test_qsbr_timing.c

   1 /*
   2  * test_qsbr_timing.c
   3  *
   4  * Userspace QSBR - 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-qsbr.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                 _rcu_quiescent_state();
 119         }
 120         time2 = get_cycles();
 121
 122         rcu_unregister_thread();
 123
 124         reader_time[(unsigned long)arg] = time2 - time1;
 125
 126         sleep(2);
 127         printf("thread_end %s, thread id : %lx, tid %lu\n",
 128                         "reader", pthread_self(), (unsigned long)gettid());
 129         return ((void*)1);
 130
 131 }
 132
 133 void *thr_writer(void *arg)
 134 {
 135         int i, j;
 136         struct test_array *new, *old;
 137         cycles_t time1, time2;
 138
 139         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 140                         "writer", pthread_self(), (unsigned long)gettid());
 141         sleep(2);
 142
 143         for (i = 0; i < OUTER_WRITE_LOOP; i++) {
 144                 for (j = 0; j < INNER_WRITE_LOOP; j++) {
 145                         time1 = get_cycles();
 146                         new = malloc(sizeof(struct test_array));
 147                         rcu_copy_mutex_lock();
 148                         old = test_rcu_pointer;
 149                         if (old) {
 150                                 assert(old->a == 8);
 151                         }
 152                         new->a = 8;
 153                         old = _rcu_publish_content(&test_rcu_pointer, new);
 154                         rcu_copy_mutex_unlock();
 155                         /* can be done after unlock */
 156                         if (old) {
 157                                 old->a = 0;
 158                         }
 159                         free(old);
 160                         time2 = get_cycles();
 161                         writer_time[(unsigned long)arg] += time2 - time1;
 162                         usleep(1);
 163                 }
 164         }
 165
 166         printf("thread_end %s, thread id : %lx, tid %lu\n",
 167                         "writer", pthread_self(), (unsigned long)gettid());
 168         return ((void*)2);
 169 }
 170
 171 int main()
 172 {
 173         int err;
 174         pthread_t tid_reader[NR_READ], tid_writer[NR_WRITE];
 175         void *tret;
 176         int i;
 177         cycles_t tot_rtime = 0;
 178         cycles_t tot_wtime = 0;
 179
 180         printf("thread %-6s, thread id : %lx, tid %lu\n",
 181                         "main", pthread_self(), (unsigned long)gettid());
 182
 183         for (i = 0; i < NR_READ; i++) {
 184                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 185                                      (void *)(long)i);
 186                 if (err != 0)
 187                         exit(1);
 188         }
 189         for (i = 0; i < NR_WRITE; i++) {
 190                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 191                                      (void *)(long)i);
 192                 if (err != 0)
 193                         exit(1);
 194         }
 195
 196         sleep(10);
 197
 198         for (i = 0; i < NR_READ; i++) {
 199                 err = pthread_join(tid_reader[i], &tret);
 200                 if (err != 0)
 201                         exit(1);
 202                 tot_rtime += reader_time[i];
 203         }
 204         for (i = 0; i < NR_WRITE; i++) {
 205                 err = pthread_join(tid_writer[i], &tret);
 206                 if (err != 0)
 207                         exit(1);
 208                 tot_wtime += writer_time[i];
 209         }
 210         free(test_rcu_pointer);
 211         printf("Time per read : %g cycles\n",
 212                (double)tot_rtime / ((double)NR_READ * (double)READ_LOOP));
 213         printf("Time per write : %g cycles\n",
 214                (double)tot_wtime / ((double)NR_WRITE * (double)WRITE_LOOP));
 215
 216         return 0;
 217 }