pthread_attr_setinheritsched, pthread_attr_getinheritsched — set/get inherit scheduler attribute in thread attributes object
#include <pthread.h>
int pthread_attr_setinheritsched( |
pthread_attr_t *attr, |
int inheritsched) ; |
int pthread_attr_getinheritsched( |
pthread_attr_t *attr, |
int *inheritsched) ; |
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Note |
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Compile and link with |
The pthread_attr_setinheritsched
() function
sets the inherit scheduler attribute of the thread attributes
object referred to by attr
to the value specified in
inheritsched
. The
inherit scheduler attribute determines whether a thread
created using the thread attributes object attr
will inherit its
scheduling attributes from the calling thread or whether it
will take them from attr
.
The following values may be specified in inheritsched
:
PTHREAD_INHERIT_SCHED
Threads that are created using attr
inherit scheduling
attributes from the creating thread; the scheduling
attributes in attr
are ignored.
PTHREAD_EXPLICIT_SCHED
Threads that are created using attr
take their
scheduling attributes from the values specified by the
attributes object.
The default setting of the inherit scheduler attribute in
a newly initialized thread attributes object is PTHREAD_INHERIT_SCHED
.
The pthread_attr_getinheritsched
() returns the
inherit scheduler attribute of the thread attributes object
attr
in the buffer
pointed to by inheritsched
.
pthread_attr_setinheritsched
() can fail
with the following error:
Invalid value in inheritsched
.
POSIX.1-2001 also documents an optional ENOTSUP error ("attempt was made to set
the attribute to an unsupported value") for pthread_attr_setinheritsched
().
As at glibc 2.8, if a thread attributes object is
initialized using pthread_attr_init(3), then
the scheduling policy of the attributes object is set to
SCHED_OTHER
and the scheduling
priority is set to 0. However, if the inherit scheduler
attribute is then set to PTHREAD_EXPLICIT_SCHED
, then a thread
created using the attribute object wrongly inherits its
scheduling attributes from the creating thread. This bug does
not occur if either the scheduling policy or scheduling
priority attribute is explicitly set in the thread attributes
object before calling pthread_create(3).
sched_setscheduler(2), pthread_attr_init(3), pthread_attr_setschedparam(3), pthread_attr_setschedpolicy(3), pthread_create(3), pthread_setschedparam(3), pthread_setschedprio(3), pthreads(7)