Made API for garbage collector (now called heap system)

This commit is contained in:
Martin Haye 2015-08-18 09:39:05 -07:00
parent a6c2b46a92
commit 39c37c2517
2 changed files with 97 additions and 29 deletions

View File

@ -50,10 +50,6 @@ gcHash_link = $5300
gcHash_dstLo = $5400
gcHash_dstHi = $5500
; Heap area
heapStart = $F000 ; must be page aligned
heapEnd = $F800 ; must be page aligned
; Other equates
prodosMemMap = $BF58
@ -651,6 +647,8 @@ typeTblL !fill MAX_TYPES
typeTblH !fill MAX_TYPES
typeLen !fill MAX_TYPES ; length does not include type byte
heapStartPg !byte 0
heapEndPg !byte 0
heapTop !word 0
gcHash_top !byte 0
nHeapBlks !byte 0
@ -682,12 +680,11 @@ setTypeTbl: !zone
; Clear the heap
heapReset: !zone
lda #<heapStart
sta heapTop
lda #>heapStart
sta heapTop
lda #0
sta heapTop
sta nHeapBlks
lda heapStartPg
sta heapTop
; fall through to:
; Zero memory heapTop.heapEnd
heapClr: !zone
@ -699,7 +696,7 @@ heapClr: !zone
inx
bne .st
iny
cpy #>heapEnd
cpy heapEndPg
bne .pg
rts
@ -722,7 +719,7 @@ heapAlloc: !zone
adc pTmp
bcc +
iny
cpy #>heapEnd
cpy heapEndPg
bcs .needgc
+ sta heapTop
sty heapTop+1
@ -790,7 +787,7 @@ heapCheck: !zone
bcc .blklup
inc pTmp+1
lda pTmp+1
cmp #>heapEnd
cmp heapEndPg
bcc .blklup
bcs heapCorrupt
.isobj and #$7F
@ -814,9 +811,9 @@ heapCheck: !zone
bcs heapCorrupt ; but beyond end is not ok
+ lda (pTmp),y ; get hi byte of ptr
beq .tscan ; null is ok
cmp #>heapStart ; else check if < start of heap
cmp heapStartPg ; else check if < start of heap
bcc heapCorrupt
cmp #>heapEnd ; or >= than end of heap
cmp heapEndPg ; or >= than end of heap
bcc .tscan
heapCorrupt:
ldx pTmp
@ -832,9 +829,8 @@ gc1_mark: !zone
- sta gcHash_first,x
inx
bne -
lda #<heapStart ; global block is at very start of heap
sta pSrc
lda #>heapEnd
stx pSrc ; X is zero'd from loop above
lda heapStartPg
sta pSrc+1
sec ; sec means add if not found
jsr gcHash_chk ; seed the hash, and thus our queue, with the global block
@ -897,10 +893,10 @@ gc3_fix:
; Phase 2 of Garbage Collection: sweep all accessible blocks together
gc2_sweep: !zone
lda #<heapStart
lda #0
sta pSrc
sta pDst
lda #>heapStart
lda heapStartPg
sta pSrc+1
sta pDst+1
.outer clc ; clc = do not add to hash

View File

@ -248,19 +248,13 @@ DEBUG_MEM = $1A
; Print out the currently allocated memory blocks and their states.
;------------------------------------------------------------------------------
CHAIN_LOADER = $1E
; Input: X-reg / Y-reg - pointer to loader (X=lo, Y=hi) to add to chain
CHECK_MEM = $1E
; Input: None
;
; Output: None
;
; Add a loader to the chain just after this loader. The current next
; loader (if there is one) will be passed to the new loader with another
; CHAIN_LOADER command.
;
; The purpose of a loader chain is to insert faster devices between the
; main/aux loader (fastest) and the disk loader (slowest). Note that the
; main mem and aux mem loaders are conceptually one; a chained loader will
; always be inserted after them, not between them.
; Check that memory manager structures (and heap structures, if a heap
; has been set) are all intact.
;------------------------------------------------------------------------------
FATAL_ERROR = $1F
@ -274,6 +268,84 @@ FATAL_ERROR = $1F
;
; This command halts and thus never returns.
;------------------------------------------------------------------------------
HEAP_SET = $20
; Input: X-reg(lo) / Y-reg(hi): pointer to allocated block for heap
;
; Output: None
;
; Establishes a block of memory to use as a garbage collected small-object
; heap. The block must be page-aligned and sized in whole pages, and
; generally should be locked first.
;------------------------------------------------------------------------------
HEAP_TYPE = $21
; Input: X-reg(lo) / Y-reg(hi): pointer to type table
;
; Output: None
;
; Adds a type to the list of known heap types. Each type will be assigned
; a number starting at $80 and going up to $81, $82, etc. By convention
; type $80 should be the single "Global" object from which all others live
; objects can be traced.
;
; The type table for the type should be laid out as follows:
; byte 0: length byte (1 to 127)
; byte 1: offset of first pointer (1 to 127)
; byte 2: offset of second pointer
; ...
; byte n: zero (0) value marks end of table
;------------------------------------------------------------------------------
HEAP_ALLOC = $22
; Input: X-reg: string length $01-7F, or type code $80-FF
;
; Output: X-reg(lo) / Y-reg(hi): pointer to allocated object space
;
; Allocates an object on the heap. If X <= $7F, it's a string object
; (no internal pointers). If X >= $80, it's a typed object corresponding
; to the types added with HEAP_TYPE.
;
; The first byte of the returned block will be the length or type code,
; (which you must never change), and subsequent bytes are initialized to
; all zero.
;
; By convention, the very first block allocated should be of the "Global"
; type ($80) and all other live objects must be traceable from there.
;------------------------------------------------------------------------------
HEAP_COLLECT = $23
; Input: None.
;
; Output: X-reg(lo) / Y-reg(hi): free space in heap after collection
;
; Traces objects in the heap to determine which ones are "live", that is,
; reachable from the very first object allocated. By convention, that first
; object should be of the "Global" type, i.e. $80, and everything reachable
; from pointers there is considered live.
;
; Live objects are then coalesced together in contiguous memory, squeezing
; out any objects that can no longer be reached.
;
; NOTE: The main memory area from $4000.5FFF is used during the collection
; process. Therefore, HEAP_COLLECT should not be run during a
; START_LOAD..FINISH_LOAD sequence, nor when hi-res page 2 is being shown.
;------------------------------------------------------------------------------
CHAIN_LOADER = $30
; Input: X-reg / Y-reg - pointer to loader (X=lo, Y=hi) to add to chain
;
; Output: None
;
; Add a loader to the chain just after this loader. The current next
; loader (if there is one) will be passed to the new loader with another
; CHAIN_LOADER command.
;
; The purpose of a loader chain is to insert faster devices between the
; main/aux loader (fastest) and the disk loader (slowest). Note that the
; main mem and aux mem loaders are conceptually one; a chained loader will
; always be inserted after them, not between them.
;------------------------------------------------------------------------------
; Convenience for writing assembly routines in PLASMA source
; Macro param: number of parameters passed from PLASMA to the asm routine