test/sysperf/pipe1.c

   1 /*
   2  * pipe1.c
   3  *
   4  * $DragonFly: src/test/sysperf/pipe1.c,v 1.1 2003/08/12 02:29:44 dillon Exp $
   5  */
   6
   7 #include <sys/types.h>
   8 #include <sys/wait.h>
   9 #include "blib.h"
  10
  11 int
  12 main(int ac, char **av)
  13 {
  14     long long count = 0;
  15     long long max;
  16     char c[1];
  17     int j;
  18     int loops;
  19     int fds[2];
  20
  21     printf("tests full duplex pipe 1write,2read,2write,1read loop\n");
  22     if (pipe(fds)) {
  23         perror("pipe");
  24         exit(1);
  25     }
  26     if (fork() == 0) {
  27         /*
  28          * child process
  29          */
  30         close(fds[0]);
  31         while (read(fds[1], c, sizeof(c)) == sizeof(c)) {
  32             write(fds[1], c, sizeof(c));
  33         }
  34         _exit(0);
  35     } else {
  36         /*
  37          * parent process.
  38          */
  39         close(fds[1]);
  40         write(fds[0], c, sizeof(c));    /* prime the caches */
  41         read(fds[0], c, sizeof(c));
  42
  43         start_timing();
  44         for (j = 0; ; ++j) {
  45             write(fds[0], c, sizeof(c));
  46             if (read(fds[0], c, sizeof(c)) != sizeof(c)) {
  47                 fprintf(stderr, "broken pipe during test\n");
  48                 exit(1);
  49             }
  50            if ((j & 31) == 0 && stop_timing(0, NULL))
  51                 break;
  52         }
  53         loops = j;
  54
  55         start_timing();
  56         for (j = 0; j < loops; ++j) {
  57             write(fds[0], c, sizeof(c));
  58             if (read(fds[0], c, sizeof(c)) != sizeof(c)) {
  59                 fprintf(stderr, "broken pipe during test\n");
  60                 exit(1);
  61             }
  62         }
  63         stop_timing(j, "full duplex pipe / 1char:");
  64         close(fds[0]);
  65         while(wait(NULL) >= 0);
  66     }
  67     return(0);
  68 }
  69