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