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
70 static volatile int test_go
, test_stop
;
72 static unsigned long rduration
;
74 static unsigned long duration
;
76 /* read-side C.S. duration, in loops */
77 static unsigned long wdelay
;
79 static inline void loop_sleep(unsigned long l
)
85 static int verbose_mode
;
87 #define printf_verbose(fmt, args...) \
93 static unsigned int cpu_affinities
[NR_CPUS
];
94 static unsigned int next_aff
= 0;
95 static int use_affinity
= 0;
97 pthread_mutex_t affinity_mutex
= PTHREAD_MUTEX_INITIALIZER
;
99 #ifndef HAVE_CPU_SET_T
100 typedef unsigned long cpu_set_t
;
101 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
102 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
105 static void set_affinity(void)
114 #if HAVE_SCHED_SETAFFINITY
115 ret
= pthread_mutex_lock(&affinity_mutex
);
117 perror("Error in pthread mutex lock");
120 cpu
= cpu_affinities
[next_aff
++];
121 ret
= pthread_mutex_unlock(&affinity_mutex
);
123 perror("Error in pthread mutex unlock");
129 #if SCHED_SETAFFINITY_ARGS == 2
130 sched_setaffinity(0, &mask
);
132 sched_setaffinity(0, sizeof(mask
), &mask
);
134 #endif /* HAVE_SCHED_SETAFFINITY */
138 * returns 0 if test should end.
140 static int test_duration_dequeue(void)
145 static int test_duration_enqueue(void)
150 static unsigned long long __thread nr_dequeues
;
151 static unsigned long long __thread nr_enqueues
;
153 static unsigned long long __thread nr_successful_dequeues
;
154 static unsigned long long __thread nr_successful_enqueues
;
156 static unsigned int nr_enqueuers
;
157 static unsigned int nr_dequeuers
;
159 static struct cds_lfq_queue_rcu q
;
161 void *thr_enqueuer(void *_count
)
163 unsigned long long *count
= _count
;
165 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
166 "enqueuer", pthread_self(), (unsigned long)gettid());
170 rcu_register_thread();
178 struct cds_lfq_node_rcu
*node
= malloc(sizeof(*node
));
181 cds_lfq_node_init_rcu(node
);
183 cds_lfq_enqueue_rcu(&q
, node
);
185 nr_successful_enqueues
++;
187 if (unlikely(wdelay
))
191 if (unlikely(!test_duration_enqueue()))
195 rcu_unregister_thread();
197 count
[0] = nr_enqueues
;
198 count
[1] = nr_successful_enqueues
;
199 printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
200 "enqueues %llu successful_enqueues %llu\n",
201 pthread_self(), (unsigned long)gettid(), nr_enqueues
,
202 nr_successful_enqueues
);
207 static void rcu_free_node(struct rcu_head
*head
)
209 struct cds_lfq_node_rcu
*node
=
210 caa_container_of(head
, struct cds_lfq_node_rcu
, rcu_head
);
214 static void ref_release_node(struct urcu_ref
*ref
)
216 struct cds_lfq_node_rcu
*node
=
217 caa_container_of(ref
, struct cds_lfq_node_rcu
, ref
);
218 call_rcu(&node
->rcu_head
, rcu_free_node
);
221 void *thr_dequeuer(void *_count
)
223 unsigned long long *count
= _count
;
226 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
227 "dequeuer", pthread_self(), (unsigned long)gettid());
231 rcu_register_thread();
239 struct cds_lfq_node_rcu
*node
;
242 node
= cds_lfq_dequeue_rcu(&q
);
246 urcu_ref_put(&node
->ref
, ref_release_node
);
247 nr_successful_dequeues
++;
251 if (unlikely(!test_duration_dequeue()))
253 if (unlikely(rduration
))
254 loop_sleep(rduration
);
257 rcu_unregister_thread();
258 printf_verbose("dequeuer thread_end, thread id : %lx, tid %lu, "
259 "dequeues %llu, successful_dequeues %llu\n",
260 pthread_self(), (unsigned long)gettid(), nr_dequeues
,
261 nr_successful_dequeues
);
262 count
[0] = nr_dequeues
;
263 count
[1] = nr_successful_dequeues
;
267 static void release_node(struct urcu_ref
*ref
)
269 struct cds_lfq_node_rcu
*node
= caa_container_of(ref
, struct cds_lfq_node_rcu
, ref
);
273 void test_end(struct cds_lfq_queue_rcu
*q
, unsigned long long *nr_dequeues
)
275 struct cds_lfq_node_rcu
*node
;
279 node
= cds_lfq_dequeue_rcu(q
);
282 urcu_ref_put(&node
->ref
, release_node
);
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", pthread_self(), (unsigned long)gettid());
375 tid_enqueuer
= malloc(sizeof(*tid_enqueuer
) * nr_enqueuers
);
376 tid_dequeuer
= malloc(sizeof(*tid_dequeuer
) * nr_dequeuers
);
377 count_enqueuer
= malloc(2 * sizeof(*count_enqueuer
) * nr_enqueuers
);
378 count_dequeuer
= malloc(2 * sizeof(*count_dequeuer
) * nr_dequeuers
);
379 cds_lfq_init_rcu(&q
, ref_release_node
);
383 for (i
= 0; i
< nr_enqueuers
; i
++) {
384 err
= pthread_create(&tid_enqueuer
[i
], NULL
, thr_enqueuer
,
385 &count_enqueuer
[2 * i
]);
389 for (i
= 0; i
< nr_dequeuers
; i
++) {
390 err
= pthread_create(&tid_dequeuer
[i
], NULL
, thr_dequeuer
,
391 &count_dequeuer
[2 * i
]);
400 for (i
= 0; i
< duration
; i
++) {
408 for (i
= 0; i
< nr_enqueuers
; i
++) {
409 err
= pthread_join(tid_enqueuer
[i
], &tret
);
412 tot_enqueues
+= count_enqueuer
[2 * i
];
413 tot_successful_enqueues
+= count_enqueuer
[2 * i
+ 1];
415 for (i
= 0; i
< nr_dequeuers
; i
++) {
416 err
= pthread_join(tid_dequeuer
[i
], &tret
);
419 tot_dequeues
+= count_dequeuer
[2 * i
];
420 tot_successful_dequeues
+= count_dequeuer
[2 * i
+ 1];
423 test_end(&q
, &end_dequeues
);
425 printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
426 tot_enqueues
, tot_dequeues
);
427 printf_verbose("total number of successful enqueues : %llu, "
428 "successful dequeues %llu\n",
429 tot_successful_enqueues
, tot_successful_dequeues
);
430 printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
432 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
433 "successful enqueues %12llu successful dequeues %12llu "
434 "end_dequeues %llu nr_ops %12llu\n",
435 argv
[0], duration
, nr_enqueuers
, wdelay
,
436 nr_dequeuers
, rduration
, tot_enqueues
, tot_dequeues
,
437 tot_successful_enqueues
,
438 tot_successful_dequeues
, end_dequeues
,
439 tot_enqueues
+ tot_dequeues
);
440 if (tot_successful_enqueues
!= tot_successful_dequeues
+ end_dequeues
)
441 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
442 "succ. dequeues + end dequeues %llu.\n",
443 tot_successful_enqueues
,
444 tot_successful_dequeues
+ end_dequeues
);
446 free(count_enqueuer
);
447 free(count_dequeuer
);