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
);
180 cds_lfq_enqueue_rcu(&q
, node
);
181 nr_successful_enqueues
++;
183 if (unlikely(wdelay
))
187 if (unlikely(!test_duration_enqueue()))
191 rcu_unregister_thread();
193 count
[0] = nr_enqueues
;
194 count
[1] = nr_successful_enqueues
;
195 printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
196 "enqueues %llu successful_enqueues %llu\n",
197 pthread_self(), (unsigned long)gettid(), nr_enqueues
,
198 nr_successful_enqueues
);
203 static void rcu_release_node(struct urcu_ref
*ref
)
205 struct cds_lfq_node_rcu
*node
= caa_container_of(ref
, struct cds_lfq_node_rcu
, ref
);
206 defer_rcu(free
, node
);
211 void *thr_dequeuer(void *_count
)
213 unsigned long long *count
= _count
;
216 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
217 "dequeuer", pthread_self(), (unsigned long)gettid());
221 ret
= rcu_defer_register_thread();
223 printf("Error in rcu_defer_register_thread\n");
226 rcu_register_thread();
234 struct cds_lfq_node_rcu
*node
= cds_lfq_dequeue_rcu(&q
,
238 urcu_ref_put(&node
->ref
, rcu_release_node
);
239 nr_successful_dequeues
++;
243 if (unlikely(!test_duration_dequeue()))
245 if (unlikely(rduration
))
246 loop_sleep(rduration
);
249 rcu_unregister_thread();
250 rcu_defer_unregister_thread();
252 printf_verbose("dequeuer thread_end, thread id : %lx, tid %lu, "
253 "dequeues %llu, successful_dequeues %llu\n",
254 pthread_self(), (unsigned long)gettid(), nr_dequeues
,
255 nr_successful_dequeues
);
256 count
[0] = nr_dequeues
;
257 count
[1] = nr_successful_dequeues
;
261 static void release_node(struct urcu_ref
*ref
)
263 struct cds_lfq_node_rcu
*node
= caa_container_of(ref
, struct cds_lfq_node_rcu
, ref
);
267 void test_end(struct cds_lfq_queue_rcu
*q
, unsigned long long *nr_dequeues
)
269 struct cds_lfq_node_rcu
*node
;
272 node
= cds_lfq_dequeue_rcu(q
, release_node
);
274 urcu_ref_put(&node
->ref
, release_node
);
280 void show_usage(int argc
, char **argv
)
282 printf("Usage : %s nr_dequeuers nr_enqueuers duration (s)", argv
[0]);
283 printf(" [-d delay] (enqueuer period (in loops))");
284 printf(" [-c duration] (dequeuer period (in loops))");
285 printf(" [-v] (verbose output)");
286 printf(" [-a cpu#] [-a cpu#]... (affinity)");
290 int main(int argc
, char **argv
)
293 pthread_t
*tid_enqueuer
, *tid_dequeuer
;
295 unsigned long long *count_enqueuer
, *count_dequeuer
;
296 unsigned long long tot_enqueues
= 0, tot_dequeues
= 0;
297 unsigned long long tot_successful_enqueues
= 0,
298 tot_successful_dequeues
= 0;
299 unsigned long long end_dequeues
= 0;
303 show_usage(argc
, argv
);
307 err
= sscanf(argv
[1], "%u", &nr_dequeuers
);
309 show_usage(argc
, argv
);
313 err
= sscanf(argv
[2], "%u", &nr_enqueuers
);
315 show_usage(argc
, argv
);
319 err
= sscanf(argv
[3], "%lu", &duration
);
321 show_usage(argc
, argv
);
325 for (i
= 4; i
< argc
; i
++) {
326 if (argv
[i
][0] != '-')
328 switch (argv
[i
][1]) {
331 show_usage(argc
, argv
);
335 cpu_affinities
[next_aff
++] = a
;
337 printf_verbose("Adding CPU %d affinity\n", a
);
341 show_usage(argc
, argv
);
344 rduration
= atol(argv
[++i
]);
348 show_usage(argc
, argv
);
351 wdelay
= atol(argv
[++i
]);
359 printf_verbose("running test for %lu seconds, %u enqueuers, "
361 duration
, nr_enqueuers
, nr_dequeuers
);
362 printf_verbose("Writer delay : %lu loops.\n", rduration
);
363 printf_verbose("Reader duration : %lu loops.\n", wdelay
);
364 printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
365 "main", pthread_self(), (unsigned long)gettid());
367 tid_enqueuer
= malloc(sizeof(*tid_enqueuer
) * nr_enqueuers
);
368 tid_dequeuer
= malloc(sizeof(*tid_dequeuer
) * nr_dequeuers
);
369 count_enqueuer
= malloc(2 * sizeof(*count_enqueuer
) * nr_enqueuers
);
370 count_dequeuer
= malloc(2 * sizeof(*count_dequeuer
) * nr_dequeuers
);
371 cds_lfq_init_rcu(&q
);
375 for (i
= 0; i
< nr_enqueuers
; i
++) {
376 err
= pthread_create(&tid_enqueuer
[i
], NULL
, thr_enqueuer
,
377 &count_enqueuer
[2 * i
]);
381 for (i
= 0; i
< nr_dequeuers
; i
++) {
382 err
= pthread_create(&tid_dequeuer
[i
], NULL
, thr_dequeuer
,
383 &count_dequeuer
[2 * i
]);
392 for (i
= 0; i
< duration
; i
++) {
400 for (i
= 0; i
< nr_enqueuers
; i
++) {
401 err
= pthread_join(tid_enqueuer
[i
], &tret
);
404 tot_enqueues
+= count_enqueuer
[2 * i
];
405 tot_successful_enqueues
+= count_enqueuer
[2 * i
+ 1];
407 for (i
= 0; i
< nr_dequeuers
; i
++) {
408 err
= pthread_join(tid_dequeuer
[i
], &tret
);
411 tot_dequeues
+= count_dequeuer
[2 * i
];
412 tot_successful_dequeues
+= count_dequeuer
[2 * i
+ 1];
415 test_end(&q
, &end_dequeues
);
417 printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
418 tot_enqueues
, tot_dequeues
);
419 printf_verbose("total number of successful enqueues : %llu, "
420 "successful dequeues %llu\n",
421 tot_successful_enqueues
, tot_successful_dequeues
);
422 printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
424 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
425 "successful enqueues %12llu successful dequeues %12llu "
426 "end_dequeues %llu nr_ops %12llu\n",
427 argv
[0], duration
, nr_enqueuers
, wdelay
,
428 nr_dequeuers
, rduration
, tot_enqueues
, tot_dequeues
,
429 tot_successful_enqueues
,
430 tot_successful_dequeues
, end_dequeues
,
431 tot_enqueues
+ tot_dequeues
);
432 if (tot_successful_enqueues
!= tot_successful_dequeues
+ end_dequeues
)
433 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
434 "succ. dequeues + end dequeues %llu.\n",
435 tot_successful_enqueues
,
436 tot_successful_dequeues
+ end_dequeues
);
438 free(count_enqueuer
);
439 free(count_dequeuer
);