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>
37 #include <sys/syscall.h>
41 #include <urcu/arch.h>
43 /* hardcoded number of CPUs */
46 #if defined(_syscall0)
47 _syscall0(pid_t
, gettid
)
48 #elif defined(__NR_gettid)
49 static inline pid_t
gettid(void)
51 return syscall(__NR_gettid
);
54 #warning "use pid as tid"
55 static inline pid_t
gettid(void)
61 #ifndef DYNAMIC_LINK_TEST
65 #include <urcu/rculfqueue.h>
66 #include <urcu-defer.h>
68 static volatile int test_go
, test_stop
;
70 static unsigned long rduration
;
72 static unsigned long duration
;
74 /* read-side C.S. duration, in loops */
75 static unsigned long wdelay
;
77 static inline void loop_sleep(unsigned long l
)
83 static int verbose_mode
;
85 #define printf_verbose(fmt, args...) \
91 static unsigned int cpu_affinities
[NR_CPUS
];
92 static unsigned int next_aff
= 0;
93 static int use_affinity
= 0;
95 pthread_mutex_t affinity_mutex
= PTHREAD_MUTEX_INITIALIZER
;
97 #ifndef HAVE_CPU_SET_T
98 typedef unsigned long cpu_set_t
;
99 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
100 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
103 static void set_affinity(void)
112 #if HAVE_SCHED_SETAFFINITY
113 ret
= pthread_mutex_lock(&affinity_mutex
);
115 perror("Error in pthread mutex lock");
118 cpu
= cpu_affinities
[next_aff
++];
119 ret
= pthread_mutex_unlock(&affinity_mutex
);
121 perror("Error in pthread mutex unlock");
127 #if SCHED_SETAFFINITY_ARGS == 2
128 sched_setaffinity(0, &mask
);
130 sched_setaffinity(0, sizeof(mask
), &mask
);
132 #endif /* HAVE_SCHED_SETAFFINITY */
136 * returns 0 if test should end.
138 static int test_duration_dequeue(void)
143 static int test_duration_enqueue(void)
148 static unsigned long long __thread nr_dequeues
;
149 static unsigned long long __thread nr_enqueues
;
151 static unsigned long long __thread nr_successful_dequeues
;
152 static unsigned long long __thread nr_successful_enqueues
;
154 static unsigned int nr_enqueuers
;
155 static unsigned int nr_dequeuers
;
157 static struct cds_lfq_queue_rcu q
;
159 void *thr_enqueuer(void *_count
)
161 unsigned long long *count
= _count
;
163 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
164 "enqueuer", pthread_self(), (unsigned long)gettid());
168 rcu_register_thread();
176 struct cds_lfq_node_rcu
*node
= malloc(sizeof(*node
));
179 cds_lfq_node_init_rcu(node
);
181 cds_lfq_enqueue_rcu(&q
, node
);
183 nr_successful_enqueues
++;
185 if (unlikely(wdelay
))
189 if (unlikely(!test_duration_enqueue()))
193 rcu_unregister_thread();
195 count
[0] = nr_enqueues
;
196 count
[1] = nr_successful_enqueues
;
197 printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
198 "enqueues %llu successful_enqueues %llu\n",
199 pthread_self(), (unsigned long)gettid(), nr_enqueues
,
200 nr_successful_enqueues
);
205 static void rcu_free_node(struct rcu_head
*head
)
207 struct cds_lfq_node_rcu
*node
=
208 caa_container_of(head
, struct cds_lfq_node_rcu
, rcu_head
);
212 static void ref_release_node(struct urcu_ref
*ref
)
214 struct cds_lfq_node_rcu
*node
=
215 caa_container_of(ref
, struct cds_lfq_node_rcu
, ref
);
216 call_rcu(&node
->rcu_head
, rcu_free_node
);
219 void *thr_dequeuer(void *_count
)
221 unsigned long long *count
= _count
;
224 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
225 "dequeuer", pthread_self(), (unsigned long)gettid());
229 ret
= rcu_defer_register_thread();
231 printf("Error in rcu_defer_register_thread\n");
234 rcu_register_thread();
242 struct cds_lfq_node_rcu
*node
;
245 node
= cds_lfq_dequeue_rcu(&q
);
249 urcu_ref_put(&node
->ref
, ref_release_node
);
250 nr_successful_dequeues
++;
254 if (unlikely(!test_duration_dequeue()))
256 if (unlikely(rduration
))
257 loop_sleep(rduration
);
260 rcu_unregister_thread();
261 rcu_defer_unregister_thread();
263 printf_verbose("dequeuer thread_end, thread id : %lx, tid %lu, "
264 "dequeues %llu, successful_dequeues %llu\n",
265 pthread_self(), (unsigned long)gettid(), nr_dequeues
,
266 nr_successful_dequeues
);
267 count
[0] = nr_dequeues
;
268 count
[1] = nr_successful_dequeues
;
272 static void release_node(struct urcu_ref
*ref
)
274 struct cds_lfq_node_rcu
*node
= caa_container_of(ref
, struct cds_lfq_node_rcu
, ref
);
278 void test_end(struct cds_lfq_queue_rcu
*q
, unsigned long long *nr_dequeues
)
280 struct cds_lfq_node_rcu
*node
;
284 node
= cds_lfq_dequeue_rcu(q
);
287 urcu_ref_put(&node
->ref
, release_node
);
293 void show_usage(int argc
, char **argv
)
295 printf("Usage : %s nr_dequeuers nr_enqueuers duration (s)", argv
[0]);
296 printf(" [-d delay] (enqueuer period (in loops))");
297 printf(" [-c duration] (dequeuer period (in loops))");
298 printf(" [-v] (verbose output)");
299 printf(" [-a cpu#] [-a cpu#]... (affinity)");
303 int main(int argc
, char **argv
)
306 pthread_t
*tid_enqueuer
, *tid_dequeuer
;
308 unsigned long long *count_enqueuer
, *count_dequeuer
;
309 unsigned long long tot_enqueues
= 0, tot_dequeues
= 0;
310 unsigned long long tot_successful_enqueues
= 0,
311 tot_successful_dequeues
= 0;
312 unsigned long long end_dequeues
= 0;
316 show_usage(argc
, argv
);
320 err
= sscanf(argv
[1], "%u", &nr_dequeuers
);
322 show_usage(argc
, argv
);
326 err
= sscanf(argv
[2], "%u", &nr_enqueuers
);
328 show_usage(argc
, argv
);
332 err
= sscanf(argv
[3], "%lu", &duration
);
334 show_usage(argc
, argv
);
338 for (i
= 4; i
< argc
; i
++) {
339 if (argv
[i
][0] != '-')
341 switch (argv
[i
][1]) {
344 show_usage(argc
, argv
);
348 cpu_affinities
[next_aff
++] = a
;
350 printf_verbose("Adding CPU %d affinity\n", a
);
354 show_usage(argc
, argv
);
357 rduration
= atol(argv
[++i
]);
361 show_usage(argc
, argv
);
364 wdelay
= atol(argv
[++i
]);
372 printf_verbose("running test for %lu seconds, %u enqueuers, "
374 duration
, nr_enqueuers
, nr_dequeuers
);
375 printf_verbose("Writer delay : %lu loops.\n", rduration
);
376 printf_verbose("Reader duration : %lu loops.\n", wdelay
);
377 printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
378 "main", pthread_self(), (unsigned long)gettid());
380 tid_enqueuer
= malloc(sizeof(*tid_enqueuer
) * nr_enqueuers
);
381 tid_dequeuer
= malloc(sizeof(*tid_dequeuer
) * nr_dequeuers
);
382 count_enqueuer
= malloc(2 * sizeof(*count_enqueuer
) * nr_enqueuers
);
383 count_dequeuer
= malloc(2 * sizeof(*count_dequeuer
) * nr_dequeuers
);
384 cds_lfq_init_rcu(&q
, ref_release_node
);
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(&q
, &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(count_enqueuer
);
452 free(count_dequeuer
);