tests/benchmark/test_urcu_timing.c

   1 /*
   2  * test_urcu.c
   3  *
   4  * Userspace RCU library - 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 #include <urcu/arch.h>
  34
  35 #include "thread-id.h"
  36
  37 #define _LGPL_SOURCE
  38 #include <urcu.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         }
 112         time2 = caa_get_cycles();
 113
 114         rcu_unregister_thread();
 115
 116         reader_time[(unsigned long)arg] = time2 - time1;
 117
 118         sleep(2);
 119         printf("thread_end %s, tid %lu\n",
 120                 "reader", urcu_get_thread_id());
 121         return ((void*)1);
 122
 123 }
 124
 125 static
 126 void *thr_writer(void *arg)
 127 {
 128         unsigned int i, j;
 129         struct test_array *new, *old;
 130         caa_cycles_t time1, time2;
 131
 132         printf("thread_begin %s, tid %lu\n",
 133                 "writer", urcu_get_thread_id());
 134         sleep(2);
 135
 136         for (i = 0; i < OUTER_WRITE_LOOP; i++) {
 137                 for (j = 0; j < INNER_WRITE_LOOP; j++) {
 138                         time1 = caa_get_cycles();
 139                         new = malloc(sizeof(struct test_array));
 140                         rcu_copy_mutex_lock();
 141                         old = test_rcu_pointer;
 142                         if (old) {
 143                                 assert(old->a == 8);
 144                         }
 145                         new->a = 8;
 146                         old = rcu_xchg_pointer(&test_rcu_pointer, new);
 147                         rcu_copy_mutex_unlock();
 148                         synchronize_rcu();
 149                         /* can be done after unlock */
 150                         if (old) {
 151                                 old->a = 0;
 152                         }
 153                         free(old);
 154                         time2 = caa_get_cycles();
 155                         writer_time[(unsigned long)arg] += time2 - time1;
 156                         usleep(1);
 157                 }
 158         }
 159
 160         printf("thread_end %s, tid %lu\n",
 161                 "writer", urcu_get_thread_id());
 162         return ((void*)2);
 163 }
 164
 165 int main(int argc, char **argv)
 166 {
 167         int err;
 168         pthread_t *tid_reader, *tid_writer;
 169         void *tret;
 170         int i;
 171         caa_cycles_t tot_rtime = 0;
 172         caa_cycles_t tot_wtime = 0;
 173
 174         if (argc < 2) {
 175                 printf("Usage : %s nr_readers nr_writers\n", argv[0]);
 176                 exit(-1);
 177         }
 178         num_read = atoi(argv[1]);
 179         num_write = atoi(argv[2]);
 180
 181         reader_time = calloc(num_read, sizeof(*reader_time));
 182         writer_time = calloc(num_write, sizeof(*writer_time));
 183         tid_reader = calloc(num_read, sizeof(*tid_reader));
 184         tid_writer = calloc(num_write, sizeof(*tid_writer));
 185
 186         printf("thread %-6s, tid %lu\n",
 187                 "main", urcu_get_thread_id());
 188
 189         for (i = 0; i < NR_READ; i++) {
 190                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 191                                      (void *)(long)i);
 192                 if (err != 0)
 193                         exit(1);
 194         }
 195         for (i = 0; i < NR_WRITE; i++) {
 196                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 197                                      (void *)(long)i);
 198                 if (err != 0)
 199                         exit(1);
 200         }
 201
 202         sleep(10);
 203
 204         for (i = 0; i < NR_READ; i++) {
 205                 err = pthread_join(tid_reader[i], &tret);
 206                 if (err != 0)
 207                         exit(1);
 208                 tot_rtime += reader_time[i];
 209         }
 210         for (i = 0; i < NR_WRITE; i++) {
 211                 err = pthread_join(tid_writer[i], &tret);
 212                 if (err != 0)
 213                         exit(1);
 214                 tot_wtime += writer_time[i];
 215         }
 216         free(test_rcu_pointer);
 217         printf("Time per read : %g cycles\n",
 218                (double)tot_rtime / ((double)NR_READ * (double)READ_LOOP));
 219         printf("Time per write : %g cycles\n",
 220                (double)tot_wtime / ((double)NR_WRITE * (double)WRITE_LOOP));
 221
 222         free(reader_time);
 223         free(writer_time);
 224         free(tid_reader);
 225         free(tid_writer);
 226
 227         return 0;
 228 }