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)