_POSIX_PRIORITY_SCHEDULING

POSIX Priority Scheduling option. More...

Macros
#define	SCHED_OTHER   0
	Round-robin or other time-sharing scheduling (default).
#define	SCHED_FIFO   1
	First-in first-out (cooperative) scheduling policy.
#define	SCHED_RR   2
	Round-robin (preemptive, priority-based) scheduling policy.

Functions
int	sched_get_priority_min (int policy)
	Get the minimum priority value for a scheduling policy.
int	sched_get_priority_max (int policy)
	Get the maximum priority value for a scheduling policy.
int	sched_getparam (pid_t pid, struct sched_param *param)
	Get scheduling parameters for a process.
int	sched_getscheduler (pid_t pid)
	Get the scheduling policy of a process.
int	sched_setparam (pid_t pid, const struct sched_param *param)
	Set scheduling parameters for a process.
int	sched_setscheduler (pid_t pid, int policy, const struct sched_param *param)
	Set the scheduling policy and parameters of a process.
int	sched_rr_get_interval (pid_t pid, struct timespec *interval)
	Get the round-robin time quantum for a process.

Detailed Description

POSIX Priority Scheduling option.

Covers process scheduling in sched.h: sched_get_priority_min(), sched_get_priority_max(), sched_getparam(), sched_getscheduler(), sched_setparam(), sched_setscheduler(), and sched_rr_get_interval().

Macro Definition Documentation

SCHED_FIFO

#define SCHED_FIFO   1

First-in first-out (cooperative) scheduling policy.

Definition at line 36 of file sched.h.

SCHED_OTHER

#define SCHED_OTHER   0

Round-robin or other time-sharing scheduling (default).

May execute identically to SCHED_RR on this implementation.

Definition at line 33 of file sched.h.

SCHED_RR

#define SCHED_RR   2

Round-robin (preemptive, priority-based) scheduling policy.

Definition at line 39 of file sched.h.

Function Documentation

sched_get_priority_max()

int sched_get_priority_max

(

int

policy

)

Get the maximum priority value for a scheduling policy.

Parameters

policy

SCHED_FIFO, SCHED_RR, or SCHED_OTHER.

Returns

Maximum priority on success, or -1 with errno set on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_get_priority_max.html

sched_get_priority_min()

int sched_get_priority_min

(

int

policy

)

Get the minimum priority value for a scheduling policy.

Parameters

policy

SCHED_FIFO, SCHED_RR, or SCHED_OTHER.

Returns

Minimum priority on success, or -1 with errno set on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_get_priority_min.html

sched_getparam()

int sched_getparam	(	pid_t	pid,
		struct sched_param *	param
	)

ENOSYS

Get scheduling parameters for a process.

Parameters

pid	Process ID (0 = calling process).
param	Output: current scheduling parameters.

Returns

0 on success, or -1 with errno set on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_getparam.html

sched_getscheduler()

int sched_getscheduler

(

pid_t

pid

)

ENOSYS

Get the scheduling policy of a process.

Parameters

pid	Process ID (0 = calling process).

Returns

Scheduling policy (SCHED_FIFO, SCHED_RR, SCHED_OTHER), or -1 with errno set on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_getscheduler.html

sched_rr_get_interval()

int sched_rr_get_interval	(	pid_t	pid,
		struct timespec *	interval
	)

ENOSYS

Get the round-robin time quantum for a process.

Parameters

pid	Process ID (0 = calling process).
interval	Output: round-robin interval.

Returns

0 on success, or -1 with errno set on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_rr_get_interval.html

sched_setparam()

int sched_setparam	(	pid_t	pid,
		const struct sched_param *	param
	)

ENOSYS

Set scheduling parameters for a process.

Parameters

pid	Process ID (0 = calling process).
param	New scheduling parameters.

Returns

0 on success, or -1 with errno set on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_setparam.html

sched_setscheduler()

int sched_setscheduler	(	pid_t	pid,
		int	policy,
		const struct sched_param *	param
	)

ENOSYS

Set the scheduling policy and parameters of a process.

Parameters

pid	Process ID (0 = calling process).
policy	SCHED_FIFO, SCHED_RR, or SCHED_OTHER.
param	New scheduling parameters.

Returns

0 on success, or -1 with errno set on failure.

See also

https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_setscheduler.html