.\" Copyright (c) 2004-2007 Apple Inc. All rights reserved.
.Dd December 31, 2007
.Dt PTHREAD_ATTR 3
.Os
.Sh NAME
.Nm pthread_attr_getinheritsched ,
.Nm pthread_attr_setinheritsched
.Nd thread attribute operations
.Sh SYNOPSIS
.Fd #include <pthread.h>
.Ft int
.Fo pthread_attr_getinheritsched
.Fa "const pthread_attr_t *restrict attr"
.Fa "int *restrict inheritsched"
.Fc
.Ft int
.Fo pthread_attr_setinheritsched
.Fa "pthread_attr_t *attr"
.Fa "int inheritsched"
.Fc
.Sh DESCRIPTION
Thread attributes are used to specify parameters to
.Fn pthread_create .
One attribute object can be used in multiple calls to
.Fn pthread_create ,
with or without modifications between calls.
.Pp
One of the thread attributes of interest is the "inheritsched" attribute. This attribute
controls the scheduling policy and related attributes of the newly created thread. The values of the 
"inheritsched" attribute can be either PTHREAD_INHERIT_SCHED or PTHREAD_EXPLICIT_SCHED.
.Pp
PTHREAD_INHERIT_SCHED
.Pp
	Indicates that the newly created thread should inherit all it's scheduling related attributes from it's creating
thread. It ignores the values of the relevant attributes within the
.Fa attr
argument.
.Pp
PTHREAD_EXPLICIT_SCHED
.Pp	
	Indicates that the newly created thread should set it's scheduling related attributes based on 
.Fa attr
argument.
.Pp
The
.Fn pthread_attr_setinheritsched
functions set the "inheritsched" attribute within the
.Fa attr 
argument to the desired value.
.Pp
The
.Fn pthread_attr_getinheritsched
functions copy the value of the "inheritsched" attribute to the location pointed to by the second function parameter.
.Sh RETURN VALUES
If successful, these functions return 0.
Otherwise, an error number is returned to indicate the error.
.Sh ERRORS
.Pp
.Fn pthread_attr_getinheritsched
will fail if:
.Bl -tag -width Er
.\" ========
.It Bq Er EINVAL
Invalid value for
.Fa attr .
.El
.Pp
.Fn pthread_attr_setinheritsched
will fail if:
.Bl -tag -width Er
.\" ========
.It Bq Er EINVAL
Invalid value for
.Fa attr .
.El
.Sh BUGS
.Pp
The "inheritsched" attribute has no effect on Darwin.  It is provided for compatibility only.
.Sh SEE ALSO
.Xr pthread_create 3 ,
.Xr pthread_attr_init 3 ,
.Xr pthread_attr_setschedparam 3
.Sh STANDARDS
.Pp
.Fn pthread_attr_setinheritsched ,
.Fn pthread_attr_getinheritsched 
conform to
.St -susv2