PTHREAD_GETSCHEDPARAM(3C)PTHREAD_GETSCHEDPARAM(3C)NAME
pthread_getschedparam, pthread_setschedparam - access dynamic thread
scheduling parameters
SYNOPSIS
cc -mt [ flag... ] file... -lpthread [ library... ]
#include <pthread.h>
int pthread_getschedparam(pthread_t thread, int *restrict policy,
struct sched_param *restrict param);
int pthread_setschedparam(pthread_t thread, int policy,
const struct sched_param *param);
DESCRIPTION
The pthread_getschedparam() and pthread_setschedparam() functions allow
the scheduling policy and scheduling parameters of individual threads
within a multithreaded process to be retrieved and set. Supported poli‐
cies are :
SCHED_OTHER
traditional time-sharing scheduling class
SCHED_FIFO
real-time class: run to completion
SCHED_RR
real-time class: round-robin
SCHED_IA
interactive time-sharing class
SCHED_FSS
fair-share scheduling class
SCHED_FX
fixed priority scheduling class
See pthreads(5). The affected scheduling parameter is the sched_prior‐
ity member of the sched_param structure.
The pthread_getschedparam() function retrieves the scheduling policy
and scheduling parameters for the thread whose thread ID is given by
thread and stores those values in policy and param, respectively. The
priority value returned from pthread_getschedparam() is the value spec‐
ified by the most recent pthread_setschedparam() or pthread_create()
call affecting the target thread, and does not reflect any temporary
adjustments to its priority as a result of any priority inheritance or
ceiling functions. The pthread_setschedparam() function sets the sched‐
uling policy and associated scheduling parameters for the thread whose
thread ID is given by thread to the policy and associated parameters
provided in policy and param, respectively.
If the pthread_setschedparam() function fails, no scheduling parameters
will be changed for the target thread.
RETURN VALUES
If successful, the pthread_getschedparam() and pthread_setschedparam()
functions return 0. Otherwise, an error number is returned to indicate
the error.
ERRORS
The pthread_getschedparam() and pthread_gsetschedparam() functions will
fail if:
ESRCH
The value specified by thread does not refer to an existing
thread.
The pthread_setschedparam() function will fail if:
EINVAL
The value specified by policy or one of the scheduling param‐
eters associated with the scheduling policy policy is
invalid.
EPERM
The caller does not have the appropriate permission to set
either the scheduling parameters or the scheduling policy of
the specified thread.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬───────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼───────────────────┤
│Interface Stability │ Committed │
├────────────────────┼───────────────────┤
│MT-Level │ MT-Safe │
├────────────────────┼───────────────────┤
│Standard │ See standards(5). │
└────────────────────┴───────────────────┘
SEE ALSOpthread_attr_init(3C), sched_getparam(3C), sched_get_prior‐
ity_max(3C)sched_get_priority_max(3C), sched_get_priority_min(3C),
sched_setparam(3C), sched_getscheduler(3C), sched_setscheduler(3C),
attributes(5), pthreads(5), standards(5)
Apr 1, 2008 PTHREAD_GETSCHEDPARAM(3C)
