RELTIMER(3)                          SysV                          RELTIMER(3)



NAME
     reltimer - establish timeout intervals of a per-process timer

SYNOPSIS
     #include <sys/timers.h>

     int reltimer (tmrid, val, oval)

     timer_t tmrid;
     struct itimerspec *val;
     struct itimerspec *oval;

DESCRIPTION
     The reltimer function sets the it_value of the specified timer to an
     offset from the current clock setting.

     The tmrid argument specifies the per-process timer to access; the val
     argument points to a type itimerspec structure containing the values of
     the initial and offset timeout intervals. The oval argument points to a
     type itimerspec structure where the current value of the timer is to be
     stored.

     If the reltimer function specifies a val argument with the it_value
     member equal to zero, the timer is disabled. The reltimer function
     updates the it_interval value of the timer to the value specified. Time
     values smaller than the resolution of the specified timer are rounded up
     to the resolution value (4 micorseconds). Time values larger than the
     maximum timeout value of the specified per-process timer are rounded down
     to that maximum value.

     The reltimer function returns in the oval argument a value representing
     the previous amount of time before the timer would have expired or zero
     if the timer was disabled, together with the previous interval timer
     period. The members of oval are subject to the resolution of the timer,
     and are the same values that would be returned by a gettimer(3) call.

     The behavior of this function is undefined if val is NULL.

DIAGNOSTICS
     Upon successful completion, the reltimer function returns 0 (zero).
     Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS
     reltimer fails if:

     [EINVAL]       The timerid argument does not specify an allocated per-
                    process timer, or the val argument points to a nanosecond
                    value less than zero or greater than or equal to 1000
                    million.

     [EIO]          An error occurred while accessing the clock.

SEE ALSO
     alarm(2), getclock(3), gettimer(3), mktimer(3), <sys/timers.h>