external/bsd/bind/dist/lib/isc/win32/once.c

   1 /*      $NetBSD$        */
   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 }