NetBSD/lib/libpthread/pthread_attr.3

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.\" $NetBSD: pthread_attr.3,v 1.10 2009/04/11 16:51:39 wiz Exp $
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.\" Copyright (C) 2000 Jason Evans <jasone@FreeBSD.org>.
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.\" $FreeBSD: src/lib/libpthread/man/pthread_attr.3,v 1.11 2002/09/16 19:29:28 mini Exp $
.Dd March 21, 2007
.Dt PTHREAD_ATTR 3
.Os
.Sh NAME
.Nm pthread_attr_init ,
.Nm pthread_attr_destroy ,
.\" .Nm pthread_attr_setstacksize ,
.\" .Nm pthread_attr_getstacksize ,
.\" .Nm pthread_attr_setguardsize ,
.\" .Nm pthread_attr_getguardsize ,
.\" .Nm pthread_attr_setstackaddr ,
.\" .Nm pthread_attr_getstackaddr ,
.Nm pthread_attr_setdetachstate ,
.Nm pthread_attr_getdetachstate ,
.\" .Nm pthread_attr_setinheritsched ,
.\" .Nm pthread_attr_getinheritsched ,
.Nm pthread_attr_setschedparam ,
.Nm pthread_attr_getschedparam
.\" .Nm pthread_attr_setschedpolicy ,
.\" .Nm pthread_attr_getschedpolicy ,
.\" .Nm pthread_attr_setscope ,
.\" .Nm pthread_attr_getscope
.Nd thread attribute operations
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_attr_init "pthread_attr_t *attr"
.Ft int
.Fn pthread_attr_destroy "pthread_attr_t *attr"
.\" .Ft int
.\" .Fn pthread_attr_setstacksize "pthread_attr_t *attr" "size_t stacksize"
.\" .Ft int
.\" .Fn pthread_attr_getstacksize "const pthread_attr_t * restrict attr" "size_t * restrict stacksize"
.\" .Ft int
.\" .Fn pthread_attr_setguardsize "pthread_attr_t *attr" "size_t guardsize"
.\" .Ft int
.\" .Fn pthread_attr_getguardsize "const pthread_attr_t * restrict attr" "size_t * restrict guardsize"
.\" .Ft int
.\" .Fn pthread_attr_setstackaddr "pthread_attr_t *attr" "void *stackaddr"
.\" .Ft int
.\" .Fn pthread_attr_getstackaddr "const pthread_attr_t * restrict attr" "void ** restrict stackaddr"
.Ft int
.Fn pthread_attr_setdetachstate "pthread_attr_t *attr" "int detachstate"
.Ft int
.Fn pthread_attr_getdetachstate "const pthread_attr_t *attr" "int *detachstate"
.\" .Ft int
.\" .Fn pthread_attr_setinheritsched "pthread_attr_t *attr" "int inheritsched"
.\" .Ft int
.\" .Fn pthread_attr_getinheritsched "const pthread_attr_t * restrict attr" "int * restrict inheritsched"
.Ft int
.Fn pthread_attr_setschedparam "pthread_attr_t * restrict attr" "const struct sched_param * restrict param"
.Ft int
.Fn pthread_attr_getschedparam "const pthread_attr_t * restrict attr" "struct sched_param * restrict param"
.\" .Ft int
.\" .Fn pthread_attr_setschedpolicy "pthread_attr_t *attr" "int policy"
.\" .Ft int
.\" .Fn pthread_attr_getschedpolicy "const pthread_attr_t * restrict attr" "int * restrict policy"
.\" .Ft int
.\" .Fn pthread_attr_setscope "pthread_attr_t *attr" "int contentionscope"
.\" .Ft int
.\" .Fn pthread_attr_getscope "const pthread_attr_t * restrict attr" "int * restrict contentionscope"
.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
The
.Fn pthread_attr_init
function initializes
.Fa attr
with all the default thread attributes.
.Pp
The
.Fn pthread_attr_destroy
function destroys
.Fa attr .
.Pp
The
.Fn pthread_attr_set*
functions set the attribute that corresponds to each function name.
.Pp
The
.Fn pthread_attr_get*
functions copy the value of the attribute that corresponds to each function name
to the location pointed to by the second function parameter.
.Pp
The attribute parameters for the
.Fn pthread_attr_setdetachstate
and
.Fn pthread_attr_getdetachstate
are mutually exclusive and must be one of:
.Bl -tag -width xxxxxxxx
.It Dv PTHREAD_CREATE_JOINABLE
The threads must explicitly be waited for using the
.Fn pthread_join
function once they exit for their status to be received and their resources
to be freed.
This is the default.
.It Dv PTHREAD_CREATE_DETACHED
The thread's resources will automatically be freed once the thread exits,
and the thread will not be joined.
.El
.Sh RETURN VALUES
If successful, these functions return 0.
Otherwise, an error number is returned to indicate the error.
.Sh ERRORS
.Fn pthread_attr_init
shall fail if:
.Bl -tag -width Er
.It Bq Er ENOMEM
Out of memory.
.El
.Pp
.Fn pthread_attr_destroy
may fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa attr
is invalid.
.El
.Pp
.\" .Fn pthread_attr_setstacksize
.\" may fail if:
.\" .Bl -tag -width Er
.\" .It Bq Er EINVAL
.\" .Fa stacksize
.\" is less than
.\" .Dv PTHREAD_STACK_MIN .
.\" .El
.\" .Pp
.Fn pthread_attr_setdetachstate
shall fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa detachstate
is invalid.
.El
.Pp
.\" Fn pthread_attr_setinheritsched
.\" may fail if:
.\" .Bl -tag -width Er
.\" .It Bq Er EINVAL
.\" Invalid value for
.\" .Fa attr .
.\" .El
.\" .Pp
.Fn pthread_attr_setschedparam
may fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa attr
is invalid.
.It Bq Er ENOTSUP
The value specified by
.Fa param
is invalid.
.El
.\" .Pp
.\" .Fn pthread_attr_setschedpolicy
.\" may fail if:
.\" .Bl -tag -width Er
.\" .It Bq Er EINVAL
.\" Invalid value for
.\" .Fa attr .
.\" .It Bq Er ENOTSUP
.\" Invalid or unsupported value for
.\" .Fa policy .
.\" .El
.\" .Pp
.\" .Fn pthread_attr_setscope
.\" may fail if:
.\" .Bl -tag -width Er
.\" .It Bq Er EINVAL
.\" Invalid value for
.\" .Fa attr .
.\" .It Bq Er ENOTSUP
.\" Invalid or unsupported value for
.\" .Fa contentionscope .
.\" .El
.Sh SEE ALSO
.Xr pthread_create 3 ,
.Xr pthread_join 3
.Sh STANDARDS
.Fn pthread_attr_init ,
.Fn pthread_attr_destroy ,
.\" .Fn pthread_attr_setstacksize ,
.\" .Fn pthread_attr_getstacksize ,
.\" .Fn pthread_attr_setstackaddr ,
.\" .Fn pthread_attr_getstackaddr ,
.Fn pthread_attr_setdetachstate ,
.Fn pthread_attr_getdetachstate ,
.\" .Fn pthread_attr_setinheritsched ,
.\" .Fn pthread_attr_getinheritsched ,
.\" .Fn pthread_attr_setschedparam ,
.Fn pthread_attr_setschedparam ,
and
.Fn pthread_attr_getschedparam
.\" .Fn pthread_attr_setschedpolicy ,
.\" .Fn pthread_attr_getschedpolicy ,
.\" .Fn pthread_attr_setscope ,
.\" and
.\" .Fn pthread_attr_getscope
conform to
.St -p1003.1-96 .