test/select/speed.c

   1 /*
   2  * Test name: speed.c
   3  *
   4  * Objetive:  Test the time it takes for select to run.
   5  *
   6  * Description: This tests creates a number of udp connections and performs
   7  * a select call waiting on them for reading with timeout of 0.
   8  * This is done 10,000 thousands of times and then the average time it takes
   9  * is computed
  10  *
  11  * Jose M. Gomez
  12  */
  13
  14 #include <sys/types.h>
  15 #include <fcntl.h>
  16 #include <unistd.h>
  17 #include <sys/select.h>
  18 #include <sys/asynchio.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <limits.h>
  22 #include <net/netlib.h>
  23 #include <time.h>
  24
  25 #define NUMBER 12
  26
  27 int main(int argc, char *argv[])
  28 {
  29         char *udp_device;
  30         int fd[NUMBER];
  31         fd_set fds_write;
  32         struct timeval timeout;
  33         time_t start_time, end_time;
  34         int i;
  35
  36         FD_ZERO(&fds_write);
  37         for (i = 0; i < NUMBER; i++) {
  38                 fd[i] = open("/dev/tty", O_RDWR);
  39                 if (fd[i] < 0) {
  40                         fprintf(stderr, "Error opening tty %d\n", i);
  41                         exit(-1);
  42                 }
  43                 FD_SET(fd[i], &fds_write);
  44         }
  45
  46         printf("Select will send 1 msg to terminal and %d to inet: \n", NUMBER);
  47         timeout.tv_sec = 0;
  48         timeout.tv_usec = 0;
  49         /* get initial time */
  50         start_time = time(NULL);
  51         for (i = 0; i < 32000; i++) {
  52                 select(NUMBER + 4, NULL, &fds_write, NULL, &timeout);
  53         }
  54         /* get final time */
  55         end_time = time(NULL);
  56         printf("The select call took on average: %f\n", (float)(end_time - start_time) /  32000.0);
  57         for (i = 0; i < NUMBER; i++) {
  58                 close(fd[i]);
  59         }
  60         return 0;
  61 }