RTAPI_PRIO(3)

NAME
rtapi_prio, rtapi_prio_highest, rtapi_prio_lowest, rtapi_prio_next_higher, rtapi_prio_next_lower - thread priority functions

SYNTAX

    int rtapi_prio_highest();
    int rtapi_prio_lowest();
    int rtapi_prio_next_higher(int _prio_);
    int rtapi_prio_next_lower(int _prio_);

ARGUMENTS

prio
    A value returned by a prior rtapi_prio_xxx call

DESCRIPTION

The rtapi_prio_xxxx functions provide a portable way to set task priority. The mapping of actual priority to priority number depends on the RTOS. Priorities range from rtapi_prio_lowest to rtapi_prio_highest, inclusive. To use this API, use one of two methods:

    1. Set your lowest priority task to rtapi_prio_lowest, and for each task of the next lowest priority, set their priorities to rtapi_prio_next_higher(previous).

    2. Set your highest priority task to rtapi_prio_highest, and for each task of the next highest priority, set their priorities to rtapi_prio_next_lower(previous).

N.B.: A high priority task will preempt or interrupt a lower priority task. Linux is always the lowest priority!

REALTIME CONSIDERATIONS

Call these functions only from within init/cleanup code, not from realtime tasks.

RETURN VALUE

Returns an opaque real-time priority number.

SEE ALSO

rtapi_task_new(3)