(FILECREATED "10-Sep-84 22:48:44" {ERIS}<LISP>CAROL>PATCHES>BIGREFCNTPATCH.;1
 2568   

      changes to:  (VARS BIGREFCNTPATCHCOMS))


(* Copyright (c) 1984 by Xerox Corporation. All rights reserved.)

(PRETTYCOMPRINT BIGREFCNTPATCHCOMS)

(RPAQQ BIGREFCNTPATCHCOMS
 ((FNS \GC.MODIFY.BIGREFCNT)))
(DEFINEQ

(\GC.MODIFY.BIGREFCNT

  (LAMBDA (ENTRY CASE PTR)                                   (* JonL "10-Sep-84 22:38")


          (* Called from .MODENTRY. to do one of the 4 reference counting cases on PTR. ENTRY is the gc table entry whose 

	  CNT field is \MAXHTCNT)



    (PROG ((OVENTRY \HTBIGCOUNT)
	   TMP CNT)
          (COND
	    ((ODDP (\LOLOC PTR))                             (* This should be an error, but accomodate it for now)

	      (SETQ PTR (\ADDBASE PTR -1))))
      LP  (COND
	    ((NEQ (SETQ TMP (fetch
 OVFLPTR of
 OVENTRY))
		  PTR)
	      (COND
		((NULL TMP)
		  (\GC.BIGREFCNT.MISSING PTR)
		  (RETURN)))
	      (SETQ OVENTRY (\ADDBASE OVENTRY \HTBIGENTRYSIZE))
	      (GO LP)))
          (SELECTC CASE
		   (\ADDREFCASE (replace
 OVFLCNTLO of
 OVENTRY
				   with
 (COND
					  ((ILESSP (SETQ TMP (fetch
 OVFLCNTLO of
 OVENTRY))
						   MAX.SMALLP)
					    (ADD1 TMP))
					  (T (add
 (fetch
 OVFLCNTHI of
 OVENTRY)
						  1)
					     0))))
		   (\DELREFCASE (replace
 OVFLCNTLO of
 OVENTRY
				   with
 (COND
					  ((IGEQ (SETQ TMP (SUB1 (fetch
 OVFLCNTLO of
 OVENTRY)))
						 \MAXHTCNT)
					    TMP)
					  ((EQ 0 (fetch
 OVFLCNTHI of
 OVENTRY))
                                                             (* Ref cnt has fallen below max, bring it out)

					    (replace
 (GC CNT) of
 ENTRY with
 TMP)
					    (replace
 OVFLPTR of
 OVENTRY with
 T)
                                                             (* mark deleted)

					    TMP)
					  ((ILESSP TMP 0)
					    (add
 (fetch
 OVFLCNTHI of
 OVENTRY)
						 -1)
					    MAX.SMALLP)
					  (T TMP))))
		   (\SCANREFCASE (replace
 (GC STKBIT) of
 ENTRY with
 T))
		   (\UNSCANREFCASE (replace
 (GC STKBIT) of
 ENTRY with
 NIL))
		   NIL)                                      (* Must worry about SCANREF cases since the main entry 

							     is inspected by others, regardless of the refcnt)

                                                             (* Value is NIL to tell .MODENTRY.

							     that cnt ~= 1)

          (RETURN NIL))))
)
(PUTPROPS BIGREFCNTPATCH COPYRIGHT ("Xerox Corporation" 1984))
(DECLARE: DONTCOPY
  (FILEMAP (NIL (303 2483 (\GC.MODIFY.BIGREFCNT 313 . 2481)))))
STOP