external/ibm-public/postfix/dist/src/util/doze.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      doze 3
   6 /* SUMMARY
   7 /*      take a nap
   8 /* SYNOPSIS
   9 /*      #include <iostuff.h>
  10 /*
  11 /*      void    doze(microseconds)
  12 /*      unsigned microseconds;
  13 /* DESCRIPTION
  14 /*      doze() sleeps for the specified number of microseconds. It is
  15 /*      a simple alternative for systems that lack usleep().
  16 /* DIAGNOSTICS
  17 /*      All errors are fatal.
  18 /* LICENSE
  19 /* .ad
  20 /* .fi
  21 /*      The Secure Mailer license must be distributed with this software.
  22 /* AUTHOR(S)
  23 /*      Wietse Venema
  24 /*      IBM T.J. Watson Research
  25 /*      P.O. Box 704
  26 /*      Yorktown Heights, NY 10598, USA
  27 /*--*/
  28
  29 /* System library. */
  30
  31 #include "sys_defs.h"
  32 #include <sys/time.h>
  33 #include <unistd.h>
  34 #include <errno.h>
  35 #ifdef USE_SYS_SELECT_H
  36 #include <sys/select.h>
  37 #endif
  38
  39 /* Utility library. */
  40
  41 #include <msg.h>
  42 #include <iostuff.h>
  43
  44 /* doze - sleep a while */
  45
  46 void    doze(unsigned delay)
  47 {
  48     struct timeval tv;
  49
  50 #define MILLION 1000000
  51
  52     tv.tv_sec = delay / MILLION;
  53     tv.tv_usec = delay % MILLION;
  54     while (select(0, (fd_set *) 0, (fd_set *) 0, (fd_set *) 0, &tv) < 0)
  55         if (errno != EINTR)
  56             msg_fatal("doze: select: %m");
  57 }
  58
  59 #ifdef TEST
  60
  61 #include <stdlib.h>
  62
  63 int     main(int argc, char **argv)
  64 {
  65     unsigned delay;
  66
  67     if (argc != 2 || (delay = atol(argv[1])) == 0)
  68         msg_fatal("usage: %s microseconds", argv[0]);
  69     doze(delay);
  70     exit(0);
  71 }
  72
  73 #endif