tests/benchmark/test_urcu_qsbr_timing.c

   1 /*
   2  * test_qsbr_timing.c
   3  *
   4  * Userspace QSBR - test program
   5  *
   6  * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   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.
  12  *
  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.
  17  *
  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.
  21  */
  22
  23 #include <stdio.h>
  24 #include <pthread.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <sys/types.h>
  28 #include <sys/wait.h>
  29 #include <unistd.h>
  30 #include <stdio.h>
  31 #include <assert.h>
  32 #include <errno.h>
  33
  34 #include <urcu/arch.h>
  35 #include "thread-id.h"
  36
  37 #define _LGPL_SOURCE
  38 #include <urcu-qsbr.h>
  39
  40 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
  41
  42 static
  43 void rcu_copy_mutex_lock(void)
  44 {
  45         int ret;
  46         ret = pthread_mutex_lock(&rcu_copy_mutex);
  47         if (ret) {
  48                 perror("Error in pthread mutex lock");
  49                 exit(-1);
  50         }
  51 }
  52
  53 static
  54 void rcu_copy_mutex_unlock(void)
  55 {
  56         int ret;
  57
  58         ret = pthread_mutex_unlock(&rcu_copy_mutex);
  59         if (ret) {
  60                 perror("Error in pthread mutex unlock");
  61                 exit(-1);
  62         }
  63 }
  64
  65 struct test_array {
  66         int a;
  67 };
  68
  69 static struct test_array *test_rcu_pointer;
  70
  71 #define OUTER_READ_LOOP 2000U
  72 #define INNER_READ_LOOP 100000U
  73 #define READ_LOOP ((unsigned long long)OUTER_READ_LOOP * INNER_READ_LOOP)
  74
  75 #define OUTER_WRITE_LOOP 10U
  76 #define INNER_WRITE_LOOP 200U
  77 #define WRITE_LOOP ((unsigned long long)OUTER_WRITE_LOOP * INNER_WRITE_LOOP)
  78
  79 static int num_read;
  80 static int num_write;
  81
  82 #define NR_READ num_read
  83 #define NR_WRITE num_write
  84
  85 static caa_cycles_t __attribute__((aligned(CAA_CACHE_LINE_SIZE))) *reader_time;
  86 static caa_cycles_t __attribute__((aligned(CAA_CACHE_LINE_SIZE))) *writer_time;
  87
  88 static
  89 void *thr_reader(void *arg)
  90 {
  91         unsigned int i, j;
  92         struct test_array *local_ptr;
  93         caa_cycles_t time1, time2;
  94
  95         printf("thread_begin %s, tid %lu\n",
  96                 "reader", urcu_get_thread_id());
  97         sleep(2);
  98
  99         rcu_register_thread();
 100
 101         time1 = caa_get_cycles();
 102         for (i = 0; i < OUTER_READ_LOOP; i++) {
 103                 for (j = 0; j < INNER_READ_LOOP; j++) {
 104                         _rcu_read_lock();
 105                         local_ptr = _rcu_dereference(test_rcu_pointer);
 106                         if (local_ptr) {
 107                                 assert(local_ptr->a == 8);
 108                         }
 109                         _rcu_read_unlock();
 110                 }
 111                 _rcu_quiescent_state();
 112         }
 113         time2 = caa_get_cycles();
 114
 115         rcu_unregister_thread();
 116
 117         reader_time[(unsigned long)arg] = time2 - time1;
 118
 119         sleep(2);
 120         printf("thread_end %s, tid %lu\n",
 121                 "reader", urcu_get_thread_id());
 122         return ((void*)1);
 123
 124 }
 125
 126 static
 127 void *thr_writer(void *arg)
 128 {
 129         unsigned int i, j;
 130         struct test_array *new, *old;
 131         caa_cycles_t time1, time2;
 132
 133         printf("thread_begin %s, tid %lu\n",
 134                 "writer", urcu_get_thread_id());
 135         sleep(2);
 136
 137         for (i = 0; i < OUTER_WRITE_LOOP; i++) {
 138                 for (j = 0; j < INNER_WRITE_LOOP; j++) {
 139                         time1 = caa_get_cycles();
 140                         new = malloc(sizeof(struct test_array));
 141                         rcu_copy_mutex_lock();
 142                         old = test_rcu_pointer;
 143                         if (old) {
 144                                 assert(old->a == 8);
 145                         }
 146                         new->a = 8;
 147                         old = rcu_xchg_pointer(&test_rcu_pointer, new);
 148                         rcu_copy_mutex_unlock();
 149                         synchronize_rcu();
 150                         /* can be done after unlock */
 151                         if (old) {
 152                                 old->a = 0;
 153                         }
 154                         free(old);
 155                         time2 = caa_get_cycles();
 156                         writer_time[(unsigned long)arg] += time2 - time1;
 157                         usleep(1);
 158                 }
 159         }
 160
 161         printf("thread_end %s, tid %lu\n",
 162                 "writer", urcu_get_thread_id());
 163         return ((void*)2);
 164 }
 165
 166 int main(int argc, char **argv)
 167 {
 168         int err;
 169         pthread_t *tid_reader, *tid_writer;
 170         void *tret;
 171         int i;
 172         caa_cycles_t tot_rtime = 0;
 173         caa_cycles_t tot_wtime = 0;
 174
 175         if (argc < 2) {
 176                 printf("Usage : %s nr_readers nr_writers\n", argv[0]);
 177                 exit(-1);
 178         }
 179         num_read = atoi(argv[1]);
 180         num_write = atoi(argv[2]);
 181
 182         reader_time = calloc(num_read, sizeof(*reader_time));
 183         writer_time = calloc(num_write, sizeof(*writer_time));
 184         tid_reader = calloc(num_read, sizeof(*tid_reader));
 185         tid_writer = calloc(num_write, sizeof(*tid_writer));
 186
 187         printf("thread %-6s, tid %lu\n",
 188                 "main", urcu_get_thread_id());
 189
 190         for (i = 0; i < NR_READ; i++) {
 191                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 192                                      (void *)(long)i);
 193                 if (err != 0)
 194                         exit(1);
 195         }
 196         for (i = 0; i < NR_WRITE; i++) {
 197                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 198                                      (void *)(long)i);
 199                 if (err != 0)
 200                         exit(1);
 201         }
 202
 203         sleep(10);
 204
 205         for (i = 0; i < NR_READ; i++) {
 206                 err = pthread_join(tid_reader[i], &tret);
 207                 if (err != 0)
 208                         exit(1);
 209                 tot_rtime += reader_time[i];
 210         }
 211         for (i = 0; i < NR_WRITE; i++) {
 212                 err = pthread_join(tid_writer[i], &tret);
 213                 if (err != 0)
 214                         exit(1);
 215                 tot_wtime += writer_time[i];
 216         }
 217         free(test_rcu_pointer);
 218         printf("Time per read : %g cycles\n",
 219                (double)tot_rtime / ((double)NR_READ * (double)READ_LOOP));
 220         printf("Time per write : %g cycles\n",
 221                (double)tot_wtime / ((double)NR_WRITE * (double)WRITE_LOOP));
 222
 223         free(reader_time);
 224         free(writer_time);
 225         free(tid_reader);
 226         free(tid_writer);
 227
 228         return 0;
 229 }