date and time created 85/03/14 17:52:57 by serge

[unix-history] / usr / src / lib / libc / gen / ualarm.c

/* @(#)ualarm.c 1.1     (Berkeley)      %G% */

#include <sys/time.h>

#define USPS    1000000         /* # of microseconds in a second */

/*
* Generate a SIGALRM signal in ``usecs'' microseconds.
* If ``reload'' is non-zero, keep generating SIGALRM
* every ``reload'' microseconds after the first signal.
*/
unsigned
ualarm(usecs, reload)
       register unsigned usecs;
       register unsigned reload;
{
       struct itimerval new, old;

       new.it_interval.tv_usec = reload % USPS;
       new.it_interval.tv_sec = reload / USPS;
       
       new.it_value.tv_usec = usecs % USPS;
       new.it_value.tv_sec = usecs / USPS;

       if (setitimer(ITIMER_REAL, &new, &old) == 0)
               return (old.it_value.tv_sec * USPS + old.it_value.tv_usec);
       /* else */
               return (-1);
}