/************************************************************************/
/*									*/
/*	        	      L O S  A L A M O S			*/
/*		        Los Alamos National Laboratory			*/
/*		         Los Alamos, New Mexico 87545			*/
/*									*/
/*	Copyright, 1986, The Regents of the University of California.	*/
/*									*/
/*									*/
/*	History								*/
/*	-------								*/
/*	06xx89	joh	First Release					*/
/*	060591	joh	delinting					*/
/*									*/
/*_begin								*/
/************************************************************************/
/*									*/
/*	Title:	IOC network flow control module				*/
/*	File:	atcs:[ca]flow_control.c					*/
/*	Environment: VMS. UNIX, VRTX					*/
/*	Equipment: VAX, SUN, VME					*/
/*									*/
/*									*/
/*	Purpose								*/
/*	-------								*/
/*									*/
/*	ioc flow control module						*/
/*									*/
/*									*/
/*	Special comments						*/	
/*	------- --------						*/
/*									*/	
/************************************************************************/
/*_end									*/

static char	*sccsId = "@(#) $Id$";

#include		"iocinf.h"



/*
 * FLOW CONTROL
 * 
 * Keep track of how many times messages have 
 * come with out a break in between and 
 * suppress monitors if we are behind
 * (an update is sent when we catch up)
 */
void flow_control(struct ioc_in_use *piiu)
{
	unsigned        nbytes;
	int    		status;

	LOCK;

	/*
	 * use of the additional system call here does not
	 * seem to slow things down appreciably
	 */
	status = socket_ioctl(piiu->sock_chan,
			      FIONREAD,
			      &nbytes);
	if (status < 0) {
		TAG_CONN_DOWN(piiu);
		UNLOCK;
		return;
	}

	/*	
	 * I wish to avoid going into flow control however 
	 * as this impacts the performance of batched fetches
	 */
	if (nbytes) {
		piiu->contiguous_msg_count++;
		if (!piiu->client_busy)
			if (piiu->contiguous_msg_count >
			    MAX_CONTIGUOUS_MSG_COUNT) {
				piiu->client_busy = TRUE;
				ca_busy_message(piiu);
#				if defined(DEBUG) 
					printf("fc on\n");
#				endif
			}
	} else {
		piiu->contiguous_msg_count = 0;
		if (piiu->client_busy) {
#			if defined(DEBUG) 
				printf("fc off\n");
#			endif
			ca_ready_message(piiu);
			piiu->client_busy = FALSE;
		}
	}

	UNLOCK;
	return;
}