glibc/nptl/pthread_once.c

54 lines
1.6 KiB
C

/* Copyright (C) 2002, 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include "pthreadP.h"
#include <lowlevellock.h>
static int once_lock = LLL_LOCK_INITIALIZER;
int
__pthread_once (once_control, init_routine)
pthread_once_t *once_control;
void (*init_routine) (void);
{
/* XXX Depending on whether the LOCK_IN_ONCE_T is defined use a
global lock variable or one which is part of the pthread_once_t
object. */
if (*once_control == PTHREAD_ONCE_INIT)
{
lll_lock (once_lock, LLL_PRIVATE);
/* XXX This implementation is not complete. It doesn't take
cancelation and fork into account. */
if (*once_control == PTHREAD_ONCE_INIT)
{
init_routine ();
*once_control = !PTHREAD_ONCE_INIT;
}
lll_unlock (once_lock, LLL_PRIVATE);
}
return 0;
}
strong_alias (__pthread_once, pthread_once)