CORAL.MAC;2/AU/-BF=CORAL.MAC;1
\
-2,2,/;BENCH/
	.IDENT	/BENCH/
-11,11,/;BENCH/
;
; CORE BUFFER ALLOCATION ROUTINES
;
; BENCHMARKING VERSION
-20,34,/;BENCH/
; *******  THIS VERSION IS NOT INTENDED FOR PERMANENT INSTALLATION
; *******  IN THE OPERATING SYSTEM....IT IS INTENDED FOR BENCHMARKING
; *******  PURPOSES ONLY!  BUYER BEWARE!
;
;	DANIEL STEINBERG
;	SRI INTERNATIONAL
;	(415) 326-6200  EXT.5539
;
; THE ROUTINES AT $ALOCB AND $DEACB HAVE BEEN MODIFIED SO THAT THE BIT
; OFFSETS IN THE WORD AT  $AFLG$  (DEFINED GLOBALLY) HAVE THE FOLLOWING
; IMPLICATIONS:
;
; BIT	MEANING
;
;  AB	IF SET, BIT 0 OF LOCATION  $AMRK$  IS TURNED ON WHENEVER $ALOCB
;	IS CALLED.  THE BIT IS TURNED OFF WHEN A 'RETURN' IS EXECUTED.
;
;  A1	IF SET, BIT 0 OF  $AMRK$  IS TURNED ON WHENEVER $ALOC1 IS CALLED.
;
; AE0	IF SET, BIT 0 OF  $AMRK$  IS LEFT ON WHEN ON ALLOCATION FAILURE.
;
; AE1	IF SET, BIT 1 OF  $AMRK$  IS TURNED ON AT ALLOCATION FAILURE.
;
; ABK 	IF SET, LARGE CHUNKS OF POOL ARE USED BY ALLOCATING FROM THE
;	BACK END OF THE CHUNK...IF CLEAR, ALLOCATE FROM FRONT
;
; ARV 	IF SET, USE ROVING ALLOCATION ALGORITHM
;	IF CLEAR, USE THE OLD STANDARD FIRST FIT
;
; APV IF SET, (AND ARV) ROVING ALLOCATION SEARCH STARTS AT PREVIOUSLY
;	 FRAGMENTED CHUNK......IF CLEAR, START AT NEXT CHUNK
;
%
-42,42,/;BENCH/
-47,49,/;BENCH/
\
; THIS ROUTINE IS CALLED TO ALLOCATE AN EXEC CORE BUFFER. THE ORIGINAL
; ALGORITHM IS FIRST FIT AND BLOCKS ARE ALLOCATED IN MULTIPLES OF FOUR
; BYTES. THE NEW ALGORITHM (SELECTED IF BIT 'ARV' OF $AFLG$ IS SET) USES
; A ROVING ALLOCATION POINTER ($ROVER) WHICH SPECIFIES THE FIRST FREE
; CHUNK TO START THE ALLOCATION SEARCH (A LA KNUTH).  $ROVER IS UPDATED
; EITHER TO START THE NEXT SEARCH AT THE BLOCK FOLLOWING THE LAST
; ALLOCATION (KNUTH'S WAY), OR AT THE BLOCK MOST RECENTLY ALLOCATED
; FROM (GENERALLY CAUSING FAST ALLOCATIONS).
;
; *** NOTE THAT $DEAC1 *MUST* BE MODIFIED IF $ROVER IS USED ***
;     *** SEE THE NOTE UNDER $DEACB DOCUMENTATION BELOW ***
%
-64,69,/;BENCH/
$AMRK$==167774	;*** DR11-K OUTPUT REGISTER ADDRESS ***
		;THE 1ST BIT OF THE DR11-K OUTPUT REG WILL BE MONITORED
		;TO COLLECT DATA ON ALLOCATION TIME, FREQUENCY, ETC.

; $AFLG$ BIT OFFSETS:
AB=1
A1=2
AE0=4
AE1=10
ABK=20
ARV=40
APV=100
	;***  TO SPECIFY PARTICULAR STARTUP CONDITIONS, YOU MAY WANT TO
	;     ENTER A GLBPAT IN THE TASK BUILD COMMAND FILE FOR $AFLG$
	;***  IF $AFLG$ IS ZERO, THE ORIGINAL RSX V3.2 ALGORITHM WILL
	;     BE IN USE AT THE INITIAL SYSTEM BOOT.

	.IIF DF,DS$ROV	.ERROR	;MULTIPLE DEFINITION OF $ROVER IN SYSCM
$AFLG$::	.WORD	0		;BENCHMARKING FLAG WORD
$ROVER::	.WORD	0		;ROVING ALLOCATION POINTER
	.ENABL	LSB
$ALOCB::
	BIT	#AB,$AFLG$	;FLAG $ALOCB ENTRY?
	BEQ	500$		; NO
	BIS	#1,@#$AMRK$	; YES...SET BIT 0
500$:
	MOV	#$CRAVL-2,R0	;POINT TO ALLOCATION MASK WORD

	.IF	DF,Q$$OPT
-80,120,/;BENCH/
	BIC	#3,@#$AMRK$	; CLEAR ALLOCATION ERROR BITS
	RETURN			;
4$:	MOV	#$CRAVL-2,R0	;POINT BACK TO ALLOCATION MASK WORD
	.ENDC	;DF,Q$$OPT

$ALOC1::ADD	(R0),R1		;ROUND TO NEXT BOUNDARY
	BIC	(R0)+,R1	;CLEAR EXCESS
5$:	SEC			;ASSUME ZERO LENGTH REQUEST
	BEQ	ARET		;IF EQ, ZERO LENGTH REQUEST
	BIT	#A1,$AFLG$	;FLAG $ALOC1 ENTRY?
	BEQ	505$		; NO
	BIS	#1,@#$AMRK$	; YES...SET BIT 0
505$:
	.IF DF,R$$DER
	MOV	R0,-(SP)	;SAVE ADDRESS OF LISTHEAD
	.ENDC	;DF,R$$DER

	BIT	#ARV,$AFLG$	;NEW ALLOCATION?
	BEQ	OLDAL1		; NO...USE OLD ROUTINE
NEWAL1:
	CMP	R0,#$CRAVL	;ALLOCATING FROM EXEC POOL?
	BNE	120$		; NO....DON'T USE $ROVER
	MOV	$ROVER,R0	; YES...GET PREVIOUSLY UPDATED PTR
	BEQ	105$		;IF ZERO, START AT LISTHEAD
	CALL	ALLOC		;CHECK POOL FROM $ROVER TO END
	BCC	508$		; SUCCESS
105$:	MOV	#$CRAVL,R0	;EITHER LAST SEARCH FAILED OR $ROVER=0
	CALL	ALLOC		;TRY FROM TOP OF EXEC POOL TO END
	BCS	115$		; FAILURE
508$:	MOV	R2,$ROVER	;SAVE PREVIOUS PTR
	BIT	#APV,$AFLG$	;IS THAT RIGHT?
	BNE	510$		; YES
	MOV	(R2),$ROVER	; NO...SAVE NEXT BLOCK ADDRESS
510$:
AOUT:
	.IF DF,R$$DER
	INC	(SP)+		;CLEAN STACK W/O AFFECTING C-BIT
	.ENDC	;DF,R$$DER

	BCC	520$		;SUCCESSFUL ALLOCATION
	BIT	#AE1,$AFLG$	; FAILURE...SET BIT 1?
	BEQ	515$		; NO
	BIS	#2,@#$AMRK$	; YES
515$:	BIT	#AE0,$AFLG$	; FAILURE...LEAVE BIT 0 SET?
	BEQ	ARET		; NO
	RETURN			; YES
520$:	BIC	#3,@#$AMRK$	;SUCCESS...CLEAR ERROR BITS
ARET:	BIC	#1,@#$AMRK$	; CLEAR ONLY BIT 0
	RETURN

115$:	MOV	#0,$ROVER	;ALLOCATION FAILURE, LEAVE C-SET
	BR	AOUT		;CLEAN UP AND EXIT

120$:	CALL	ALLOC		;SEARCH LINKED LIST (NOT EXEC POOL)
	BR	AOUT		;CLEAN UP AND EXIT

OLDAL1:	CALL	ALLOC		;USE RSX V3.2 ALLOCATION ALGORITHM
	BR	AOUT		;MERGE WITH BIT CHECKS




ALLOC:	SEC			;ASSUME FAILURE (HOW OPTIMISTIC!)
10$:	MOV	R0,R2		;SAVE ADDRESS OF CURRENT BLOCK
	MOV	(R2),R0		;GET ADDRESS OF NEXT BLOCK
	BEQ	35$		;IF EQ END OF CHAIN

	.IF DF,R$$DER
	CMP	R0,R2		;BACKWARD REFERENCE?
	BLO	40$		;IF LE YES
	CMP	#$CRAVL,2(SP)	;ALLOCATION IN EXEC'S POOL?
	BNE	15$		;IF NE, NO
	CMP	R0,#$POOL	;ALLOCATION BEFORE EXEC POOL?
	BLO	40$		;IF LO YES
	CMP	R0,$EXSIZ	;ALLOCATION PAST END OF POOL?
	BHI	40$		;IF HI YES
15$:				;REF LABEL
	.ENDC	;DF,R$$DER

	CMP	2(R0),R1	;BLOCK BIG ENOUGH?
	BLO	10$		;IF LO NO
	BEQ	20$		;IF EQ BLOCK IS EXACT SIZE
	BIT	#ABK,$AFLG$	;ALLOCATE FROM BACK OF CHUNK?
	BEQ	AFRONT		; NO, FROM FRONT (RSX V3.2 WAY)
ABACK:	SUB	R1,2(R0)	;CALCULATE SIZE REMAINING
	ADD	2(R0),R0	;POINT TO BLOCK TO ALLOCATE
	RETURN			;DONE

AFRONT:	TST	(R0)+		;POINT TO SIZE OF FREE BLOCK
-128,146,/;BENCH/
35$:	RETURN

	.IF DF,R$$DER
40$:	CRASH			;POOL CLOBBERED
	.ENDC	;DF,R$$DER
	.DSABL	LSB
-223,223,/;BENCH/
\
				;FALL THRU TO $DEACB
%
-232,,/;BENCH/
\
; *** NOTE: THE FOLLOWING CHANGE TO $DEACB HAS BEEN MADE:
;	IF $ROVER IS POINTING TO A BLOCK WHICH IS MERGED INTO THE
;	PREVIOUS BLOCK, $ROVER IS CLEARED SO THAT THE NEXT ALLOCATION
;	SEARCH STARTS AT THE TOP OF THE FREE LIST.
;
-242,249,/;BENCH/
;	ADDRESS AND IS AGLOMERATED IF NECESSARY WITH ADJACENT BLOCKS.
;-
$DEACB::MOV	#$CRAVL-2,R3	;POINT TO ALLOCATION MASK WORD

	.IF	DF,Q$$OPT
-262,264,/;BENCH/
	.ENDC	;DF,Q$$OPT
-270,276,/;BENCH/
	.IF DF,R$$DER
	MOV	R3,-(SP)	;SAVE ADDRESS OF LISTHEAD
	.ENDC	;DF,R$$DER
-287,288,/;BENCH/
	.IF DF,R$$DER
-297,308,/;BENCH/
%
	.ENDC	;DF,R$$DER

	CMP	R3,(SP)+	;EQUAL TO NEXT IN CHAIN?

	.IF DF,R$$DER
	BLO	90$		;IF LO, DEALLOCATION OVERLAPS
	.ENDC	;DF,R$$DER

	BNE	60$		;IF NE NO
	CMP	R3,$ROVER	;ABOUT TO MERGE AWAY ROVER BLOCK?
	BNE	202$		; NO...OK
	CLR	$ROVER		; YES..START NEXT SEARCH AT $CRAVL
202$:				;REFERENCE LABEL
\
-316,317,/;BENCH/
	.IF DF,R$$DER
-322,323,/;BENCH/
	.ENDC	;DF,R$$DER
-331,346,/;BENCH/
	.IF DF,R$$DER
	TST	(SP)+		;POP ADDRESS OF LISTHEAD
	.ENDC	;DF,R$$DER

80$:	RETURN			;

	.IF DF,R$$DER
90$:	TST	R3		;INSERT AT END OF LIST?
	BEQ	60$		;IF EQ YES, OK
100$:	CRASH			;CRASH SYSTEM, BAD CORE DEALLOCATION
	.ENDC	;DF,R$$DER
/