.TITLE	NETSPA	Specify user AST routine
	.IDENT	"X1.1"
	.ENABL	LC
	.NLIST	BEX,CND,TOC
;+
; Index		Specify user AST routine
;
; Usage
;	int	lun;		/* Network data mailbox LUN */
;	int	efn;		/* Event flag # for wait */
;	int	status[2];	/* Status block */
;	{typ}	cmpast();	/* Completion AST svc. routine */
;	{typ}	usrast();	/* Net data arrival AST routn. */
;	int	dir_stat;	/* Directive status ($DSW) */
;
;	dir_stat = netspa(lun, efn, status, cmpast, usrast);
;
; Description
;
;	netspa() may be called by either the client or server task to
;	specify a user-written AST service routine to be executed
;	whenever network data arrives in the network data queue
;	mailbox.  A better name for this routine might be "Specify
;	Mailbox Arrival AST".
;
;	If there are items already in the mailbox when this function is
;	called, they do not cause an AST delivery, rather, the second
;	word of the "status" block contains the number of items in the
;	mailbox at the time of the call when the function returns.
;
;	If it is desired to process all incoming network data messages
;	at AST state, use the "completion AST" to process existing data
;	and the "user AST" to handle messages arriving after the call
;	to netspa().  For an example of this and other information,
;	see the RSX DECnet Programmer's Reference Manual (May, 1982)
;	section 2.8.13.
;
;	The function returns $DSW.
;
; Notes
;
;	The CX library's AST handling mechanism and functions must
;	be used for AST service routines (unless you have some other
;	special mechanism set up).  Most notable is the fact that
;	the normal C register save and restore routines do not
;	preserve R0 or R1, making it impossible to use them for
;	AST service.
;
;	The "user AST" places no trap-dependent parameters on the
;	stack, but the "completion AST" does (the usual I/O
;	completion flavor). Watch out!
;
;-
;
; Edits:
;
; X1.0	27-Feb-83 RBD	Initial edit
; X1.1	31-Jan-02 BQT	Changed for I/D space.
;
	.psect	c$code,i,ro
	.mcall	spa$s

NETSPA::
	mov	sp,r0		; r0 --> parameter list
	spa$s	2(r0),4(r0),6(r0),10(r0),12(r0)
	mov	$dsw,r0		; Return $DSW
	return
	.end