128 lines
3.4 KiB
Groff
128 lines
3.4 KiB
Groff
.\"
|
|
.\" Copyright 2002 Massachusetts Institute of Technology
|
|
.\"
|
|
.\" Permission to use, copy, modify, and distribute this software and
|
|
.\" its documentation for any purpose and without fee is hereby
|
|
.\" granted, provided that both the above copyright notice and this
|
|
.\" permission notice appear in all copies, that both the above
|
|
.\" copyright notice and this permission notice appear in all
|
|
.\" supporting documentation, and that the name of M.I.T. not be used
|
|
.\" in advertising or publicity pertaining to distribution of the
|
|
.\" software without specific, written prior permission. M.I.T. makes
|
|
.\" no representations about the suitability of this software for any
|
|
.\" purpose. It is provided "as is" without express or implied
|
|
.\" warranty.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
|
|
.\" ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
|
|
.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
|
.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
|
|
.\" SHALL M.I.T. 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.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd June 16, 2002
|
|
.Dt PSELECT 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm pselect
|
|
.Nd synchronous I/O multiplexing a la POSIX.1g
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In sys/select.h
|
|
.Ft int
|
|
.Fo pselect
|
|
.Fa "int nfds"
|
|
.Fa "fd_set * restrict readfds"
|
|
.Fa "fd_set * restrict writefds"
|
|
.Fa "fd_set * restrict exceptfds"
|
|
.Fa "const struct timespec * restrict timeout"
|
|
.Fa "const sigset_t * restrict newsigmask"
|
|
.Fc
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn pselect
|
|
function was introduced by
|
|
.St -p1003.1g-2000
|
|
as a slightly stronger version of
|
|
.Xr select 2 .
|
|
The
|
|
.Fa nfds , readfds , writefds ,
|
|
and
|
|
.Fa exceptfds
|
|
arguments are all identical to the analogous arguments of
|
|
.Fn select .
|
|
The
|
|
.Fa timeout
|
|
argument in
|
|
.Fn pselect
|
|
points to a
|
|
.Vt "const struct timespec"
|
|
rather than the (modifiable)
|
|
.Vt "struct timeval"
|
|
used by
|
|
.Fn select ;
|
|
as in
|
|
.Fn select ,
|
|
a null pointer may be passed to indicate that
|
|
.Fn pselect
|
|
should wait indefinitely.
|
|
Finally,
|
|
.Fa newsigmask
|
|
specifies a signal mask which is set while waiting for input.
|
|
When
|
|
.Fn pselect
|
|
returns, the original signal mask is restored.
|
|
.Pp
|
|
See
|
|
.Xr select 2
|
|
for a more detailed discussion of the semantics of this interface, and
|
|
for macros used to manipulate the
|
|
.Vt "fd_set"
|
|
data type.
|
|
.Sh IMPLEMENTATION NOTES
|
|
The
|
|
.Fn pselect
|
|
function is implemented in the C library as a wrapper around
|
|
.Fn select .
|
|
.Sh RETURN VALUES
|
|
The
|
|
.Fn pselect
|
|
function returns the same values and under the same conditions as
|
|
.Fn select .
|
|
.Sh ERRORS
|
|
The
|
|
.Fn pselect
|
|
function may fail for any of the reasons documented for
|
|
.Xr select 2
|
|
and (if a signal mask is provided)
|
|
.Xr sigprocmask 2 .
|
|
.Sh SEE ALSO
|
|
.Xr kqueue 2 ,
|
|
.Xr poll 2 ,
|
|
.Xr select 2 ,
|
|
.Xr sigprocmask 2
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn pselect
|
|
function conforms to
|
|
.St -p1003.1-2001 .
|
|
.Sh HISTORY
|
|
The
|
|
.Fn pselect
|
|
function first appeared in
|
|
.Fx 5.0 .
|
|
.Sh AUTHORS
|
|
The
|
|
.Fn pselect
|
|
function and this manual page were written by
|
|
.An Garrett Wollman Aq wollman@FreeBSD.org .
|