pthread_attr_setschedparam Subroutine

Purpose

Sets the value of the schedparam attribute of a thread attributes object.

Library

Threads Library (libpthreads.a)

Syntax

#include <pthread.h>
#include <sys/sched.h>

int pthread_attr_setschedparam (attr, schedparam)
pthread_attr_t *attr;
const struct sched_param *schedparam;

Description

The pthread_attr_setschedparam subroutine sets the value of the schedparam attribute of the thread attributes object attr. The schedparam attribute specifies the scheduling parameters of a thread created with this attributes object. The sched_priority field of the sched_param structure contains the priority of the thread.

Note: The pthread.h header file must be the first included file of each source file using the threads library. Otherwise, the -D_THREAD_SAFE compilation flag should be used, or the cc_r compiler used. In this case, the flag is automatically set.

Parameters

Item	Description
attr	Specifies the thread attributes object.
schedparam	Points to where the scheduling parameters to set are stored. The `sched_priority` field must be in the range from 1 to 127, where 1 is the least favored priority, and 127 the most favored.

Return Values

Upon successful completion, 0 is returned. Otherwise, an error code is returned.

Error Codes

The pthread_attr_setschedparam subroutine is unsuccessful if the following is true:

Item	Description
EINVAL	The attr parameter is not valid.
ENOSYS	The priority scheduling POSIX option is not implemented.
ENOTSUP	The value of the schedparam attribute is not supported.