PTHREAD_ATTR_SETINHERITSCHELinux Programmer's MPTHREAD_ATTR_SETINHERITSCHED(3)



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

SYNOPSIS
       #include <pthread.h>

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

       Compile and link with -pthread.

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-sched-
       uler  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 ini-
       tialized 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_setinher-
       itsched().

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

       +--------------------------------+---------------+---------+
       |Interface			| Attribute	| Value	  |
       +--------------------------------+---------------+---------+
       |pthread_attr_setinheritsched(), | Thread safety | MT-Safe |
       |pthread_attr_getinheritsched()	|		|	  |
       +--------------------------------+---------------+---------+
CONFORMING TO
       POSIX.1-2001, POSIX.1-2008.

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).

EXAMPLE
       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)

COLOPHON
       This page is part of release 4.10 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.



Linux				  2015-08-08   PTHREAD_ATTR_SETINHERITSCHED(3)