printf_verbose("dequeuer thread_end, thread id : %lx, tid %lu, "
263 "dequeues %llu, successful_dequeues %llu\n",
264 (unsigned long) pthread_self(),
265 (unsigned long) gettid(),
266 URCU_TLS(nr_dequeues
), URCU_TLS(nr_successful_dequeues
));
267 count
[0] = URCU_TLS(nr_dequeues
);
268 count
[1] = URCU_TLS(nr_successful_dequeues
);
272 void test_end(struct cds_lfs_stack_rcu
*s
, unsigned long long *nr_dequeues
)
274 struct cds_lfs_node_rcu
*snode
;
277 snode
= cds_lfs_pop_rcu(s
);
281 node
= caa_container_of(snode
, struct test
, list
);
288 void show_usage(int argc
, char **argv
)
290 printf("Usage : %s nr_dequeuers nr_enqueuers duration (s)", argv
[0]);
291 printf(" [-d delay] (enqueuer period (in loops))");
292 printf(" [-c duration] (dequeuer period (in loops))");
293 printf(" [-v] (verbose output)");
294 printf(" [-a cpu#] [-a cpu#]... (affinity)");
298 int main(int argc
, char **argv
)
301 pthread_t
*tid_enqueuer
, *tid_dequeuer
;
303 unsigned long long *count_enqueuer
, *count_dequeuer
;
304 unsigned long long tot_enqueues
= 0, tot_dequeues
= 0;
305 unsigned long long tot_successful_enqueues
= 0,
306 tot_successful_dequeues
= 0;
307 unsigned long long end_dequeues
= 0;
311 show_usage(argc
, argv
);
315 err
= sscanf(argv
[1], "%u", &nr_dequeuers
);
317 show_usage(argc
, argv
);
321 err
= sscanf(argv
[2], "%u", &nr_enqueuers
);
323 show_usage(argc
, argv
);
327 err
= sscanf(argv
[3], "%lu", &duration
);
329 show_usage(argc
, argv
);
333 for (i
= 4; i
< argc
; i
++) {
334 if (argv
[i
][0] != '-')
336 switch (argv
[i
][1]) {
339 show_usage(argc
, argv
);
343 cpu_affinities
[next_aff
++] = a
;
345 printf_verbose("Adding CPU %d affinity\n", a
);
349 show_usage(argc
, argv
);
352 rduration
= atol(argv
[++i
]);
356 show_usage(argc
, argv
);
359 wdelay
= atol(argv
[++i
]);
367 printf_verbose("running test for %lu seconds, %u enqueuers, "
369 duration
, nr_enqueuers
, nr_dequeuers
);
370 printf_verbose("Writer delay : %lu loops.\n", rduration
);
371 printf_verbose("Reader duration : %lu loops.\n", wdelay
);
372 printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
373 "main", (unsigned long) pthread_self(),
374 (unsigned long) gettid());
376 tid_enqueuer
= malloc(sizeof(*tid_enqueuer
) * nr_enqueuers
);
377 tid_dequeuer
= malloc(sizeof(*tid_dequeuer
) * nr_dequeuers
);
378 count_enqueuer
= malloc(2 * sizeof(*count_enqueuer
) * nr_enqueuers
);
379 count_dequeuer
= malloc(2 * sizeof(*count_dequeuer
) * nr_dequeuers
);
380 cds_lfs_init_rcu(&s
);
381 err
= create_all_cpu_call_rcu_data(0);
383 printf("Per-CPU call_rcu() worker threads unavailable. Using default global worker thread.\n");
388 for (i
= 0; i
< nr_enqueuers
; i
++) {
389 err
= pthread_create(&tid_enqueuer
[i
], NULL
, thr_enqueuer
,
390 &count_enqueuer
[2 * i
]);
394 for (i
= 0; i
< nr_dequeuers
; i
++) {
395 err
= pthread_create(&tid_dequeuer
[i
], NULL
, thr_dequeuer
,
396 &count_dequeuer
[2 * i
]);
405 for (i
= 0; i
< duration
; i
++) {
413 for (i
= 0; i
< nr_enqueuers
; i
++) {
414 err
= pthread_join(tid_enqueuer
[i
], &tret
);
417 tot_enqueues
+= count_enqueuer
[2 * i
];
418 tot_successful_enqueues
+= count_enqueuer
[2 * i
+ 1];
420 for (i
= 0; i
< nr_dequeuers
; i
++) {
421 err
= pthread_join(tid_dequeuer
[i
], &tret
);
424 tot_dequeues
+= count_dequeuer
[2 * i
];
425 tot_successful_dequeues
+= count_dequeuer
[2 * i
+ 1];
428 test_end(&s
, &end_dequeues
);
430 printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
431 tot_enqueues
, tot_dequeues
);
432 printf_verbose("total number of successful enqueues : %llu, "
433 "successful dequeues %llu\n",
434 tot_successful_enqueues
, tot_successful_dequeues
);
435 printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
437 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
438 "successful enqueues %12llu successful dequeues %12llu "
439 "end_dequeues %llu nr_ops %12llu\n",
440 argv
[0], duration
, nr_enqueuers
, wdelay
,
441 nr_dequeuers
, rduration
, tot_enqueues
, tot_dequeues
,
442 tot_successful_enqueues
,
443 tot_successful_dequeues
, end_dequeues
,
444 tot_enqueues
+ tot_dequeues
);
445 if (tot_successful_enqueues
!= tot_successful_dequeues
+ end_dequeues
)
446 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
447 "succ. dequeues + end dequeues %llu.\n",
448 tot_successful_enqueues
,
449 tot_successful_dequeues
+ end_dequeues
);
451 free_all_cpu_call_rcu_data();
452 free(count_enqueuer
);
453 free(count_dequeuer
);