ualarm(3) - NetBSD Manual Pages

UALARM(3)               NetBSD Library Functions Manual              UALARM(3)


NAME

     ualarm -- schedule signal after specified time


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <unistd.h>

     useconds_t
     ualarm(useconds_t microseconds, useconds_t interval);


DESCRIPTION

     This is a simplified interface to setitimer(2).

     The ualarm() function waits a count of microseconds before asserting the
     terminating signal SIGALRM.  System activity or time used in processing
     the call may cause a slight delay.

     If the interval argument is non-zero, the SIGALRM signal will be sent to
     the process every interval microseconds after the timer expires (e.g.
     after microseconds microseconds have passed).


RETURN VALUES

     When the signal has successfully been caught, ualarm() returns the amount
     of time left on the clock.  The maximum number of microseconds allowed is
     2147483647.  If there is an error setting the timer, ualarm() returns
     ((useconds_t) -1).


SEE ALSO

     getitimer(2), setitimer(2), sigaction(2), sigsuspend(2), alarm(3),
     signal(3), sigvec(3), sleep(3), usleep(3)


STANDARDS

     The ualarm() function conforms to IEEE Std 1003.1-2001 (``POSIX.1'').
     However, the later IEEE Std 1003.1-2008 (``POSIX.1'') revision removed
     the function from the specification.


HISTORY

     The ualarm() function appeared in 4.3BSD.

NetBSD 9.0                        May 2, 2011                       NetBSD 9.0