freebsd-dev/lib/libc/gen/_once_stub.c
John Baldwin 4e1fc19cea Revert the previous change to pthread_once() stub in libc. It is actually
a feature that libstdc++ depends on to simulate the behavior of libc's
internal '__isthreaded' variable.  One benefit of this is that _libc_once()
is now private to _once_stub.c.

Requested by:	kan
2009-11-20 20:43:34 +00:00

65 lines
2.4 KiB
C

/*-
* Copyright (c) 2009 Advanced Computing Technologies LLC
* Written by: John H. Baldwin <jhb@FreeBSD.org>
* 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 AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <pthread.h>
#include "un-namespace.h"
#include "libc_private.h"
/* This implements pthread_once() for the single-threaded case. */
static int
_libc_once(pthread_once_t *once_control, void (*init_routine)(void))
{
if (once_control->state == PTHREAD_DONE_INIT)
return (0);
init_routine();
once_control->state = PTHREAD_DONE_INIT;
return (0);
}
/*
* This is the internal interface provided to libc. It will use
* pthread_once() from the threading library in a multi-threaded
* process and _libc_once() for a single-threaded library. Because
* _libc_once() uses the same ABI for the values in the pthread_once_t
* structure as the threading library, it is safe for a process to
* switch from _libc_once() to pthread_once() when threading is
* enabled.
*/
int
_once(pthread_once_t *once_control, void (*init_routine)(void))
{
if (__isthreaded)
return (_pthread_once(once_control, init_routine));
return (_libc_once(once_control, init_routine));
}