usr/src/lib/libbc/libc/gen/common/ualarm.c

   1 #pragma ident   "%Z%%M% %I%     %E% SMI"
   2           /* from UCB 5.1 85/06/05 */
   3
   4 /*
   5  * Copyright (c) 1985 Regents of the University of California.
   6  * All rights reserved.  The Berkeley software License Agreement
   7  * specifies the terms and conditions for redistribution.
   8  */
   9
  10 #include <sys/time.h>
  11
  12 #define USPS    1000000         /* # of microseconds in a second */
  13
  14 /*
  15  * Generate a SIGALRM signal in ``usecs'' microseconds.
  16  * If ``reload'' is non-zero, keep generating SIGALRM
  17  * every ``reload'' microseconds after the first signal.
  18  */
  19 unsigned
  20 ualarm(usecs, reload)
  21         register unsigned usecs;
  22         register unsigned reload;
  23 {
  24         struct itimerval new, old;
  25
  26         new.it_interval.tv_usec = reload % USPS;
  27         new.it_interval.tv_sec = reload / USPS;
  28
  29         new.it_value.tv_usec = usecs % USPS;
  30         new.it_value.tv_sec = usecs / USPS;
  31
  32         if (setitimer(ITIMER_REAL, &new, &old) == 0)
  33                 return (old.it_value.tv_sec * USPS + old.it_value.tv_usec);
  34         /* else */
  35                 return (-1);
  36 }