once.h revision 290001 
1/*
2 * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2001  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: once.h,v 1.13 2007/06/19 23:47:18 tbox Exp $ */
19
20#ifndef ISC_ONCE_H
21#define ISC_ONCE_H 1
22
23/*! \file */
24
25#include <pthread.h>
26
27#include <isc/platform.h>
28#include <isc/result.h>
29
30typedef pthread_once_t isc_once_t;
31
32#ifdef ISC_PLATFORM_BRACEPTHREADONCEINIT
33/*!
34 * This accomodates systems that define PTHRAD_ONCE_INIT improperly.
35 */
36#define ISC_ONCE_INIT { PTHREAD_ONCE_INIT }
37#else
38/*!
39 * This is the usual case.
40 */
41#define ISC_ONCE_INIT PTHREAD_ONCE_INIT
42#endif
43
44/* XXX We could do fancier error handling... */
45
46#define isc_once_do(op, f) \
47	((pthread_once((op), (f)) == 0) ? \
48	 ISC_R_SUCCESS : ISC_R_UNEXPECTED)
49
50#endif /* ISC_ONCE_H */
51