54 lines
1.9 KiB
C
54 lines
1.9 KiB
C
|
/* $NetBSD: once.h,v 1.5 2008/10/09 10:48:21 pooka Exp $ */
|
||
|
|
|
||
|
|
/*-
|
||
|
|
* Copyright (c)2005 YAMAMOTO Takashi,
|
||
|
|
* Copyright (c)2008 Antti Kantee,
|
||
|
|
* 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef _SYS_ONCE_H_
|
||
|
|
#define _SYS_ONCE_H_
|
||
|
|
|
||
|
|
typedef struct {
|
||
|
|
unsigned o_status;
|
||
|
|
int o_error;
|
||
|
|
#define ONCE_VIRGIN 0
|
||
|
|
#define ONCE_RUNNING 1
|
||
|
|
#define ONCE_DONE 2
|
||
|
|
} once_t;
|
||
|
|
|
||
|
|
void once_init(void);
|
||
|
|
int _run_once(once_t *, int (*)(void));
|
||
|
|
|
||
|
|
#define ONCE_DECL(o) \
|
||
|
|
once_t (o) = { \
|
||
|
|
.o_status = 0, \
|
||
|
|
};
|
||
|
|
|
||
|
|
#define RUN_ONCE(o, fn) \
|
||
|
|
(__predict_true((o)->o_status == ONCE_DONE) ? \
|
||
|
|
((o)->o_error) : _run_once((o), (fn)))
|
||
|
|
|
||
|
|
#endif /* _SYS_ONCE_H_ */
|