內容簡介

#include <sched.h>

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

int sched_getparam(pid_t pid, struct sched_param *param);

struct sched_param { ... int sched_priority; ... };

描述

sched_setparam() sets the scheduling parameters associated with the scheduling policy for the process identified by pid. If pid is zero, then the parameters of the current process are set. The interpretation of the parameter param depends on the scheduling policy of the process identified by pid. See sched_setscheduler(2) for a description of the scheduling policies supported under Linux.

sched_getparam() retrieves the scheduling parameters for the process identified by pid. If pid is zero, then the parameters of the current process are retrieved.

sched_setparam() checks the validity of param for the scheduling policy of the process. The parameter param->sched_priority must lie within the range given bysched_get_priority_min(2) and sched_get_priority_max(2).

For a discussion of the privileges and resource limits related to scheduling priority and policy, see sched_setscheduler(2).

POSIX systems on which sched_setparam() and sched_getparam() are available define_POSIX_PRIORITY_SCHEDULING in <unistd.h>.

返回值

On success, sched_setparam() and sched_getparam() return 0. On error, -1 is returned, and errno is set appropriately.

錯誤

標籤	描述
EINVAL	The parameter param does not make sense for the current scheduling policy.
EPERM	The calling process does not have appropriate privileges (Linux: does not have the CAP_SYS_NICE capability).
ESRCH	The process whose ID is pid could not be found.

遵循於

POSIX.1-2001.

另請參閱

Programming for the real world - POSIX.4 by Bill O. Gallmeister, O’Reilly & Associates, Inc., ISBN 1-56592-074-0