1 /* 2 * Copyright (C) 2004, 2007 Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (C) 2000, 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 1.6 2007/06/19 23:47:18 tbox Exp $ */ 19 20 #ifndef ISC_ONCE_H 21 #define ISC_ONCE_H 1 22 23 #include <isc/result.h> 24 25 typedef isc_boolean_t isc_once_t; 26 27 #define ISC_ONCE_INIT ISC_FALSE 28 29 #define isc_once_do(op, f) \ 30 (!*(op) ? (f(), *(op) = ISC_TRUE, ISC_R_SUCCESS) : ISC_R_SUCCESS) 31 32 #endif /* ISC_ONCE_H */ 33