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@polymtl.ca>
   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 <sys/syscall.h>
  33 #include <pthread.h>
  34 #include <arch.h>
  35
  36 #if defined(_syscall0)
  37 _syscall0(pid_t, gettid)
  38 #elif defined(__NR_gettid)
  39 static inline pid_t gettid(void)
  40 {
  41         return syscall(__NR_gettid);
  42 }
  43 #else
  44 #warning "use pid as tid"
  45 static inline pid_t gettid(void)
  46 {
  47         return getpid();
  48 }
  49 #endif
  50
  51 #include "urcu.h"
  52
  53 struct test_array {
  54         int a;
  55 };
  56
  57 pthread_rwlock_t lock = PTHREAD_RWLOCK_INITIALIZER;
  58
  59 static struct test_array test_array = { 8 };
  60
  61 #define OUTER_READ_LOOP 200U
  62 #define INNER_READ_LOOP 100000U
  63 #define READ_LOOP ((unsigned long long)OUTER_READ_LOOP * INNER_READ_LOOP)
  64
  65 #define WRITE_LOOP 2000U
  66
  67 #define NR_READ 10
  68 #define NR_WRITE 9
  69
  70 static cycles_t reader_time[NR_READ] __attribute__((aligned(128)));
  71
  72 void *thr_reader(void *arg)
  73 {
  74         int i, j;
  75         cycles_t time1, time2;
  76
  77         printf("thread_begin %s, thread id : %lx, tid %lu\n",
  78                         "reader", pthread_self(), (unsigned long)gettid());
  79         sleep(2);
  80
  81         time1 = get_cycles();
  82         for (i = 0; i < OUTER_READ_LOOP; i++) {
  83                 for (j = 0; j < INNER_READ_LOOP; j++) {
  84                         pthread_rwlock_rdlock(&lock);
  85                         assert(test_array.a == 8);
  86                         pthread_rwlock_unlock(&lock);
  87                 }
  88         }
  89         time2 = get_cycles();
  90
  91         reader_time[(unsigned long)arg] = time2 - time1;
  92
  93         sleep(2);
  94         printf("thread_end %s, thread id : %lx, tid %lu\n",
  95                         "reader", pthread_self(), (unsigned long)gettid());
  96         return ((void*)1);
  97
  98 }
  99
 100 void *thr_writer(void *arg)
 101 {
 102         int i;
 103
 104         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 105                         "writer", pthread_self(), (unsigned long)gettid());
 106         sleep(2);
 107
 108         for (i = 0; i < WRITE_LOOP; i++) {
 109                 pthread_rwlock_wrlock(&lock);
 110                 test_array.a = 8;
 111                 pthread_rwlock_unlock(&lock);
 112                 usleep(1);
 113         }
 114
 115         printf("thread_end %s, thread id : %lx, tid %lu\n",
 116                         "writer", pthread_self(), (unsigned long)gettid());
 117         return ((void*)2);
 118 }
 119
 120 int main()
 121 {
 122         int err;
 123         pthread_t tid_reader[NR_READ], tid_writer[NR_WRITE];
 124         void *tret;
 125         int i;
 126         cycles_t tot_time = 0;
 127
 128         printf("thread %-6s, thread id : %lx, tid %lu\n",
 129                         "main", pthread_self(), (unsigned long)gettid());
 130
 131         for (i = 0; i < NR_READ; i++) {
 132                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 133                                      (void *)(long)i);
 134                 if (err != 0)
 135                         exit(1);
 136         }
 137         for (i = 0; i < NR_WRITE; i++) {
 138                 err = pthread_create(&tid_writer[i], NULL, thr_writer, NULL);
 139                 if (err != 0)
 140                         exit(1);
 141         }
 142
 143         sleep(10);
 144
 145         for (i = 0; i < NR_READ; i++) {
 146                 err = pthread_join(tid_reader[i], &tret);
 147                 if (err != 0)
 148                         exit(1);
 149                 tot_time += reader_time[i];
 150         }
 151         for (i = 0; i < NR_WRITE; i++) {
 152                 err = pthread_join(tid_writer[i], &tret);
 153                 if (err != 0)
 154                         exit(1);
 155         }
 156         printf("Time per read : %g cycles\n",
 157                (double)tot_time / ((double)NR_READ * (double)READ_LOOP));
 158
 159         return 0;
 160 }