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 OUTER_WRITE_LOOP 10U
  66 #define INNER_WRITE_LOOP 200U
  67 #define WRITE_LOOP ((unsigned long long)OUTER_WRITE_LOOP * INNER_WRITE_LOOP)
  68
  69 #define NR_READ 10
  70 #define NR_WRITE 9
  71
  72 static cycles_t reader_time[NR_READ] __attribute__((aligned(128)));
  73 static cycles_t writer_time[NR_WRITE] __attribute__((aligned(128)));
  74
  75 void *thr_reader(void *arg)
  76 {
  77         int i, j;
  78         cycles_t time1, time2;
  79
  80         printf("thread_begin %s, thread id : %lx, tid %lu\n",
  81                         "reader", pthread_self(), (unsigned long)gettid());
  82         sleep(2);
  83
  84         time1 = get_cycles();
  85         for (i = 0; i < OUTER_READ_LOOP; i++) {
  86                 for (j = 0; j < INNER_READ_LOOP; j++) {
  87                         pthread_rwlock_rdlock(&lock);
  88                         assert(test_array.a == 8);
  89                         pthread_rwlock_unlock(&lock);
  90                 }
  91         }
  92         time2 = get_cycles();
  93
  94         reader_time[(unsigned long)arg] = time2 - time1;
  95
  96         sleep(2);
  97         printf("thread_end %s, thread id : %lx, tid %lu\n",
  98                         "reader", pthread_self(), (unsigned long)gettid());
  99         return ((void*)1);
 100
 101 }
 102
 103 void *thr_writer(void *arg)
 104 {
 105         int i, j;
 106         cycles_t time1, time2;
 107
 108         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 109                         "writer", pthread_self(), (unsigned long)gettid());
 110         sleep(2);
 111
 112         for (i = 0; i < OUTER_WRITE_LOOP; i++) {
 113                 for (j = 0; j < INNER_WRITE_LOOP; j++) {
 114                         time1 = get_cycles();
 115                         pthread_rwlock_wrlock(&lock);
 116                         test_array.a = 8;
 117                         pthread_rwlock_unlock(&lock);
 118                         time2 = get_cycles();
 119                         writer_time[(unsigned long)arg] += time2 - time1;
 120                         usleep(1);
 121                 }
 122         }
 123
 124         printf("thread_end %s, thread id : %lx, tid %lu\n",
 125                         "writer", pthread_self(), (unsigned long)gettid());
 126         return ((void*)2);
 127 }
 128
 129 int main()
 130 {
 131         int err;
 132         pthread_t tid_reader[NR_READ], tid_writer[NR_WRITE];
 133         void *tret;
 134         int i;
 135         cycles_t tot_rtime = 0;
 136         cycles_t tot_wtime = 0;
 137
 138         printf("thread %-6s, thread id : %lx, tid %lu\n",
 139                         "main", pthread_self(), (unsigned long)gettid());
 140
 141         for (i = 0; i < NR_READ; i++) {
 142                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 143                                      (void *)(long)i);
 144                 if (err != 0)
 145                         exit(1);
 146         }
 147         for (i = 0; i < NR_WRITE; i++) {
 148                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 149                                      (void *)(long)i);
 150                 if (err != 0)
 151                         exit(1);
 152         }
 153
 154         sleep(10);
 155
 156         for (i = 0; i < NR_READ; i++) {
 157                 err = pthread_join(tid_reader[i], &tret);
 158                 if (err != 0)
 159                         exit(1);
 160                 tot_rtime += reader_time[i];
 161         }
 162         for (i = 0; i < NR_WRITE; i++) {
 163                 err = pthread_join(tid_writer[i], &tret);
 164                 if (err != 0)
 165                         exit(1);
 166                 tot_wtime += writer_time[i];
 167         }
 168         printf("Time per read : %g cycles\n",
 169                (double)tot_rtime / ((double)NR_READ * (double)READ_LOOP));
 170         printf("Time per write : %g cycles\n",
 171                (double)tot_wtime / ((double)NR_WRITE * (double)WRITE_LOOP));
 172
 173         return 0;
 174 }