man/man3c/pthread_getschedparam.3c

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 PTHREAD_GETSCHEDPARAM 3C "Apr 1, 2008"
 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 policies 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(7). The affected scheduling parameter is the
sched_priority 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 specified 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 scheduling 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_setschedparam() 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 parameters
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(7) for descriptions of the following attributes:


ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Committed
MT-Level MT-Safe
Standard See standards(7).


 SEE ALSO

 pthread_attr_init (3C),  sched_get_priority_max (3C),  sched_get_priority_max (3C),  sched_get_priority_min (3C),  sched_getparam (3C),  sched_getscheduler (3C),  sched_setparam (3C),  sched_setscheduler (3C),  attributes (7),  pthreads (7),  standards (7)