#
/* in_wait.c */

/* EMACS_MODES: c !fill */


/* Internet protocol layer for the MIT network system.  The following
 * routines are included:
 *	in_wait		Wait for an internet packet to arrive or a
 *			timeout to occur
 *
 * Note that use of this package requires the use of the standard I/O
 * library.
 */


#include	<err.h>
#include	<stdio.h>
#include	<ioctl.h>
#include	<ip.h>
#include	<netdefs.h>


in_wait (timeout)

/* Wait up to timeout seconds for an internet packet to arrive on
 * one of our presently open internet connections.  If a packet is
 * presently available the routine will return immediately.  Returns
 * TRUE if a packet is available, and FALSE if a timeout has occurred.
 *
 * Arguments:
 */

register int	timeout;		/* time to wait before returning */
{
	long	now;			/* current time */
	long	donetime;		/* timeout time */
	register int	retval;		/* return value */
	
	time (&now);
	donetime = now + timeout;
	if (!(retval = tst_and_clr (&net_avail))) {
		sysleep ((int)(donetime - now));
		retval = tst_and_clr (&net_avail);
	}
	return (retval);
}