NetBSD/lib/libpthread/pthread_attr_get_np.3

101 lines
3.2 KiB
Groff

.\" $NetBSD: pthread_attr_get_np.3,v 1.3 2010/07/07 09:54:07 wiz Exp $
.\"
.\" Copyright (c) 2010 Jukka Ruohonen <jruohonen@iki.fi>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\"
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd July 6, 2010
.Dt PTHREAD_ATTR_GET_NP 3
.Os
.Sh NAME
.Nm pthread_attr_get_np
.Nd get attributes of existing thread
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_attr_get_np "pthread_t thread" "pthread_attr_t *attr"
.Sh DESCRIPTION
The
.Fn pthread_attr_get_np
function can be used to retrieve attributes of a running
.Fa thread .
The result is stored to
.Fa attr ,
which should be initialized prior to the call by using
.Xr pthread_attr_init 3 .
.Pp
Most fields of
.Fa attr
are the same ones provided during thread creation time as a parameter to
.Xr pthread_create 3 .
The exceptions include:
.Bl -bullet -offset indent
.It
The detach state -- a joinable thread
may have detached itself after the creation.
.It
The guard size, which may vary if the application
has allocated its own thread stack.
.It
The stack address and size;
.Fn pthread_attr_get_np
will always return the thread's real stack address and size,
regardless of the values in the original attributes structure.
.El
.Pp
The returned
.Vt pthread_attr_t
structure is supposed to be used in conjunction with the
.Fn pthread_attr_get*
functions to retrieve individual values from the structure.
When the returned
.Fa attr
is no longer needed, it should be destroyed by using
.Xr pthread_attr_destroy 3 .
.Sh RETURN VALUES
Upon successful completion,
.Fn pthread_attr_get_np
returns 0.
Otherwise an error number is returned to indicate the error.
.Sh COMPATIBILITY
The
.Fn pthread_attr_get_np
function is a non-standard extension.
.Sh ERRORS
The
.Fn pthread_attr_get_np
function will fail if:
.Bl -tag -width Er
.It Bq Er ENOMEM
Insufficient memory.
.It Bq Er ESRCH
Non-existent
.Fa thread .
.El
.Sh SEE ALSO
.Xr pthread 3 ,
.Xr pthread_attr 3