test_urcu_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 <arch.h>
  34
  35 #if defined(_syscall0)
  36 _syscall0(pid_t, gettid)
  37 #elif defined(__NR_gettid)
  38 static inline pid_t gettid(void)
  39 {
  40         return syscall(__NR_gettid);
  41 }
  42 #else
  43 #warning "use pid as tid"
  44 static inline pid_t gettid(void)
  45 {
  46         return getpid();
  47 }
  48 #endif
  49
  50 #define _LGPL_SOURCE
  51 #include "urcu.h"
  52
  53 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
  54
  55 void rcu_copy_mutex_lock(void)
  56 {
  57         int ret;
  58         ret = pthread_mutex_lock(&rcu_copy_mutex);
  59         if (ret) {
  60                 perror("Error in pthread mutex lock");
  61                 exit(-1);
  62         }
  63 }
  64
  65 void rcu_copy_mutex_unlock(void)
  66 {
  67         int ret;
  68
  69         ret = pthread_mutex_unlock(&rcu_copy_mutex);
  70         if (ret) {
  71                 perror("Error in pthread mutex unlock");
  72                 exit(-1);
  73         }
  74 }
  75
  76 struct test_array {
  77         int a;
  78 };
  79
  80 static struct test_array *test_rcu_pointer;
  81
  82 #define OUTER_READ_LOOP 2000U
  83 #define INNER_READ_LOOP 100000U
  84 #define READ_LOOP ((unsigned long long)OUTER_READ_LOOP * INNER_READ_LOOP)
  85
  86 #define OUTER_WRITE_LOOP 10U
  87 #define INNER_WRITE_LOOP 200U
  88 #define WRITE_LOOP ((unsigned long long)OUTER_WRITE_LOOP * INNER_WRITE_LOOP)
  89
  90 #define NR_READ 10
  91 #define NR_WRITE 9
  92
  93 static cycles_t reader_time[NR_READ] __attribute__((aligned(128)));
  94 static cycles_t writer_time[NR_WRITE] __attribute__((aligned(128)));
  95
  96 void *thr_reader(void *arg)
  97 {
  98         int i, j;
  99         struct test_array *local_ptr;
 100         cycles_t time1, time2;
 101
 102         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 103                         "reader", pthread_self(), (unsigned long)gettid());
 104         sleep(2);
 105
 106         rcu_register_thread();
 107
 108         time1 = get_cycles();
 109         for (i = 0; i < OUTER_READ_LOOP; i++) {
 110                 for (j = 0; j < INNER_READ_LOOP; j++) {
 111                         rcu_read_lock();
 112                         local_ptr = rcu_dereference(test_rcu_pointer);
 113                         if (local_ptr) {
 114                                 assert(local_ptr->a == 8);
 115                         }
 116                         rcu_read_unlock();
 117                 }
 118         }
 119         time2 = get_cycles();
 120
 121         rcu_unregister_thread();
 122
 123         reader_time[(unsigned long)arg] = time2 - time1;
 124
 125         sleep(2);
 126         printf("thread_end %s, thread id : %lx, tid %lu\n",
 127                         "reader", pthread_self(), (unsigned long)gettid());
 128         return ((void*)1);
 129
 130 }
 131
 132 void *thr_writer(void *arg)
 133 {
 134         int i, j;
 135         struct test_array *new, *old;
 136         cycles_t time1, time2;
 137
 138         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 139                         "writer", pthread_self(), (unsigned long)gettid());
 140         sleep(2);
 141
 142         for (i = 0; i < OUTER_WRITE_LOOP; i++) {
 143                 for (j = 0; j < INNER_WRITE_LOOP; j++) {
 144                         time1 = get_cycles();
 145                         new = malloc(sizeof(struct test_array));
 146                         rcu_copy_mutex_lock();
 147                         old = test_rcu_pointer;
 148                         if (old) {
 149                                 assert(old->a == 8);
 150                         }
 151                         new->a = 8;
 152                         old = rcu_publish_content(&test_rcu_pointer, new);
 153                         rcu_copy_mutex_unlock();
 154                         /* can be done after unlock */
 155                         if (old) {
 156                                 old->a = 0;
 157                         }
 158                         free(old);
 159                         time2 = get_cycles();
 160                         writer_time[(unsigned long)arg] += time2 - time1;
 161                         usleep(1);
 162                 }
 163         }
 164
 165         printf("thread_end %s, thread id : %lx, tid %lu\n",
 166                         "writer", pthread_self(), (unsigned long)gettid());
 167         return ((void*)2);
 168 }
 169
 170 int main()
 171 {
 172         int err;
 173         pthread_t tid_reader[NR_READ], tid_writer[NR_WRITE];
 174         void *tret;
 175         int i;
 176         cycles_t tot_rtime = 0;
 177         cycles_t tot_wtime = 0;
 178
 179         printf("thread %-6s, thread id : %lx, tid %lu\n",
 180                         "main", pthread_self(), (unsigned long)gettid());
 181
 182         for (i = 0; i < NR_READ; i++) {
 183                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 184                                      (void *)(long)i);
 185                 if (err != 0)
 186                         exit(1);
 187         }
 188         for (i = 0; i < NR_WRITE; i++) {
 189                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 190                                      (void *)(long)i);
 191                 if (err != 0)
 192                         exit(1);
 193         }
 194
 195         sleep(10);
 196
 197         for (i = 0; i < NR_READ; i++) {
 198                 err = pthread_join(tid_reader[i], &tret);
 199                 if (err != 0)
 200                         exit(1);
 201                 tot_rtime += reader_time[i];
 202         }
 203         for (i = 0; i < NR_WRITE; i++) {
 204                 err = pthread_join(tid_writer[i], &tret);
 205                 if (err != 0)
 206                         exit(1);
 207                 tot_wtime += writer_time[i];
 208         }
 209         free(test_rcu_pointer);
 210         printf("Time per read : %g cycles\n",
 211                (double)tot_rtime / ((double)NR_READ * (double)READ_LOOP));
 212         printf("Time per write : %g cycles\n",
 213                (double)tot_wtime / ((double)NR_WRITE * (double)WRITE_LOOP));
 214
 215         return 0;
 216 }