NAME

       pthread_attr_setinheritsched,  pthread_attr_getinheritsched  -  set/get  inherit-scheduler  attribute  in
       thread attributes object

LIBRARY

       POSIX threads library (libpthread, -lpthread)

SYNOPSIS

       #include <pthread.h>

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

DESCRIPTION

       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  scheduling  attributes are affected by the inherit-scheduler attribute: scheduling policy
       (pthread_attr_setschedpolicy(3)), scheduling  priority  (pthread_attr_setschedparam(3)),  and  contention
       scope (pthread_attr_setscope(3)).

       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.

RETURN VALUE

       On success, these functions return 0; on error, they return a nonzero error number.

ERRORS

       pthread_attr_setinheritsched() can fail with the following error:

       EINVAL Invalid value in inheritsched.

       POSIX.1  also  documents  an  optional  ENOTSUP  error  ("attempt  was  made  to  set the attribute to an
       unsupported value") for pthread_attr_setinheritsched().

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       ┌──────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                                                     │ Attribute     │ Value   │
       ├──────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │pthread_attr_setinheritsched(), pthread_attr_getinheritsched()                │ Thread safety │ MT-Safe │
       └──────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       POSIX.1-2008.

HISTORY

       glibc 2.0.  POSIX.1-2001.

BUGS

       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).

EXAMPLES

       See pthread_setschedparam(3).

SEE ALSO

       pthread_attr_init(3), pthread_attr_setschedparam(3), pthread_attr_setschedpolicy(3),
       pthread_attr_setscope(3), pthread_create(3), pthread_setschedparam(3), pthread_setschedprio(3),
       pthreads(7), sched(7)