pthread_attr_getinheritsched¶

Synopsis¶

#include <pthread.h>

int pthread_attr_getinheritsched(const pthread_attr_t *restrict attr,
                                 int *restrict inheritsched);

int pthread_attr_setinheritsched(pthread_attr_t *attr,
                                 int inheritsched);

Status¶

Implemented

Conformance¶

IEEE Std 1003.1-2017

Description¶

The pthread_attr_getinheritsched() and pthread_attr_setinheritsched() functions, respectively, shall get and set the inheritsched attribute in the attr argument.

When the attributes objects are used by pthread_create(), the inheritsched attribute determines how the other scheduling attributes of the created thread shall be set.

The supported values of inheritsched shall be:

PTHREAD_INHERIT_SCHED - Specifies that the thread scheduling attributes shall be inherited from the creating thread, and the scheduling attributes in this attr argument shall be ignored.
PTHREAD_EXPLICIT_SCHED - Specifies that the thread scheduling attributes shall be set to the corresponding values from this attributes object.

The symbols PTHREAD_INHERIT_SCHED and PTHREAD_EXPLICIT_SCHED are defined in the <pthread.h> header. In Phoenix-RTOS the default value of the attribute is PTHREAD_EXPLICIT_SCHED.

The following thread scheduling attributes defined by POSIX.1-2017 are affected by the inheritsched attribute: scheduling policy (schedpolicy), scheduling parameters (schedparam), and scheduling contention scope (contentionscope). Phoenix-RTOS supports only the SCHED_RR policy and the PTHREAD_SCOPE_SYSTEM contention scope, so only the priority of the created thread depends on the inheritsched attribute.

The behavior is undefined if the value specified by the attr argument to pthread_attr_getinheritsched() or pthread_attr_setinheritsched() does not refer to an initialized thread attributes object.

Return value¶

If successful, the pthread_attr_getinheritsched() and pthread_attr_setinheritsched() functions shall return zero; otherwise, an error number shall be returned to indicate the error.

Errors¶

The pthread_attr_setinheritsched() function shall fail if:

ENOTSUP - An attempt was made to set the attribute to an unsupported value.

The pthread_attr_setinheritsched() function may fail if:

EINVAL - The value of inheritsched is not valid.

These functions shall not return an error code of EINTR.

POSIX deviations¶

No POSIX deviations discovered.