1 files changed, 54 insertions, 0 deletions
diff --git a/lib/isc/win32/once.c b/lib/isc/win32/once.c
new file mode 100644
index 0000000..b504776
--- /dev/null
+++ b/lib/isc/win32/once.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2004, 2007  Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (C) 1999-2001  Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC 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 1.12 2007/06/18 23:47:49 tbox Exp $ */
+
+/* Principal Authors: DCL */
+
+#include <config.h>
+
+#include <windows.h>
+
+#include <isc/once.h>
+#include <isc/assertions.h>
+#include <isc/util.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) {
+				/*
+				 * Sleep(0) indicates that this thread 
+				 * should be suspended to allow other 
+				 * waiting threads to execute.
+				 */
+				Sleep(0);
+			}
+		}
+	}
+
+	return (ISC_R_SUCCESS);
+}