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 #ifdef __linux__
  39 #include <syscall.h>
  40 #endif
  41
  42 #if defined(_syscall0)
  43 _syscall0(pid_t, gettid)
  44 #elif defined(__NR_gettid)
  45 static inline pid_t gettid(void)
  46 {
  47         return syscall(__NR_gettid);
  48 }
  49 #else
  50 #warning "use pid as tid"
  51 static inline pid_t gettid(void)
  52 {
  53         return getpid();
  54 }
  55 #endif
  56
  57 #include <urcu.h>
  58
  59 struct test_array {
  60         int a;
  61 };
  62
  63 pthread_rwlock_t lock = PTHREAD_RWLOCK_INITIALIZER;
  64
  65 static struct test_array test_array = { 8 };
  66
  67 #define OUTER_READ_LOOP 200U
  68 #define INNER_READ_LOOP 100000U
  69 #define READ_LOOP ((unsigned long long)OUTER_READ_LOOP * INNER_READ_LOOP)
  70
  71 #define OUTER_WRITE_LOOP 10U
  72 #define INNER_WRITE_LOOP 200U
  73 #define WRITE_LOOP ((unsigned long long)OUTER_WRITE_LOOP * INNER_WRITE_LOOP)
  74
  75 static int num_read;
  76 static int num_write;
  77
  78 #define NR_READ num_read
  79 #define NR_WRITE num_write
  80
  81 static cycles_t __attribute__((aligned(CAA_CACHE_LINE_SIZE))) *reader_time;
  82 static cycles_t __attribute__((aligned(CAA_CACHE_LINE_SIZE))) *writer_time;
  83
  84 void *thr_reader(void *arg)
  85 {
  86         int i, j;
  87         cycles_t time1, time2;
  88
  89         printf("thread_begin %s, thread id : %lx, tid %lu\n",
  90                         "reader", (unsigned long) pthread_self(),
  91                         (unsigned long) gettid());
  92         sleep(2);
  93
  94         time1 = caa_get_cycles();
  95         for (i = 0; i < OUTER_READ_LOOP; i++) {
  96                 for (j = 0; j < INNER_READ_LOOP; j++) {
  97                         pthread_rwlock_rdlock(&lock);
  98                         assert(test_array.a == 8);
  99                         pthread_rwlock_unlock(&lock);
 100                 }
 101         }
 102         time2 = caa_get_cycles();
 103
 104         reader_time[(unsigned long)arg] = time2 - time1;
 105
 106         sleep(2);
 107         printf("thread_end %s, thread id : %lx, tid %lu\n",
 108                         "reader", (unsigned long) pthread_self(),
 109                         (unsigned long) gettid());
 110         return ((void*)1);
 111
 112 }
 113
 114 void *thr_writer(void *arg)
 115 {
 116         int i, j;
 117         cycles_t time1, time2;
 118
 119         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 120                         "writer", (unsigned long) pthread_self(),
 121                         (unsigned long) gettid());
 122         sleep(2);
 123
 124         for (i = 0; i < OUTER_WRITE_LOOP; i++) {
 125                 for (j = 0; j < INNER_WRITE_LOOP; j++) {
 126                         time1 = caa_get_cycles();
 127                         pthread_rwlock_wrlock(&lock);
 128                         test_array.a = 8;
 129                         pthread_rwlock_unlock(&lock);
 130                         time2 = caa_get_cycles();
 131                         writer_time[(unsigned long)arg] += time2 - time1;
 132                         usleep(1);
 133                 }
 134         }
 135
 136         printf("thread_end %s, thread id : %lx, tid %lu\n",
 137                         "writer", (unsigned long) pthread_self(),
 138                         (unsigned long) gettid());
 139         return ((void*)2);
 140 }
 141
 142 int main(int argc, char **argv)
 143 {
 144         int err;
 145         pthread_t *tid_reader, *tid_writer;
 146         void *tret;
 147         int i;
 148         cycles_t tot_rtime = 0;
 149         cycles_t tot_wtime = 0;
 150
 151         if (argc < 2) {
 152                 printf("Usage : %s nr_readers nr_writers\n", argv[0]);
 153                 exit(-1);
 154         }
 155         num_read = atoi(argv[1]);
 156         num_write = atoi(argv[2]);
 157
 158         reader_time = calloc(num_read, sizeof(*reader_time));
 159         writer_time = calloc(num_write, sizeof(*writer_time));
 160         tid_reader = calloc(num_read, sizeof(*tid_reader));
 161         tid_writer = calloc(num_write, sizeof(*tid_writer));
 162
 163         printf("thread %-6s, thread id : %lx, tid %lu\n",
 164                         "main", (unsigned long) pthread_self(),
 165                         (unsigned long) gettid());
 166
 167         for (i = 0; i < NR_READ; i++) {
 168                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 169                                      (void *)(long)i);
 170                 if (err != 0)
 171                         exit(1);
 172         }
 173         for (i = 0; i < NR_WRITE; i++) {
 174                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 175                                      (void *)(long)i);
 176                 if (err != 0)
 177                         exit(1);
 178         }
 179
 180         sleep(10);
 181
 182         for (i = 0; i < NR_READ; i++) {
 183                 err = pthread_join(tid_reader[i], &tret);
 184                 if (err != 0)
 185                         exit(1);
 186                 tot_rtime += reader_time[i];
 187         }
 188         for (i = 0; i < NR_WRITE; i++) {
 189                 err = pthread_join(tid_writer[i], &tret);
 190                 if (err != 0)
 191                         exit(1);
 192                 tot_wtime += writer_time[i];
 193         }
 194         printf("Time per read : %g cycles\n",
 195                (double)tot_rtime / ((double)NR_READ * (double)READ_LOOP));
 196         printf("Time per write : %g cycles\n",
 197                (double)tot_wtime / ((double)NR_WRITE * (double)WRITE_LOOP));
 198
 199         free(reader_time);
 200         free(writer_time);
 201         free(tid_reader);
 202         free(tid_writer);
 203
 204         return 0;
 205 }