1135446Strhodes/*
2193149Sdougb * Copyright (C) 2004, 2007  Internet Systems Consortium, Inc. ("ISC")
3135446Strhodes * Copyright (C) 2000, 2001  Internet Software Consortium.
4135446Strhodes *
5193149Sdougb * Permission to use, copy, modify, and/or distribute this software for any
6135446Strhodes * purpose with or without fee is hereby granted, provided that the above
7135446Strhodes * copyright notice and this permission notice appear in all copies.
8135446Strhodes *
9135446Strhodes * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10135446Strhodes * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11135446Strhodes * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12135446Strhodes * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13135446Strhodes * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14135446Strhodes * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15135446Strhodes * PERFORMANCE OF THIS SOFTWARE.
16135446Strhodes */
17135446Strhodes
18234010Sdougb/* $Id: once.h,v 1.6 2007/06/19 23:47:18 tbox Exp $ */
19135446Strhodes
20135446Strhodes#ifndef ISC_ONCE_H
21135446Strhodes#define ISC_ONCE_H 1
22135446Strhodes
23135446Strhodes#include <isc/result.h>
24135446Strhodes
25135446Strhodestypedef isc_boolean_t isc_once_t;
26135446Strhodes
27135446Strhodes#define ISC_ONCE_INIT ISC_FALSE
28135446Strhodes
29135446Strhodes#define isc_once_do(op, f) \
30135446Strhodes	(!*(op) ? (f(), *(op) = ISC_TRUE, ISC_R_SUCCESS) : ISC_R_SUCCESS)
31135446Strhodes
32135446Strhodes#endif /* ISC_ONCE_H */
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