.title	rcvdat
;
;	this routine performs a receive data or stop;  if the task is stopped
;	and then unstopped, it performs a receive data to fetch the message
;	which caused it to be unstopped
;	call with the following interface
;
;	subroutine rcvdat([task], buffer)
;
	.mcall	rcst$s,rcvd$s
ap=%5
tsk=2
buf=4
	.psect	$r.rod,con,ro,rel,lcl,d
dumtsk:	.word	0,0		; dummy task name to use if user omits it
	.psect	$r.roi,con,ro,rel,lcl,i
	.enabl	lsb
rcvdat::
	mov	tsk(ap),r1	; move address of task field into r0
	cmp	#-1,r1		; see if user left it blank
	bne	10$		; if !=, then user supplied task name
	mov	#dumtsk,r1	; place null task name address into r0
10$:
	rcst$s	r1,buf(ap)	; receive data or stop
	cmp	$dsw,#is.suc	; received data?
	beq	20$		; YES
	rcvd$s	r1,buf(ap)	; get data which unstopped us
20$:
	mov	$dsw,r0		; return dsw
	return
	.end