tests/test_rwlock_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 #define _GNU_SOURCE
  24 #include <stdio.h>
  25 #include <pthread.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/types.h>
  29 #include <sys/wait.h>
  30 #include <unistd.h>
  31 #include <stdio.h>
  32 #include <assert.h>
  33 #include <pthread.h>
  34 #include <errno.h>
  35
  36 #include <urcu/arch.h>
  37
  38 #include "thread-id.h"
  39
  40 #include <urcu.h>
  41
  42 struct test_array {
  43         int a;
  44 };
  45
  46 pthread_rwlock_t lock = PTHREAD_RWLOCK_INITIALIZER;
  47
  48 static struct test_array test_array = { 8 };
  49
  50 #define OUTER_READ_LOOP 200U
  51 #define INNER_READ_LOOP 100000U
  52 #define READ_LOOP ((unsigned long long)OUTER_READ_LOOP * INNER_READ_LOOP)
  53
  54 #define OUTER_WRITE_LOOP 10U
  55 #define INNER_WRITE_LOOP 200U
  56 #define WRITE_LOOP ((unsigned long long)OUTER_WRITE_LOOP * INNER_WRITE_LOOP)
  57
  58 static int num_read;
  59 static int num_write;
  60
  61 #define NR_READ num_read
  62 #define NR_WRITE num_write
  63
  64 static cycles_t __attribute__((aligned(CAA_CACHE_LINE_SIZE))) *reader_time;
  65 static cycles_t __attribute__((aligned(CAA_CACHE_LINE_SIZE))) *writer_time;
  66
  67 void *thr_reader(void *arg)
  68 {
  69         int i, j;
  70         cycles_t time1, time2;
  71
  72         printf("thread_begin %s, tid %lu\n",
  73                 "reader", urcu_get_thread_id());
  74         sleep(2);
  75
  76         time1 = caa_get_cycles();
  77         for (i = 0; i < OUTER_READ_LOOP; i++) {
  78                 for (j = 0; j < INNER_READ_LOOP; j++) {
  79                         pthread_rwlock_rdlock(&lock);
  80                         assert(test_array.a == 8);
  81                         pthread_rwlock_unlock(&lock);
  82                 }
  83         }
  84         time2 = caa_get_cycles();
  85
  86         reader_time[(unsigned long)arg] = time2 - time1;
  87
  88         sleep(2);
  89         printf("thread_end %s, tid %lu\n",
  90                 "reader", urcu_get_thread_id());
  91         return ((void*)1);
  92
  93 }
  94
  95 void *thr_writer(void *arg)
  96 {
  97         int i, j;
  98         cycles_t time1, time2;
  99
 100         printf("thread_begin %s, tid %lu\n",
 101                 "writer", urcu_get_thread_id());
 102         sleep(2);
 103
 104         for (i = 0; i < OUTER_WRITE_LOOP; i++) {
 105                 for (j = 0; j < INNER_WRITE_LOOP; j++) {
 106                         time1 = caa_get_cycles();
 107                         pthread_rwlock_wrlock(&lock);
 108                         test_array.a = 8;
 109                         pthread_rwlock_unlock(&lock);
 110                         time2 = caa_get_cycles();
 111                         writer_time[(unsigned long)arg] += time2 - time1;
 112                         usleep(1);
 113                 }
 114         }
 115
 116         printf("thread_end %s, tid %lu\n",
 117                 "writer", urcu_get_thread_id());
 118         return ((void*)2);
 119 }
 120
 121 int main(int argc, char **argv)
 122 {
 123         int err;
 124         pthread_t *tid_reader, *tid_writer;
 125         void *tret;
 126         int i;
 127         cycles_t tot_rtime = 0;
 128         cycles_t tot_wtime = 0;
 129
 130         if (argc < 2) {
 131                 printf("Usage : %s nr_readers nr_writers\n", argv[0]);
 132                 exit(-1);
 133         }
 134         num_read = atoi(argv[1]);
 135         num_write = atoi(argv[2]);
 136
 137         reader_time = malloc(sizeof(*reader_time) * num_read);
 138         writer_time = malloc(sizeof(*writer_time) * num_write);
 139         tid_reader = malloc(sizeof(*tid_reader) * num_read);
 140         tid_writer = malloc(sizeof(*tid_writer) * num_write);
 141
 142         printf("thread %-6s, tid %lu\n",
 143                 "main", urcu_get_thread_id());
 144
 145         for (i = 0; i < NR_READ; i++) {
 146                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 147                                      (void *)(long)i);
 148                 if (err != 0)
 149                         exit(1);
 150         }
 151         for (i = 0; i < NR_WRITE; i++) {
 152                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 153                                      (void *)(long)i);
 154                 if (err != 0)
 155                         exit(1);
 156         }
 157
 158         sleep(10);
 159
 160         for (i = 0; i < NR_READ; i++) {
 161                 err = pthread_join(tid_reader[i], &tret);
 162                 if (err != 0)
 163                         exit(1);
 164                 tot_rtime += reader_time[i];
 165         }
 166         for (i = 0; i < NR_WRITE; i++) {
 167                 err = pthread_join(tid_writer[i], &tret);
 168                 if (err != 0)
 169                         exit(1);
 170                 tot_wtime += writer_time[i];
 171         }
 172         printf("Time per read : %g cycles\n",
 173                (double)tot_rtime / ((double)NR_READ * (double)READ_LOOP));
 174         printf("Time per write : %g cycles\n",
 175                (double)tot_wtime / ((double)NR_WRITE * (double)WRITE_LOOP));
 176
 177         free(reader_time);
 178         free(writer_time);
 179         free(tid_reader);
 180         free(tid_writer);
 181
 182         return 0;
 183 }