once.c revision 15a44745412679c30a6d022733925af70a38b715
/*
* Copyright (C) 1999, 2000 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
* INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: once.c,v 1.4 2000/07/27 09:53:15 tale Exp $ */
/* Principal Authors: DCL */
#include <windows.h>
#include <isc/once.h>
#include <isc/assertions.h>
isc_result_t
isc_once_do(isc_once_t *controller, void(*function)(void))
{
REQUIRE(controller != NULL && function != NULL);
if (controller->status == ISC_ONCE_INIT_NEEDED) {
if (InterlockedDecrement(&controller->counter) == 0) {
if (controller->status == ISC_ONCE_INIT_NEEDED) {
function();
controller->status = ISC_ONCE_INIT_DONE;
}
} else {
while (controller->status == ISC_ONCE_INIT_NEEDED) {
/*
* Spin wait.
*/
}
}
}
return (ISC_R_SUCCESS);
}