4 * Userspace RCU library - example RCU-based lock-free stack
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/rculfstack.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_lfs_stack_rcu s
;
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_lfs_node_rcu
*node
= malloc(sizeof(*node
));
179 cds_lfs_node_init_rcu(node
);
180 /* No rcu read-side is needed for push */
181 cds_lfs_push_rcu(&s
, node
);
182 nr_successful_enqueues
++;
184 if (unlikely(wdelay
))
188 if (unlikely(!test_duration_enqueue()))
192 rcu_unregister_thread();
194 count
[0] = nr_enqueues
;
195 count
[1] = nr_successful_enqueues
;
196 printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
197 "enqueues %llu successful_enqueues %llu\n",
198 pthread_self(), (unsigned long)gettid(), nr_enqueues
,
199 nr_successful_enqueues
);
204 void *thr_dequeuer(void *_count
)
206 unsigned long long *count
= _count
;
209 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
210 "dequeuer", pthread_self(), (unsigned long)gettid());
214 ret
= rcu_defer_register_thread();
216 printf("Error in rcu_defer_register_thread\n");
219 rcu_register_thread();
227 struct cds_lfs_node_rcu
*node
;
230 node
= cds_lfs_pop_rcu(&s
);
233 defer_rcu(free
, node
);
234 nr_successful_dequeues
++;
237 if (unlikely(!test_duration_dequeue()))
239 if (unlikely(rduration
))
240 loop_sleep(rduration
);
243 rcu_unregister_thread();
244 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_lfs_stack_rcu
*s
, unsigned long long *nr_dequeues
)
257 struct cds_lfs_node_rcu
*node
;
260 node
= cds_lfs_pop_rcu(s
);
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_lfs_init_rcu(&s
);
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(&s
, &end_dequeues
);
405 printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
406 tot_enqueues
, tot_dequeues
);
407 printf_verbose("total number of successful enqueues : %llu, "
408 "successful dequeues %llu\n",
409 tot_successful_enqueues
, tot_successful_dequeues
);
410 printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
412 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
413 "successful enqueues %12llu successful dequeues %12llu "
414 "end_dequeues %llu nr_ops %12llu\n",
415 argv
[0], duration
, nr_enqueuers
, wdelay
,
416 nr_dequeuers
, rduration
, tot_enqueues
, tot_dequeues
,
417 tot_successful_enqueues
,
418 tot_successful_dequeues
, end_dequeues
,
419 tot_enqueues
+ tot_dequeues
);
420 if (tot_successful_enqueues
!= tot_successful_dequeues
+ end_dequeues
)
421 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
422 "succ. dequeues + end dequeues %llu.\n",
423 tot_successful_enqueues
,
424 tot_successful_dequeues
+ end_dequeues
);
426 free(count_enqueuer
);
427 free(count_dequeuer
);