1 /* $NetBSD: once.c,v 1.4 2014/12/10 04:38:01 christos Exp $ */ 2 3 /* 4 * Copyright (C) 2004, 2007 Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (C) 1999-2001 Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and/or distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 13 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 17 * PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 /* Id: once.c,v 1.12 2007/06/18 23:47:49 tbox Exp */ 21 22 /* Principal Authors: DCL */ 23 24 #include <config.h> 25 26 #include <windows.h> 27 28 #include <isc/once.h> 29 #include <isc/assertions.h> 30 #include <isc/util.h> 31 32 isc_result_t 33 isc_once_do(isc_once_t *controller, void(*function)(void)) { 34 REQUIRE(controller != NULL && function != NULL); 35 36 if (controller->status == ISC_ONCE_INIT_NEEDED) { 37 38 if (InterlockedDecrement(&controller->counter) == 0) { 39 if (controller->status == ISC_ONCE_INIT_NEEDED) { 40 function(); 41 controller->status = ISC_ONCE_INIT_DONE; 42 } 43 } else { 44 while (controller->status == ISC_ONCE_INIT_NEEDED) { 45 /* 46 * Sleep(0) indicates that this thread 47 * should be suspended to allow other 48 * waiting threads to execute. 49 */ 50 Sleep(0); 51 } 52 } 53 } 54 55 return (ISC_R_SUCCESS); 56 } 57