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>
46 /* hardcoded number of CPUs */
49 #if defined(_syscall0)
50 _syscall0(pid_t
, gettid
)
51 #elif defined(__NR_gettid)
52 static inline pid_t
gettid(void)
54 return syscall(__NR_gettid
);
57 #warning "use pid as tid"
58 static inline pid_t
gettid(void)
64 #ifndef DYNAMIC_LINK_TEST
69 #include <urcu-defer.h>
71 static volatile int test_go
, test_stop
;
73 static unsigned long rduration
;
75 static unsigned long duration
;
77 /* read-side C.S. duration, in loops */
78 static unsigned long wdelay
;
80 static inline void loop_sleep(unsigned long l
)
86 static int verbose_mode
;
88 #define printf_verbose(fmt, args...) \
94 static unsigned int cpu_affinities
[NR_CPUS
];
95 static unsigned int next_aff
= 0;
96 static int use_affinity
= 0;
98 pthread_mutex_t affinity_mutex
= PTHREAD_MUTEX_INITIALIZER
;
100 #ifndef HAVE_CPU_SET_T
101 typedef unsigned long cpu_set_t
;
102 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
103 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
106 static void set_affinity(void)
115 #if HAVE_SCHED_SETAFFINITY
116 ret
= pthread_mutex_lock(&affinity_mutex
);
118 perror("Error in pthread mutex lock");
121 cpu
= cpu_affinities
[next_aff
++];
122 ret
= pthread_mutex_unlock(&affinity_mutex
);
124 perror("Error in pthread mutex unlock");
130 #if SCHED_SETAFFINITY_ARGS == 2
131 sched_setaffinity(0, &mask
);
133 sched_setaffinity(0, sizeof(mask
), &mask
);
135 #endif /* HAVE_SCHED_SETAFFINITY */
139 * returns 0 if test should end.
141 static int test_duration_dequeue(void)
146 static int test_duration_enqueue(void)
151 static unsigned long long __thread nr_dequeues
;
152 static unsigned long long __thread nr_enqueues
;
154 static unsigned long long __thread nr_successful_dequeues
;
155 static unsigned long long __thread nr_successful_enqueues
;
157 static unsigned int nr_enqueuers
;
158 static unsigned int nr_dequeuers
;
160 static struct cds_lfq_queue_rcu q
;
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", pthread_self(), (unsigned long)gettid());
171 rcu_register_thread();
179 struct cds_lfq_node_rcu
*node
= malloc(sizeof(*node
));
182 cds_lfq_node_init_rcu(node
);
183 cds_lfq_enqueue_rcu(&q
, node
);
184 nr_successful_enqueues
++;
186 if (unlikely(wdelay
))
190 if (unlikely(!test_duration_enqueue()))
194 rcu_unregister_thread();
196 count
[0] = nr_enqueues
;
197 count
[1] = nr_successful_enqueues
;
198 printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
199 "enqueues %llu successful_enqueues %llu\n",
200 pthread_self(), (unsigned long)gettid(), nr_enqueues
,
201 nr_successful_enqueues
);
206 void *thr_dequeuer(void *_count
)
208 unsigned long long *count
= _count
;
211 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
212 "dequeuer", pthread_self(), (unsigned long)gettid());
216 ret
= rcu_defer_register_thread();
218 printf("Error in rcu_defer_register_thread\n");
221 rcu_register_thread();
229 struct cds_lfq_node_rcu
*node
;
231 node
= cds_lfq_dequeue_rcu(&q
);
233 defer_rcu(free
, node
);
234 nr_successful_dequeues
++;
238 if (unlikely(!test_duration_dequeue()))
240 if (unlikely(rduration
))
241 loop_sleep(rduration
);
244 rcu_unregister_thread();
245 rcu_defer_unregister_thread();
246 printf_verbose("dequeuer thread_end, thread id : %lx, tid %lu, "
247 "dequeues %llu, successful_dequeues %llu\n",
248 pthread_self(), (unsigned long)gettid(), nr_dequeues
,
249 nr_successful_dequeues
);
250 count
[0] = nr_dequeues
;
251 count
[1] = nr_successful_dequeues
;
255 void test_end(struct cds_lfq_queue_rcu
*q
, unsigned long long *nr_dequeues
)
257 struct cds_lfq_node_rcu
*node
;
260 node
= cds_lfq_dequeue_rcu(q
);
262 free(node
); /* no more concurrent access */
268 void show_usage(int argc
, char **argv
)
270 printf("Usage : %s nr_dequeuers nr_enqueuers duration (s)", argv
[0]);
271 printf(" [-d delay] (enqueuer period (in loops))");
272 printf(" [-c duration] (dequeuer period (in loops))");
273 printf(" [-v] (verbose output)");
274 printf(" [-a cpu#] [-a cpu#]... (affinity)");
278 int main(int argc
, char **argv
)
281 pthread_t
*tid_enqueuer
, *tid_dequeuer
;
283 unsigned long long *count_enqueuer
, *count_dequeuer
;
284 unsigned long long tot_enqueues
= 0, tot_dequeues
= 0;
285 unsigned long long tot_successful_enqueues
= 0,
286 tot_successful_dequeues
= 0;
287 unsigned long long end_dequeues
= 0;
291 show_usage(argc
, argv
);
295 err
= sscanf(argv
[1], "%u", &nr_dequeuers
);
297 show_usage(argc
, argv
);
301 err
= sscanf(argv
[2], "%u", &nr_enqueuers
);
303 show_usage(argc
, argv
);
307 err
= sscanf(argv
[3], "%lu", &duration
);
309 show_usage(argc
, argv
);
313 for (i
= 4; i
< argc
; i
++) {
314 if (argv
[i
][0] != '-')
316 switch (argv
[i
][1]) {
319 show_usage(argc
, argv
);
323 cpu_affinities
[next_aff
++] = a
;
325 printf_verbose("Adding CPU %d affinity\n", a
);
329 show_usage(argc
, argv
);
332 rduration
= atol(argv
[++i
]);
336 show_usage(argc
, argv
);
339 wdelay
= atol(argv
[++i
]);
347 printf_verbose("running test for %lu seconds, %u enqueuers, "
349 duration
, nr_enqueuers
, nr_dequeuers
);
350 printf_verbose("Writer delay : %lu loops.\n", rduration
);
351 printf_verbose("Reader duration : %lu loops.\n", wdelay
);
352 printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
353 "main", pthread_self(), (unsigned long)gettid());
355 tid_enqueuer
= malloc(sizeof(*tid_enqueuer
) * nr_enqueuers
);
356 tid_dequeuer
= malloc(sizeof(*tid_dequeuer
) * nr_dequeuers
);
357 count_enqueuer
= malloc(2 * sizeof(*count_enqueuer
) * nr_enqueuers
);
358 count_dequeuer
= malloc(2 * sizeof(*count_dequeuer
) * nr_dequeuers
);
359 cds_lfq_init_rcu(&q
);
363 for (i
= 0; i
< nr_enqueuers
; i
++) {
364 err
= pthread_create(&tid_enqueuer
[i
], NULL
, thr_enqueuer
,
365 &count_enqueuer
[2 * i
]);
369 for (i
= 0; i
< nr_dequeuers
; i
++) {
370 err
= pthread_create(&tid_dequeuer
[i
], NULL
, thr_dequeuer
,
371 &count_dequeuer
[2 * i
]);
380 for (i
= 0; i
< duration
; i
++) {
388 for (i
= 0; i
< nr_enqueuers
; i
++) {
389 err
= pthread_join(tid_enqueuer
[i
], &tret
);
392 tot_enqueues
+= count_enqueuer
[2 * i
];
393 tot_successful_enqueues
+= count_enqueuer
[2 * i
+ 1];
395 for (i
= 0; i
< nr_dequeuers
; i
++) {
396 err
= pthread_join(tid_dequeuer
[i
], &tret
);
399 tot_dequeues
+= count_dequeuer
[2 * i
];
400 tot_successful_dequeues
+= count_dequeuer
[2 * i
+ 1];
403 test_end(&q
, &end_dequeues
);
404 err
= cds_lfq_destroy_rcu(&q
);
407 printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
408 tot_enqueues
, tot_dequeues
);
409 printf_verbose("total number of successful enqueues : %llu, "
410 "successful dequeues %llu\n",
411 tot_successful_enqueues
, tot_successful_dequeues
);
412 printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
414 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
415 "successful enqueues %12llu successful dequeues %12llu "
416 "end_dequeues %llu nr_ops %12llu\n",
417 argv
[0], duration
, nr_enqueuers
, wdelay
,
418 nr_dequeuers
, rduration
, tot_enqueues
, tot_dequeues
,
419 tot_successful_enqueues
,
420 tot_successful_dequeues
, end_dequeues
,
421 tot_enqueues
+ tot_dequeues
);
422 if (tot_successful_enqueues
!= tot_successful_dequeues
+ end_dequeues
)
423 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
424 "succ. dequeues + end dequeues %llu.\n",
425 tot_successful_enqueues
,
426 tot_successful_dequeues
+ end_dequeues
);
428 free(count_enqueuer
);
429 free(count_dequeuer
);