HardenedBSD/share/man/man3/pthread_once.3
Julian Elischer 0f7d684755 Submitted by: John Birrell <cimaxp1!jb@werple.net.au>
Here are the diffs for libc_r to get it one step closer to P1003.1c
These make most of the thread/mutex/condvar structures opaque to the
user. There are three functions which have been renamed with _np
suffixes because they are extensions to P1003.1c (I did them for JAVA,
which needs to suspend/resume threads and also start threads suspended).

I've created a new header (pthread_np.h) for the non-POSIX stuff.

The egrep tags stuff in /usr/src/lib/libc_r/Makefile that I uncommented
doesn't work. I think its best to delete it. I don't think libc_r needs
tags anyway, 'cause most of the source is in libc which does have tags.

also:

Here's the first batch of man pages for the thread functions.
The diff to /usr/src/lib/libc_r/Makefile removes some stuff that was
inherited from /usr/src/lib/libc/Makefile that should only be done with
libc.

also:

I should have sent this diff with the pthread(3) man page.
It allows people to type

make -DWANT_LIBC_R world

to get libc_r built with the rest of the world. I put this in the
pthread(3) man page.  The default is still not to build libc_r.


also:
The diff attached adds a pthread(3) man page to /usr/src/share/man/man3.
The idea is that without libc_r installed, this man page will give people
enough info to know that they have to build libc_r.
1996-08-20 08:22:01 +00:00

101 lines
3.2 KiB
Groff

.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
.\" 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.
.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed by John Birrell.
.\" 4. Neither the name of the author nor the names of any co-contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL 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 REGENTS 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 April 4, 1996
.Dt PTHREAD_ONCE 3
.Os BSD 4
.Sh NAME
.Nm pthread_once
.Nd dynamic package initialization
.Sh SYNOPSIS
.Fd #include <pthread.h>
.Pp
pthread_once
.Fa once_control
= PTHREAD_ONCE_INIT;
.Ft int
.Fn pthread_once "pthread_once_t *once_control" "void *(*init_routine)(void)"
.Sh DESCRIPTION
The first call to
.Fn pthread_once
by any thread in a process, with a given
.Fa once_control ,
will call the
.Fn init_routine
with no arguments. Subsequent calls to
.Fn pthread_once
with the same
.Fa once_control
will not call the
.Fn init_routine .
On return from
.Fn pthread_once ,
it is guaranteed that
.Fn init_routine
has completed. The
.Fa once_control
parameter is used to determine whether the associated initialization
routine has been called.
.Pp
The function
.Fn pthread_once
is not a cancellation point. However, if
.Fn init_routine
is a cancellation point and is cancelled, the effect on
.Fa once_control is as if
.Fn pthread_once
was never called.
.Pp
The constant
.Fa PTHREAD_ONCE_INIT
is defined by header
.Aq Pa pthread.h .
.Pp
The behavior of
.Fn pthread_once
is undefined if
.Fa once_control
has automatic storage duration or is not initialized by
.Fa PTHREAD_ONCE_INIT .
.Pp
.Sh RETURN VALUES
If successful, the
.Fn pthread_once
function will return zero. Otherwise an error number will be returned to
indicate the error.
.Sh ERRORS
None.
.Pp
.Sh STANDARDS
.Fn pthread_once
is expected to conform to IEEE
.Pq Dq Tn POSIX
Std 1003.1c when it is published.