--- Net2/sys/callout.h	2018/04/24 18:03:58	1.1.1.1
+++ Net2/sys/callout.h	2018/04/24 18:16:51	1.1.1.2
@@ -30,13 +30,19 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	@(#)callout.h	7.2 (Berkeley) 2/15/91
+ *	from: @(#)callout.h	7.2 (Berkeley) 2/15/91
+ *	callout.h,v 1.4 1993/06/27 05:59:00 andrew Exp
  */
 
+#ifndef _SYS_CALLOUT_H_
+#define _SYS_CALLOUT_H_
+
+typedef void    (*callout_t)       __P((caddr_t arg));
+
 struct callout {
 	struct callout *c_next;		/* next callout in queue */
 	caddr_t c_arg;			/* function argument */
-	int (*c_func)();		/* function to call */
+	callout_t c_func;		/* function to call */
 	int c_time;			/* ticks to the event */
 };
 
@@ -44,3 +50,5 @@ struct callout {
 struct callout *callfree, *callout, calltodo;
 int ncallout;
 #endif
+
+#endif /* !_SYS_CALLOUT_H_ */