4 * Userspace RCU library - test program
6 * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
28 #include <sys/types.h>
33 #include <sys/syscall.h>
38 #if defined(_syscall0)
39 _syscall0(pid_t
, gettid
)
40 #elif defined(__NR_gettid)
41 static inline pid_t
gettid(void)
43 return syscall(__NR_gettid
);
46 #warning "use pid as tid"
47 static inline pid_t
gettid(void)
53 #ifndef DYNAMIC_LINK_TEST
56 #define debug_yield_read()
64 static volatile int test_go
, test_stop
;
68 static struct test_array
*test_rcu_pointer
;
70 static unsigned long duration
;
73 * returns 0 if test should end.
75 static int test_duration_write(void)
80 static int test_duration_read(void)
85 static unsigned long long __thread nr_writes
;
86 static unsigned long long __thread nr_reads
;
88 static unsigned int nr_readers
;
89 static unsigned int nr_writers
;
91 pthread_mutex_t rcu_copy_mutex
= PTHREAD_MUTEX_INITIALIZER
;
93 void rcu_copy_mutex_lock(void)
96 ret
= pthread_mutex_lock(&rcu_copy_mutex
);
98 perror("Error in pthread mutex lock");
103 void rcu_copy_mutex_unlock(void)
107 ret
= pthread_mutex_unlock(&rcu_copy_mutex
);
109 perror("Error in pthread mutex unlock");
115 * malloc/free are reusing memory areas too quickly, which does not let us
116 * test races appropriately. Use a large circular array for allocations.
117 * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
119 #define ARRAY_SIZE (1048576 * nr_writers)
120 #define ARRAY_POISON 0xDEADBEEF
121 static int array_index
;
122 static struct test_array
*test_array
;
124 static struct test_array
*test_array_alloc(void)
126 struct test_array
*ret
;
129 rcu_copy_mutex_lock();
130 index
= array_index
% ARRAY_SIZE
;
131 assert(test_array
[index
].a
== ARRAY_POISON
||
132 test_array
[index
].a
== 0);
133 ret
= &test_array
[index
];
135 if (array_index
== ARRAY_SIZE
)
137 rcu_copy_mutex_unlock();
141 static void test_array_free(struct test_array
*ptr
)
145 rcu_copy_mutex_lock();
146 ptr
->a
= ARRAY_POISON
;
147 rcu_copy_mutex_unlock();
150 void *thr_reader(void *_count
)
152 unsigned long long *count
= _count
;
153 struct test_array
*local_ptr
;
155 printf("thread_begin %s, thread id : %lx, tid %lu\n",
156 "reader", pthread_self(), (unsigned long)gettid());
158 rcu_register_thread();
167 local_ptr
= rcu_dereference(test_rcu_pointer
);
170 assert(local_ptr
->a
== 8);
173 if (unlikely(!test_duration_read()))
177 rcu_unregister_thread();
180 printf("thread_end %s, thread id : %lx, tid %lu\n",
181 "reader", pthread_self(), (unsigned long)gettid());
186 void *thr_writer(void *_count
)
188 unsigned long long *count
= _count
;
189 struct test_array
*new, *old
;
191 printf("thread_begin %s, thread id : %lx, tid %lu\n",
192 "writer", pthread_self(), (unsigned long)gettid());
200 new = test_array_alloc();
201 rcu_copy_mutex_lock();
202 old
= test_rcu_pointer
;
206 old
= rcu_publish_content(&test_rcu_pointer
, new);
207 rcu_copy_mutex_unlock();
208 /* can be done after unlock */
211 test_array_free(old
);
213 if (unlikely(!test_duration_write()))
215 if (unlikely(wdelay
))
219 printf("thread_end %s, thread id : %lx, tid %lu\n",
220 "writer", pthread_self(), (unsigned long)gettid());
225 void show_usage(int argc
, char **argv
)
227 printf("Usage : %s nr_readers nr_writers duration (s)", argv
[0]);
229 printf(" [-r] [-w] (yield reader and/or writer)");
231 printf(" [-d delay] (writer period (us))");
232 printf(" [-a cpu#] [-a cpu#]... (affinity)");
238 int main(int argc
, char **argv
)
241 pthread_t
*tid_reader
, *tid_writer
;
243 unsigned long long *count_reader
, *count_writer
;
244 unsigned long long tot_reads
= 0, tot_writes
= 0;
246 int use_affinity
= 0;
249 show_usage(argc
, argv
);
253 err
= sscanf(argv
[1], "%u", &nr_readers
);
255 show_usage(argc
, argv
);
259 err
= sscanf(argv
[2], "%u", &nr_writers
);
261 show_usage(argc
, argv
);
265 err
= sscanf(argv
[3], "%lu", &duration
);
267 show_usage(argc
, argv
);
273 for (i
= 4; i
< argc
; i
++) {
274 if (argv
[i
][0] != '-')
276 switch (argv
[i
][1]) {
279 yield_active
|= YIELD_READ
;
282 yield_active
|= YIELD_WRITE
;
287 show_usage(argc
, argv
);
291 CPU_SET(a
, &affinity
);
293 printf("Adding CPU %d affinity\n", a
);
297 show_usage(argc
, argv
);
300 wdelay
= atoi(argv
[++i
]);
305 printf("running test for %lu seconds, %u readers, %u writers.\n",
306 duration
, nr_readers
, nr_writers
);
307 printf("Writer delay : %u us.\n", wdelay
);
308 printf("thread %-6s, thread id : %lx, tid %lu\n",
309 "main", pthread_self(), (unsigned long)gettid());
312 && sched_setaffinity(0, sizeof(affinity
), &affinity
) < 0) {
313 perror("sched_setaffinity");
317 test_array
= malloc(sizeof(*test_array
) * ARRAY_SIZE
);
318 tid_reader
= malloc(sizeof(*tid_reader
) * nr_readers
);
319 tid_writer
= malloc(sizeof(*tid_writer
) * nr_writers
);
320 count_reader
= malloc(sizeof(*count_reader
) * nr_readers
);
321 count_writer
= malloc(sizeof(*count_writer
) * nr_writers
);
323 for (i
= 0; i
< nr_readers
; i
++) {
324 err
= pthread_create(&tid_reader
[i
], NULL
, thr_reader
,
329 for (i
= 0; i
< nr_writers
; i
++) {
330 err
= pthread_create(&tid_writer
[i
], NULL
, thr_writer
,
344 for (i
= 0; i
< nr_readers
; i
++) {
345 err
= pthread_join(tid_reader
[i
], &tret
);
348 tot_reads
+= count_reader
[i
];
350 for (i
= 0; i
< nr_writers
; i
++) {
351 err
= pthread_join(tid_writer
[i
], &tret
);
354 tot_writes
+= count_writer
[i
];
357 printf("total number of reads : %llu, writes %llu\n", tot_reads
,
359 test_array_free(test_rcu_pointer
);