The
timer_settime() sets the next expiration time of the timer with ID
timerid to the
it_value (see
itimerspec(3)) specified in the
tim argument. If the value is 0, the timer is disarmed. If the argument
otim is not
NULL the old timer settingas are returned.
If the
flags argument is set to
TIMER_RELTIME then the expiration time is set to the value in nanoseconds specified in the
tim argument from the time the call to
timer_settime() was made. If the
flags argument is set to
TIMER_ABSTIME then the expiration time is set to be equal to the difference between the clock associated with this timer, and the value specified in the
tim argument. If that time has already passed, then the call succeeds, and the expiration notification occurs.
If the
it_interval of the
tim argument is non-zero, then the timer reloads upon expiration.
The
timer_gettime() function returns the current settings of the timer specified by the
timerid argument in the
tim argument.
Only one notification event (signal) can be pending for a given timer and process. If a timer expires while the signal is still queued for delivery, then the overrun counter for that timer is increased. The counter can store values up to
DELAYTIMER_MAX. When the signal is finally delivered to the process, then the
timer_getoverrun() function can be used to retrieve the overrun counter for the timer specified in the
timerid argument.