ualarm - set the interval timer
useconds_t ualarm(useconds_t useconds, useconds_t interval);
The ualarm() function causes the SIGALRM signal to be generated for
the calling process after the number of real-time microseconds
specified by the useconds argument has elapsed. When the interval
argument is non-zero, repeated timeout notification occurs with a
period in microseconds specified by the interval argument. If the
notification signal, SIGALRM, is not caught or ignored, the calling
process is terminated.
Implementations may place limitations on the granularity of timer
values. For each interval timer, if the requested timer value requires
a finer granularity than the implementation supports, the actual timer
value will be rounded up to the next supported value.
Interactions between ualarm() and either alarm() or sleep() are
The ualarm() function returns the number of microseconds remaining
from the previous ualarm() call. If no timeouts are pending or if
ualarm() has not previously been called, ualarm() returns 0.
No errors are defined.
The ualarm() function is a simplified interface to setitimer(), and
uses the ITIMER_REAL interval timer.
alarm(2), getitimer(2), sleep(3C), <unistd.h>.
First released in Issue 4, Version 2.
Hewlett-Packard Company - 1 - HP-UX Release 11i: November 2000