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>
41 #include <urcu/list.h>
47 /* hardcoded number of CPUs */
50 #if defined(_syscall0)
51 _syscall0(pid_t
, gettid
)
52 #elif defined(__NR_gettid)
53 static inline pid_t
gettid(void)
55 return syscall(__NR_gettid
);
58 #warning "use pid as tid"
59 static inline pid_t
gettid(void)
65 static volatile int test_go
, test_stop
;
67 static unsigned long rduration
;
69 static unsigned long duration
;
71 /* read-side C.S. duration, in loops */
72 static unsigned long wdelay
;
74 static inline void loop_sleep(unsigned long l
)
80 static int verbose_mode
;
82 #define printf_verbose(fmt, args...) \
88 static unsigned int cpu_affinities
[NR_CPUS
];
89 static unsigned int next_aff
= 0;
90 static int use_affinity
= 0;
92 pthread_mutex_t affinity_mutex
= PTHREAD_MUTEX_INITIALIZER
;
94 #ifndef HAVE_CPU_SET_T
95 typedef unsigned long cpu_set_t
;
96 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
97 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
100 static void set_affinity(void)
109 #if HAVE_SCHED_SETAFFINITY
110 ret
= pthread_mutex_lock(&affinity_mutex
);
112 perror("Error in pthread mutex lock");
115 cpu
= cpu_affinities
[next_aff
++];
116 ret
= pthread_mutex_unlock(&affinity_mutex
);
118 perror("Error in pthread mutex unlock");
124 #if SCHED_SETAFFINITY_ARGS == 2
125 sched_setaffinity(0, &mask
);
127 sched_setaffinity(0, sizeof(mask
), &mask
);
129 #endif /* HAVE_SCHED_SETAFFINITY */
133 * returns 0 if test should end.
135 static int test_duration_dequeue(void)
140 static int test_duration_enqueue(void)
145 static unsigned long long __thread nr_dequeues
;
146 static unsigned long long __thread nr_enqueues
;
148 static unsigned long long __thread nr_successful_dequeues
;
149 static unsigned long long __thread nr_successful_enqueues
;
151 static unsigned int nr_enqueuers
;
152 static unsigned int nr_dequeuers
;
154 pthread_mutex_t test_mutex
= PTHREAD_MUTEX_INITIALIZER
;
157 struct cds_list_head node
;
160 static CDS_LIST_HEAD(q
);
163 void test_mutex_lock(void)
166 ret
= pthread_mutex_lock(&test_mutex
);
168 perror("Error in pthread mutex lock");
174 void test_mutex_unlock(void)
178 ret
= pthread_mutex_unlock(&test_mutex
);
180 perror("Error in pthread mutex unlock");
185 void *thr_enqueuer(void *_count
)
187 unsigned long long *count
= _count
;
189 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
190 "enqueuer", pthread_self(), (unsigned long)gettid());
200 struct test
*node
= malloc(sizeof(*node
));
204 cds_list_add_tail(&node
->node
, &q
);
206 nr_successful_enqueues
++;
208 if (unlikely(wdelay
))
212 if (unlikely(!test_duration_enqueue()))
216 count
[0] = nr_enqueues
;
217 count
[1] = nr_successful_enqueues
;
218 printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
219 "enqueues %llu successful_enqueues %llu\n",
220 pthread_self(), (unsigned long)gettid(), nr_enqueues
,
221 nr_successful_enqueues
);
226 void *thr_dequeuer(void *_count
)
228 unsigned long long *count
= _count
;
231 printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
232 "dequeuer", pthread_self(), (unsigned long)gettid());
245 if (!cds_list_empty(&q
)) {
246 node
= cds_list_first_entry(&q
, struct test
, node
);
247 cds_list_del(&node
->node
);
255 nr_successful_dequeues
++;
259 if (unlikely(!test_duration_dequeue()))
261 if (unlikely(rduration
))
262 loop_sleep(rduration
);
265 printf_verbose("dequeuer thread_end, thread id : %lx, tid %lu, "
266 "dequeues %llu, successful_dequeues %llu\n",
267 pthread_self(), (unsigned long)gettid(), nr_dequeues
,
268 nr_successful_dequeues
);
269 count
[0] = nr_dequeues
;
270 count
[1] = nr_successful_dequeues
;
274 void test_end(unsigned long long *nr_dequeues
)
279 if (!cds_list_empty(&q
)) {
280 node
= cds_list_first_entry(&q
, struct test
, node
);
285 cds_list_del(&node
->node
);
286 free(node
); /* no more concurrent access */
292 void show_usage(int argc
, char **argv
)
294 printf("Usage : %s nr_dequeuers nr_enqueuers duration (s)", argv
[0]);
295 printf(" [-d delay] (enqueuer period (in loops))");
296 printf(" [-c duration] (dequeuer period (in loops))");
297 printf(" [-v] (verbose output)");
298 printf(" [-a cpu#] [-a cpu#]... (affinity)");
302 int main(int argc
, char **argv
)
305 pthread_t
*tid_enqueuer
, *tid_dequeuer
;
307 unsigned long long *count_enqueuer
, *count_dequeuer
;
308 unsigned long long tot_enqueues
= 0, tot_dequeues
= 0;
309 unsigned long long tot_successful_enqueues
= 0,
310 tot_successful_dequeues
= 0;
311 unsigned long long end_dequeues
= 0;
315 show_usage(argc
, argv
);
319 err
= sscanf(argv
[1], "%u", &nr_dequeuers
);
321 show_usage(argc
, argv
);
325 err
= sscanf(argv
[2], "%u", &nr_enqueuers
);
327 show_usage(argc
, argv
);
331 err
= sscanf(argv
[3], "%lu", &duration
);
333 show_usage(argc
, argv
);
337 for (i
= 4; i
< argc
; i
++) {
338 if (argv
[i
][0] != '-')
340 switch (argv
[i
][1]) {
343 show_usage(argc
, argv
);
347 cpu_affinities
[next_aff
++] = a
;
349 printf_verbose("Adding CPU %d affinity\n", a
);
353 show_usage(argc
, argv
);
356 rduration
= atol(argv
[++i
]);
360 show_usage(argc
, argv
);
363 wdelay
= atol(argv
[++i
]);
371 printf_verbose("running test for %lu seconds, %u enqueuers, "
373 duration
, nr_enqueuers
, nr_dequeuers
);
374 printf_verbose("Writer delay : %lu loops.\n", rduration
);
375 printf_verbose("Reader duration : %lu loops.\n", wdelay
);
376 printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
377 "main", pthread_self(), (unsigned long)gettid());
379 tid_enqueuer
= malloc(sizeof(*tid_enqueuer
) * nr_enqueuers
);
380 tid_dequeuer
= malloc(sizeof(*tid_dequeuer
) * nr_dequeuers
);
381 count_enqueuer
= malloc(2 * sizeof(*count_enqueuer
) * nr_enqueuers
);
382 count_dequeuer
= malloc(2 * sizeof(*count_dequeuer
) * nr_dequeuers
);
386 for (i
= 0; i
< nr_enqueuers
; i
++) {
387 err
= pthread_create(&tid_enqueuer
[i
], NULL
, thr_enqueuer
,
388 &count_enqueuer
[2 * i
]);
392 for (i
= 0; i
< nr_dequeuers
; i
++) {
393 err
= pthread_create(&tid_dequeuer
[i
], NULL
, thr_dequeuer
,
394 &count_dequeuer
[2 * i
]);
403 for (i
= 0; i
< duration
; i
++) {
411 for (i
= 0; i
< nr_enqueuers
; i
++) {
412 err
= pthread_join(tid_enqueuer
[i
], &tret
);
415 tot_enqueues
+= count_enqueuer
[2 * i
];
416 tot_successful_enqueues
+= count_enqueuer
[2 * i
+ 1];
418 for (i
= 0; i
< nr_dequeuers
; i
++) {
419 err
= pthread_join(tid_dequeuer
[i
], &tret
);
422 tot_dequeues
+= count_dequeuer
[2 * i
];
423 tot_successful_dequeues
+= count_dequeuer
[2 * i
+ 1];
426 test_end(&end_dequeues
);
428 printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
429 tot_enqueues
, tot_dequeues
);
430 printf_verbose("total number of successful enqueues : %llu, "
431 "successful dequeues %llu\n",
432 tot_successful_enqueues
, tot_successful_dequeues
);
433 printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
435 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
436 "successful enqueues %12llu successful dequeues %12llu "
437 "end_dequeues %llu nr_ops %12llu\n",
438 argv
[0], duration
, nr_enqueuers
, wdelay
,
439 nr_dequeuers
, rduration
, tot_enqueues
, tot_dequeues
,
440 tot_successful_enqueues
,
441 tot_successful_dequeues
, end_dequeues
,
442 tot_enqueues
+ tot_dequeues
);
443 if (tot_successful_enqueues
!= tot_successful_dequeues
+ end_dequeues
)
444 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
445 "succ. dequeues + end dequeues %llu.\n",
446 tot_successful_enqueues
,
447 tot_successful_dequeues
+ end_dequeues
);
449 free(count_enqueuer
);
450 free(count_dequeuer
);