pthread_attr_setschedparam, pthread_attr_getschedparam - set/get scheduling parameter attributes in thread attributes object
POSIX threads library (libpthread
, -lpthread
)
#include <pthread.h>
int pthread_attr_setschedparam(pthread_attr_t *restrict attr,
const struct sched_param *restrict param);
int pthread_attr_getschedparam(const pthread_attr_t *restrict attr,
struct sched_param *restrict param);
The pthread_attr_setschedparam() function sets the
scheduling parameter attributes of the thread attributes object referred
to by attr
to the values specified in the buffer pointed to by
param
. These attributes determine the scheduling parameters of
a thread created using the thread attributes object attr
.
The pthread_attr_getschedparam() returns the
scheduling parameter attributes of the thread attributes object
attr
in the buffer pointed to by param
.
Scheduling parameters are maintained in the following structure:
struct sched_param {
int sched_priority; /* Scheduling priority */
};
As can be seen, only one scheduling parameter is supported. For details of the permitted ranges for scheduling priorities in each scheduling policy, see sched(7).
In order for the parameter setting made by
pthread_attr_setschedparam() to have effect when
calling pthread_create(3), the caller must use
pthread_attr_setinheritsched(3) to set the
inherit-scheduler attribute of the attributes object attr
to
PTHREAD_EXPLICIT_SCHED.
On success, these functions return 0; on error, they return a nonzero error number.
See pthread_setschedparam(3).
pthread_attr_setschedparam() can fail with the following error:
The priority specified in param
does not make sense for the
current scheduling policy of attr
.
POSIX.1 also documents an ENOTSUP error for pthread_attr_setschedparam(). This value is never returned on Linux (but portable and future-proof applications should nevertheless handle this error return value).
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
Thread safety | MT-Safe |
POSIX.1-2008.
POSIX.1-2001. glibc 2.0.
See pthread_attr_setschedpolicy(3) for a list of the thread scheduling policies supported on Linux.
sched_get_priority_min(2), pthread_attr_init(3), pthread_attr_setinheritsched(3), pthread_attr_setschedpolicy(3), pthread_create(3), pthread_setschedparam(3), pthread_setschedprio(3), pthreads(7), sched(7)