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 static int num_read;
  70 static int num_write;
  71
  72 #define NR_READ num_read
  73 #define NR_WRITE num_write
  74
  75 static cycles_t __attribute__((aligned(128))) *reader_time;
  76 static cycles_t __attribute__((aligned(128))) *writer_time;
  77
  78 void *thr_reader(void *arg)
  79 {
  80         int i, j;
  81         cycles_t time1, time2;
  82
  83         printf("thread_begin %s, thread id : %lx, tid %lu\n",
  84                         "reader", pthread_self(), (unsigned long)gettid());
  85         sleep(2);
  86
  87         time1 = get_cycles();
  88         for (i = 0; i < OUTER_READ_LOOP; i++) {
  89                 for (j = 0; j < INNER_READ_LOOP; j++) {
  90                         pthread_rwlock_rdlock(&lock);
  91                         assert(test_array.a == 8);
  92                         pthread_rwlock_unlock(&lock);
  93                 }
  94         }
  95         time2 = get_cycles();
  96
  97         reader_time[(unsigned long)arg] = time2 - time1;
  98
  99         sleep(2);
 100         printf("thread_end %s, thread id : %lx, tid %lu\n",
 101                         "reader", pthread_self(), (unsigned long)gettid());
 102         return ((void*)1);
 103
 104 }
 105
 106 void *thr_writer(void *arg)
 107 {
 108         int i, j;
 109         cycles_t time1, time2;
 110
 111         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 112                         "writer", pthread_self(), (unsigned long)gettid());
 113         sleep(2);
 114
 115         for (i = 0; i < OUTER_WRITE_LOOP; i++) {
 116                 for (j = 0; j < INNER_WRITE_LOOP; j++) {
 117                         time1 = get_cycles();
 118                         pthread_rwlock_wrlock(&lock);
 119                         test_array.a = 8;
 120                         pthread_rwlock_unlock(&lock);
 121                         time2 = get_cycles();
 122                         writer_time[(unsigned long)arg] += time2 - time1;
 123                         usleep(1);
 124                 }
 125         }
 126
 127         printf("thread_end %s, thread id : %lx, tid %lu\n",
 128                         "writer", pthread_self(), (unsigned long)gettid());
 129         return ((void*)2);
 130 }
 131
 132 int main(int argc, char **argv)
 133 {
 134         int err;
 135         pthread_t *tid_reader, *tid_writer;
 136         void *tret;
 137         int i;
 138         cycles_t tot_rtime = 0;
 139         cycles_t tot_wtime = 0;
 140
 141         if (argc < 2) {
 142                 printf("Usage : %s nr_readers nr_writers\n", argv[0]);
 143                 exit(-1);
 144         }
 145         num_read = atoi(argv[1]);
 146         num_write = atoi(argv[2]);
 147
 148         reader_time = malloc(sizeof(*reader_time) * num_read);
 149         writer_time = malloc(sizeof(*writer_time) * num_write);
 150         tid_reader = malloc(sizeof(*tid_reader) * num_read);
 151         tid_writer = malloc(sizeof(*tid_writer) * num_write);
 152
 153         printf("thread %-6s, thread id : %lx, tid %lu\n",
 154                         "main", pthread_self(), (unsigned long)gettid());
 155
 156         for (i = 0; i < NR_READ; i++) {
 157                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 158                                      (void *)(long)i);
 159                 if (err != 0)
 160                         exit(1);
 161         }
 162         for (i = 0; i < NR_WRITE; i++) {
 163                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 164                                      (void *)(long)i);
 165                 if (err != 0)
 166                         exit(1);
 167         }
 168
 169         sleep(10);
 170
 171         for (i = 0; i < NR_READ; i++) {
 172                 err = pthread_join(tid_reader[i], &tret);
 173                 if (err != 0)
 174                         exit(1);
 175                 tot_rtime += reader_time[i];
 176         }
 177         for (i = 0; i < NR_WRITE; i++) {
 178                 err = pthread_join(tid_writer[i], &tret);
 179                 if (err != 0)
 180                         exit(1);
 181                 tot_wtime += writer_time[i];
 182         }
 183         printf("Time per read : %g cycles\n",
 184                (double)tot_rtime / ((double)NR_READ * (double)READ_LOOP));
 185         printf("Time per write : %g cycles\n",
 186                (double)tot_wtime / ((double)NR_WRITE * (double)WRITE_LOOP));
 187
 188         free(reader_time);
 189         free(writer_time);
 190         free(tid_reader);
 191         free(tid_writer);
 192
 193         return 0;
 194 }