1*eabc0478Schristos /* $NetBSD: once.c,v 1.2 2024/08/18 20:47:16 christos Exp $ */ 2897be3a4Schristos 3897be3a4Schristos /* 4897be3a4Schristos * Copyright (C) 2004, 2007 Internet Systems Consortium, Inc. ("ISC") 5897be3a4Schristos * Copyright (C) 1999-2001 Internet Software Consortium. 6897be3a4Schristos * 7897be3a4Schristos * Permission to use, copy, modify, and/or distribute this software for any 8897be3a4Schristos * purpose with or without fee is hereby granted, provided that the above 9897be3a4Schristos * copyright notice and this permission notice appear in all copies. 10897be3a4Schristos * 11897be3a4Schristos * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 12897be3a4Schristos * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 13897be3a4Schristos * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 14897be3a4Schristos * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 15897be3a4Schristos * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 16897be3a4Schristos * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 17897be3a4Schristos * PERFORMANCE OF THIS SOFTWARE. 18897be3a4Schristos */ 19897be3a4Schristos 20897be3a4Schristos /* Id: once.c,v 1.12 2007/06/18 23:47:49 tbox Exp */ 21897be3a4Schristos 22897be3a4Schristos /* Principal Authors: DCL */ 23897be3a4Schristos 24897be3a4Schristos #include <config.h> 25897be3a4Schristos 26897be3a4Schristos #include <windows.h> 27897be3a4Schristos 28897be3a4Schristos #include <isc/once.h> 29897be3a4Schristos #include <isc/assertions.h> 30897be3a4Schristos #include <isc/util.h> 31897be3a4Schristos 32897be3a4Schristos isc_result_t 33897be3a4Schristos isc_once_do(isc_once_t *controller, void(*function)(void)) { 34897be3a4Schristos REQUIRE(controller != NULL && function != NULL); 35897be3a4Schristos 36897be3a4Schristos if (controller->status == ISC_ONCE_INIT_NEEDED) { 37897be3a4Schristos 38897be3a4Schristos if (InterlockedDecrement(&controller->counter) == 0) { 39897be3a4Schristos if (controller->status == ISC_ONCE_INIT_NEEDED) { 40897be3a4Schristos function(); 41897be3a4Schristos controller->status = ISC_ONCE_INIT_DONE; 42897be3a4Schristos } 43897be3a4Schristos } else { 44897be3a4Schristos while (controller->status == ISC_ONCE_INIT_NEEDED) { 45897be3a4Schristos /* 46897be3a4Schristos * Sleep(0) indicates that this thread 47897be3a4Schristos * should be suspended to allow other 48897be3a4Schristos * waiting threads to execute. 49897be3a4Schristos */ 50897be3a4Schristos Sleep(0); 51897be3a4Schristos } 52897be3a4Schristos } 53897be3a4Schristos } 54897be3a4Schristos 55897be3a4Schristos return (ISC_R_SUCCESS); 56897be3a4Schristos } 57