1 /* 2 * Copyright (C) 2004, 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.c,v 1.12 2007/06/18 23:47:49 tbox Exp $ */ 19 20 /* Principal Authors: DCL */ 21 22 #include <config.h> 23 24 #include <windows.h> 25 26 #include <isc/once.h> 27 #include <isc/assertions.h> 28 #include <isc/util.h> 29 30 isc_result_t 31 isc_once_do(isc_once_t *controller, void(*function)(void)) { 32 REQUIRE(controller != NULL && function != NULL); 33 34 if (controller->status == ISC_ONCE_INIT_NEEDED) { 35 36 if (InterlockedDecrement(&controller->counter) == 0) { 37 if (controller->status == ISC_ONCE_INIT_NEEDED) { 38 function(); 39 controller->status = ISC_ONCE_INIT_DONE; 40 } 41 } else { 42 while (controller->status == ISC_ONCE_INIT_NEEDED) { 43 /* 44 * Sleep(0) indicates that this thread 45 * should be suspended to allow other 46 * waiting threads to execute. 47 */ 48 Sleep(0); 49 } 50 } 51 } 52 53 return (ISC_R_SUCCESS); 54 } 55