410 |
|
scanretire() /* retire old scanlines to free list */ |
411 |
|
{ |
412 |
|
SCAN *sold[NRETIRE]; |
413 |
– |
SCAN head; |
413 |
|
int n; |
414 |
|
int h; |
415 |
|
register SCAN *sl; |
416 |
|
register int i; |
417 |
|
/* grab the NRETIRE oldest scanlines */ |
418 |
|
sold[n = 0] = NULL; |
419 |
< |
for (h = 0; h < HSIZE; h++) { |
420 |
< |
head.next = hashtab[h]; |
421 |
< |
sl = &head; |
422 |
< |
while (sl->next != NULL) { |
424 |
< |
for (i = n; i && sold[i-1]->lused > sl->next->lused; i--) |
425 |
< |
if (i == NRETIRE) { /* reallocate */ |
426 |
< |
register int oh; |
427 |
< |
oh = shash(sold[NRETIRE-1]->y); |
428 |
< |
sold[NRETIRE-1]->next = hashtab[oh]; |
429 |
< |
if (h == oh) { |
430 |
< |
head.next = sold[NRETIRE-1]; |
431 |
< |
if (sl == &head) |
432 |
< |
sl = head.next; |
433 |
< |
} else |
434 |
< |
hashtab[oh] = sold[NRETIRE-1]; |
435 |
< |
} else /* else bubble up */ |
419 |
> |
for (h = 0; h < HSIZE; h++) |
420 |
> |
for (sl = hashtab[h]; sl != NULL; sl = sl->next) { |
421 |
> |
for (i = n; i && sold[i-1]->lused > sl->lused; i--) |
422 |
> |
if (i < NRETIRE) |
423 |
|
sold[i] = sold[i-1]; |
424 |
|
if (i < NRETIRE) { |
425 |
< |
sold[i] = sl->next; |
439 |
< |
sl->next = sl->next->next; |
425 |
> |
sold[i] = sl; |
426 |
|
if (n < NRETIRE) /* grow list */ |
427 |
|
n++; |
428 |
< |
} else |
443 |
< |
sl = sl->next; |
428 |
> |
} |
429 |
|
} |
445 |
– |
hashtab[h] = head.next; |
446 |
– |
} |
430 |
|
/* put scanlines into free list */ |
431 |
< |
for (i = 1; i < n; i++) { |
432 |
< |
sold[i]->next = freelist; |
433 |
< |
freelist = sold[i]; |
431 |
> |
for (i = 0; i < n; i++) { |
432 |
> |
h = shash(sold[i]->y); |
433 |
> |
sl = hashtab[h]; |
434 |
> |
if (sl == sold[i]) |
435 |
> |
hashtab[h] = sl->next; |
436 |
> |
else { |
437 |
> |
while (sl->next != sold[i]) /* IS in list */ |
438 |
> |
sl = sl->next; |
439 |
> |
sl->next = sold[i]->next; |
440 |
> |
} |
441 |
> |
if (i > 0) { /* save oldest as return value */ |
442 |
> |
sold[i]->next = freelist; |
443 |
> |
freelist = sold[i]; |
444 |
> |
} |
445 |
|
} |
446 |
|
return(sold[0]); |
447 |
|
} |