NAME
reltimer — relatively arm a per-process timer
SYNOPSIS
#include <sys/timers.h>
int reltimer(
timer_t timerid,
struct itimerspec *value,
struct itimerspec *ovalue
);
DESCRIPTION
The
reltimer()
function sets the
it_value
of the specified timer to an offset from the current clock setting.
If
reltimer()
specifies a
value
argument with the
it_value
member equal to zero, the timer is disabled.
reltimer()
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 its resolution;
timer values larger than the maximum value of the specified timer
are rounded down to the maximum value (see
mktimer(3C)).
reltimer()
returns in the
ovalue
parameter 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
ovalue
are subject to the resolution of the timer,
and are the same values that would be returned by a
gettimer()
call.
The behavior of this function is undefined if
value
is NULL.
RETURN VALUE
Upon successful completion,
reltimer()
returns zero; otherwise, it returns -1 and sets
errno
to indicate the error.
ERRORS
reltimer()
fails if any of the following conditions are encountered:
- [EINVAL]
timerid
does not correspond to an ID returned by
mktimer()
or the value structure specified a nanosecond value
less than zero or greater than or equal to 1000 million.
- [EIO]
An error occurred while accessing the clock device.
FILES
/usr/include/sys/timers.h
STANDARDS CONFORMANCE
reltimer(): AES
Printable version
