4 * Userspace RCU library - example RCU-based lock-free queue
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>
40 #include <urcu/arch.h>
41 #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 #ifndef HAVE_CPU_SET_T
102 typedef unsigned long cpu_set_t
;
103 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
104 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
107 static void set_affinity(void)
116 #if HAVE_SCHED_SETAFFINITY
117 ret
= pthread_mutex_lock(&affinity_mutex
);
119 perror("Error in pthread mutex lock");
122 cpu
= cpu_affinities
[next_aff
++];
123 ret
= pthread_mutex_unlock(&affinity_mutex
);
125 perror("Error in pthread mutex unlock");
131 #if SCHED_SETAFFINITY_ARGS == 2
132 sched_setaffinity(0, &mask
);
134 sched_setaffinity(0, sizeof(mask
), &mask
);
136 #endif /* HAVE_SCHED_SETAFFINITY */
140 * returns 0 if test should end.
142 static int test_duration_dequeue(void)
147 static int test_duration_enqueue(void)
152 static DEFINE_URCU_TLS(unsigned long long, nr_dequeues
);
153 static DEFINE_URCU_TLS(unsigned long long, nr_enqueues
);
155 static DEFINE_URCU_TLS(unsigned long long, nr_successful_dequeues
);
156 static DEFINE_URCU_TLS(unsigned long long, nr_successful_enqueues
);
158 static unsigned int nr_enqueuers
;
159 static unsigned int nr_dequeuers
;
162 struct cds_lfq_node_rcu list
;
166 static struct cds_lfq_queue_rcu q
;
168 void *thr_enqueuer(void *_count
)
170 unsigned long long *count
= _count
;
172 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
173 "enqueuer", (unsigned long) pthread_self(),
174 (unsigned long) gettid());
178 rcu_register_thread();
186 struct test
*node
= malloc(sizeof(*node
));
189 cds_lfq_node_init_rcu(&node
->list
);
191 cds_lfq_enqueue_rcu(&q
, &node
->list
);
193 URCU_TLS(nr_successful_enqueues
)++;
195 if (caa_unlikely(wdelay
))
198 URCU_TLS(nr_enqueues
)++;
199 if (caa_unlikely(!test_duration_enqueue()))
203 rcu_unregister_thread();
205 count
[0] = URCU_TLS(nr_enqueues
);
206 count
[1] = URCU_TLS(nr_successful_enqueues
);
207 printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
208 "enqueues %llu successful_enqueues %llu\n",
210 (unsigned long) gettid(),
211 URCU_TLS(nr_enqueues
), URCU_TLS(nr_successful_enqueues
));
217 void free_node_cb(struct rcu_head
*head
)
220 caa_container_of(head
, struct test
, rcu
);
224 void *thr_dequeuer(void *_count
)
226 unsigned long long *count
= _count
;
229 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
230 "dequeuer", (unsigned long) pthread_self(),
231 (unsigned long) gettid());
235 ret
= rcu_defer_register_thread();
237 printf("Error in rcu_defer_register_thread\n");
240 rcu_register_thread();
248 struct cds_lfq_node_rcu
*qnode
;
252 qnode
= cds_lfq_dequeue_rcu(&q
);
253 node
= caa_container_of(qnode
, struct test
, list
);
257 call_rcu(&node
->rcu
, free_node_cb
);
258 URCU_TLS(nr_successful_dequeues
)++;
261 URCU_TLS(nr_dequeues
)++;
262 if (caa_unlikely(!test_duration_dequeue()))
264 if (caa_unlikely(rduration
))
265 loop_sleep(rduration
);
268 rcu_unregister_thread();
269 rcu_defer_unregister_thread();
270 printf_verbose("dequeuer thread_end, thread id : %lx, tid %lu, "
271 "dequeues %llu, successful_dequeues %llu\n",
273 (unsigned long) gettid(),
274 URCU_TLS(nr_dequeues
), URCU_TLS(nr_successful_dequeues
));
275 count
[0] = URCU_TLS(nr_dequeues
);
276 count
[1] = URCU_TLS(nr_successful_dequeues
);
280 void test_end(struct cds_lfq_queue_rcu
*q
, unsigned long long *nr_dequeues
)
282 struct cds_lfq_node_rcu
*snode
;
285 snode
= cds_lfq_dequeue_rcu(q
);
289 node
= caa_container_of(snode
, struct test
, list
);
290 free(node
); /* no more concurrent access */
296 void show_usage(int argc
, char **argv
)
298 printf("Usage : %s nr_dequeuers nr_enqueuers duration (s)", argv
[0]);
299 printf(" [-d delay] (enqueuer period (in loops))");
300 printf(" [-c duration] (dequeuer period (in loops))");
301 printf(" [-v] (verbose output)");
302 printf(" [-a cpu#] [-a cpu#]... (affinity)");
306 int main(int argc
, char **argv
)
309 pthread_t
*tid_enqueuer
, *tid_dequeuer
;
311 unsigned long long *count_enqueuer
, *count_dequeuer
;
312 unsigned long long tot_enqueues
= 0, tot_dequeues
= 0;
313 unsigned long long tot_successful_enqueues
= 0,
314 tot_successful_dequeues
= 0;
315 unsigned long long end_dequeues
= 0;
319 show_usage(argc
, argv
);
323 err
= sscanf(argv
[1], "%u", &nr_dequeuers
);
325 show_usage(argc
, argv
);
329 err
= sscanf(argv
[2], "%u", &nr_enqueuers
);
331 show_usage(argc
, argv
);
335 err
= sscanf(argv
[3], "%lu", &duration
);
337 show_usage(argc
, argv
);
341 for (i
= 4; i
< argc
; i
++) {
342 if (argv
[i
][0] != '-')
344 switch (argv
[i
][1]) {
347 show_usage(argc
, argv
);
351 cpu_affinities
[next_aff
++] = a
;
353 printf_verbose("Adding CPU %d affinity\n", a
);
357 show_usage(argc
, argv
);
360 rduration
= atol(argv
[++i
]);
364 show_usage(argc
, argv
);
367 wdelay
= atol(argv
[++i
]);
375 printf_verbose("running test for %lu seconds, %u enqueuers, "
377 duration
, nr_enqueuers
, nr_dequeuers
);
378 printf_verbose("Writer delay : %lu loops.\n", rduration
);
379 printf_verbose("Reader duration : %lu loops.\n", wdelay
);
380 printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
381 "main", (unsigned long) pthread_self(),
382 (unsigned long) gettid());
384 tid_enqueuer
= malloc(sizeof(*tid_enqueuer
) * nr_enqueuers
);
385 tid_dequeuer
= malloc(sizeof(*tid_dequeuer
) * nr_dequeuers
);
386 count_enqueuer
= malloc(2 * sizeof(*count_enqueuer
) * nr_enqueuers
);
387 count_dequeuer
= malloc(2 * sizeof(*count_dequeuer
) * nr_dequeuers
);
388 cds_lfq_init_rcu(&q
, call_rcu
);
389 err
= create_all_cpu_call_rcu_data(0);
391 printf("Per-CPU call_rcu() worker threads unavailable. Using default global worker thread.\n");
396 for (i
= 0; i
< nr_enqueuers
; i
++) {
397 err
= pthread_create(&tid_enqueuer
[i
], NULL
, thr_enqueuer
,
398 &count_enqueuer
[2 * i
]);
402 for (i
= 0; i
< nr_dequeuers
; i
++) {
403 err
= pthread_create(&tid_dequeuer
[i
], NULL
, thr_dequeuer
,
404 &count_dequeuer
[2 * i
]);
413 for (i
= 0; i
< duration
; i
++) {
421 for (i
= 0; i
< nr_enqueuers
; i
++) {
422 err
= pthread_join(tid_enqueuer
[i
], &tret
);
425 tot_enqueues
+= count_enqueuer
[2 * i
];
426 tot_successful_enqueues
+= count_enqueuer
[2 * i
+ 1];
428 for (i
= 0; i
< nr_dequeuers
; i
++) {
429 err
= pthread_join(tid_dequeuer
[i
], &tret
);
432 tot_dequeues
+= count_dequeuer
[2 * i
];
433 tot_successful_dequeues
+= count_dequeuer
[2 * i
+ 1];
436 test_end(&q
, &end_dequeues
);
437 err
= cds_lfq_destroy_rcu(&q
);
440 printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
441 tot_enqueues
, tot_dequeues
);
442 printf_verbose("total number of successful enqueues : %llu, "
443 "successful dequeues %llu\n",
444 tot_successful_enqueues
, tot_successful_dequeues
);
445 printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
447 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
448 "successful enqueues %12llu successful dequeues %12llu "
449 "end_dequeues %llu nr_ops %12llu\n",
450 argv
[0], duration
, nr_enqueuers
, wdelay
,
451 nr_dequeuers
, rduration
, tot_enqueues
, tot_dequeues
,
452 tot_successful_enqueues
,
453 tot_successful_dequeues
, end_dequeues
,
454 tot_enqueues
+ tot_dequeues
);
455 if (tot_successful_enqueues
!= tot_successful_dequeues
+ end_dequeues
)
456 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
457 "succ. dequeues + end dequeues %llu.\n",
458 tot_successful_enqueues
,
459 tot_successful_dequeues
+ end_dequeues
);
461 free_all_cpu_call_rcu_data();
462 free(count_enqueuer
);
463 free(count_dequeuer
);