.TITLE CNCT
	.IDENT /08MY89/

;  An external procedure to provide parent-offspring connect services to
;  Pascal-3 programs.  The exit AST is not available to Pascal.
;
; File: [22,310]CNCT.MAC
; HISTORY: 
;
;    08-May-89.  Philip Hannay.  Created from SPAWN.MAC.
;
; Last Edit: 8-MAY-1989 17:41:47 
; 
;
;  PROCEDURE CNCT(Task:Rad56; EFN:Event_Flag; VAR Status:SPAWN_Status_array);
;
;{*USER*
;CNCT will let the calling task connect to another active task for purposes
;of exit notification.  The program using the CNCT directive (caller) will
;become the "parent" task, and the program named in TASK parameter will
;become the "offspring" task.  When the offspring task exits, the parent will
;be notified by the setting of the event flag specified by the EFN parameter
;and the exit status information will be placed in the STATUS parameter.
;The type SPAWN_STATUS_ARRAY is defined in PAS$EXT:SPAWN.TYP.
;
;Note that the offspring task may exit at any time, so the STATUS parameter
;must be available to the executive.  Normally this means that STATUS
;must be a global variable.  It can also be a local variable, if you
;will not leave that procedure before the offspring task exits.
;
;If the parent task exits before the offspring task, the connection block
;will be removed from pool with no effect on the system.  Once a connection
;is made, the parent may not remove the connection except by exiting, or
;by passing all current connections to another task using the RPOI 
;directive.
;
;There is no restriction on the number of connections that can be
;made, including the number made to the same task.  For this reason, it
;is important not to indiscrimately make connections to the same task,
;as multiple connections to the same task will increase pool 
;consumption.  Use the directive status to determine if a connection
;has been made.  A connection is made ONLY if a success IS.SUC (1)
;is returned in $DSW.   The only "normal" error codes  are IE.INS or IE.ACT.
;All other errors indicate a programming error or a congested/crashing system.
;
;*STATUS CODES*
;
;   1 = successful completion (IS.SUC)
;  -1 = insufficient pool for connection block (IE.UPN)
;  -2 = specified task was a CLI or not installed (IE.INS)
;  -7 = specified task was not active (IE.ACT)
; -97 = invalid event flag specified (IE.IEF)
; -98 = DPB not in user's program space (IE.ADP)
; -99 - DIC/DPB size is invalid (IE.SDP)
;
; }
;

  	PROC CNCT
	PARAM TASK, 2*INTEGER	; RAD-50 TASK NAME
	PARAM EFN, INTEGER	; event flag
	PARAM STAT, ADDRESS	; STATUS ARRAY POINTER
	SAVE <R0, R1, R2>
	BEGIN

	.MCALL CNCT$S
	MOV SP,R0	;PRESERVE STACK REFERENCE
	MOV SP, R1	;GET POINTER TO TASK NAME
	ADD #TASK, R1	; R1 -> TASK NAME
	CLR R2
  	MOVB EFN(SP), R2 ; GET BYTE ONLY
	CNCT$S R1,R2,,STAT(0)
	ENDPR

	.END