SCHED.H(3HEAD) Headers SCHED.H(3HEAD)

NAME

sched.h, sched - execution scheduling

SYNOPSIS

#include <sched.h>

DESCRIPTION

The <sched.h> header defines the sched_param structure, which
contains the scheduling parameters required for implementation of
each supported scheduling policy. This structure contains the
following member:

int sched_priority process execution scheduling priority


Each process is controlled by an associated scheduling policy and
priority. Associated with each policy is a priority range. Each
policy definition specifies the minimum priority range for that
policy. The priority ranges for each policy may overlap the priority
ranges of other policies.


The scheduling policies are indicated by the values of the following
symbolic constants:

SCHED_OTHER
Processes are scheduled according to the traditional
Time-Sharing Class (TS) policy as described in
priocntl(2).


SCHED_FIFO
Processes are scheduled in the Real-Time (RT)
scheduling class, according to the First-In-First-Out
(FIFO) policy. Processes scheduled to this policy, if
not preempted by a higher priority or interrupted by a
signal, will proceed until completion.


SCHED_RR
Processes are scheduled in the Real-Time (RT)
scheduling class, according to the Round-Robin (RR)
policy. Processes scheduled to this policy, if not
preempted by a higher priority or interrupted by a
signal, will execute for a time period, returned by
sched_rr_get_interval(3C) or by the system.


SCHED_IA
Processes are scheduled according to the Inter-Active
Class (IA) policy as described in priocntl(2).


SCHED_FSS
Processes are scheduled according to the Fair-Share
Class (FSS) policy as described in priocntl(2).


SCHED_FX
Processes are scheduled according to the Fixed-
Priority Class (FX) policy as described in
priocntl(2).


The values of these constants are distinct.


Inclusion of the <sched.h> header will make visible symbols defined
in the header <time.h>.

SEE ALSO

priocntl(2), sched_get_priority_max(3C), sched_get_priority_min(3C),
sched_rr_get_interval(3C), time.h(3HEAD)

April 1, 2008 SCHED.H(3HEAD)