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.
pthread_attr_setschedparam() can fail with the following error:
- EINVAL
- 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 |
pthread_attr_setschedparam (), pthread_attr_getschedparam () |
Thread safety |
MT-Safe |
POSIX.1-2001, POSIX.1-2008.
See
pthread_attr_setschedpolicy(3) for a list of the thread scheduling
policies supported on Linux.
See
pthread_setschedparam(3).
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)