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)