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