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
isc_once_do(isc_once_t * controller,void (* function)(void))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