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   sched_setparam.3p    ( 3 )

установить параметры расписания (РЕАЛЬНОЕ ВРЕМЯ) (set scheduling parameters (REALTIME))

Пролог (Prolog)

This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

Имя (Name)

sched_setparam — set scheduling parameters (REALTIME)

Синопсис (Synopsis)

#include <sched.h>

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


Описание (Description)

The sched_setparam() function shall set the scheduling parameters
       of the process specified by pid to the values specified by the
       sched_param structure pointed to by param.  The value of the
       sched_priority member in the sched_param structure shall be any
       integer within the inclusive priority range for the current
       scheduling policy of the process specified by pid.  Higher
       numerical values for the priority represent higher priorities.
       If the value of pid is negative, the behavior of the
       sched_setparam() function is unspecified.

If a process specified by pid exists, and if the calling process has permission, the scheduling parameters shall be set for the process whose process ID is equal to pid.

If pid is zero, the scheduling parameters shall be set for the calling process.

The conditions under which one process has permission to change the scheduling parameters of another process are implementation- defined.

Implementations may require the requesting process to have appropriate privileges to set its own scheduling parameters or those of another process.

See Scheduling Policies for a description on how this function affects the scheduling of the threads within the target process.

If the current scheduling policy for the target process is not SCHED_FIFO, SCHED_RR, or SCHED_SPORADIC, the result is implementation-defined; this case includes the SCHED_OTHER policy.

The specified sched_ss_repl_period shall be greater than or equal to the specified sched_ss_init_budget for the function to succeed; if it is not, then the function shall fail.

The value of sched_ss_max_repl shall be within the inclusive range [1,{SS_REPL_MAX}] for the function to succeed; if not, the function shall fail. It is unspecified whether the sched_ss_repl_period and sched_ss_init_budget values are stored as provided by this function or are rounded to align with the resolution of the clock being used.

This function is not atomic with respect to other threads in the process. Threads may continue to execute while this function call is in the process of changing the scheduling policy for the underlying kernel-scheduled entities used by the process contention scope threads.


Возвращаемое значение (Return value)

If successful, the sched_setparam() function shall return zero.

If the call to sched_setparam() is unsuccessful, the priority shall remain unchanged, and the function shall return a value of -1 and set errno to indicate the error.


Ошибки (Error)

The sched_setparam() function shall fail if:

EINVAL One or more of the requested scheduling parameters is outside the range defined for the scheduling policy of the specified pid.

EPERM The requesting process does not have permission to set the scheduling parameters for the specified process, or does not have appropriate privileges to invoke sched_setparam().

ESRCH No process can be found corresponding to that specified by pid.

The following sections are informative.


Примеры (Examples)

None.

Использование в приложениях (Application usage)

None.

Обоснование (Rationale)

None.

Будущие направления (Future directions)

None.

Смотри также (See also)

Scheduling Policies, sched_getparam(3p), sched_getscheduler(3p),
       sched_setscheduler(3p)

The Base Definitions volume of POSIX.1‐2017, sched.h(0p)