racket/src/racket/gc2/weak.c
2010-11-05 15:54:47 -06:00

318 lines
6.8 KiB
C

/*
Provides:
GC_malloc_weak_array
size_weak_array, mark_weak_array, fixup_weak_array
init_weak_arrays zero_weak_arrays
GC_malloc_weak_box
size_weak_box, mark_weak_box, fixup_weak_box
init_weak_boxes zero_weak_boxes
GC_malloc_ephemeron
size_ephemeron, mark_ephemeron, fixup_ephemeron
BTC_ephemeron_mark [ifdef NEW_BTC_ACCOUNT]
init_ephemerons mark_ready_ephemerons zero_remaining_ephemerons
num_last_seen_ephemerons
Requires:
weak_array_tag
weak_box_tag
ephemeron_tag
is_marked(p)
Type_Tag
*/
/******************************************************************************/
/* weak arrays */
/******************************************************************************/
static int size_weak_array(void *p, struct NewGC *gc)
{
GC_Weak_Array *a = (GC_Weak_Array *)p;
return gcBYTES_TO_WORDS(sizeof(GC_Weak_Array)
+ ((a->count - 1) * sizeof(void *)));
}
static int mark_weak_array(void *p, struct NewGC *gc)
{
GC_Weak_Array *a = (GC_Weak_Array *)p;
gcMARK2(a->replace_val, gc);
a->next = gc->weak_arrays;
gc->weak_arrays = a;
#if CHECKS
/* For now, weak arrays only used for symbols, keywords, and falses: */
{
void **data;
int i;
data = a->data;
for (i = a->count; i--; ) {
if (data[i]
&& (*(short *)(data[i]) != 48)
&& (*(short *)(data[i]) != 49)
&& (*(short *)(data[i]) != 58)) {
CRASH(1);
}
}
}
#endif
return gcBYTES_TO_WORDS(sizeof(GC_Weak_Array)
+ ((a->count - 1) * sizeof(void *)));
}
static int fixup_weak_array(void *p, struct NewGC *gc)
{
GC_Weak_Array *a = (GC_Weak_Array *)p;
int i;
void **data;
gcFIXUP2(a->replace_val, gc);
data = a->data;
for (i = a->count; i--; ) {
if (data[i])
gcFIXUP2(data[i], gc);
}
return gcBYTES_TO_WORDS(sizeof(GC_Weak_Array)
+ ((a->count - 1) * sizeof(void *)));
}
void *GC_malloc_weak_array(size_t size_in_bytes, void *replace_val)
{
GCTYPE *gc = GC_get_GC();
GC_Weak_Array *w;
/* Allcation might trigger GC, so we use park: */
gc->park[0] = replace_val;
w = (GC_Weak_Array *)GC_malloc_one_tagged(size_in_bytes
+ sizeof(GC_Weak_Array)
- sizeof(void *));
replace_val = gc->park[0];
gc->park[0] = NULL;
w->type = gc->weak_array_tag;
w->replace_val = replace_val;
w->count = (size_in_bytes >> LOG_WORD_SIZE);
return w;
}
static void init_weak_arrays(GCTYPE *gc) {
gc->weak_arrays = NULL;
}
static void zero_weak_arrays(GCTYPE *gc)
{
GC_Weak_Array *wa;
int i;
wa = gc->weak_arrays;
while (wa) {
void **data;
data = wa->data;
for (i = wa->count; i--; ) {
void *p = data[i];
if (p && !is_marked(gc, p))
data[i] = wa->replace_val;
}
wa = wa->next;
}
}
/******************************************************************************/
/* weak boxes */
/******************************************************************************/
static int size_weak_box(void *p, struct NewGC *gc)
{
return gcBYTES_TO_WORDS(sizeof(GC_Weak_Box));
}
static int mark_weak_box(void *p, struct NewGC *gc)
{
GC_Weak_Box *wb = (GC_Weak_Box *)p;
gcMARK2(wb->secondary_erase, gc);
if (wb->val) {
wb->next = gc->weak_boxes;
gc->weak_boxes = wb;
}
return gcBYTES_TO_WORDS(sizeof(GC_Weak_Box));
}
static int fixup_weak_box(void *p, struct NewGC *gc)
{
GC_Weak_Box *wb = (GC_Weak_Box *)p;
gcFIXUP2(wb->secondary_erase, gc);
gcFIXUP2(wb->val, gc);
return gcBYTES_TO_WORDS(sizeof(GC_Weak_Box));
}
void *GC_malloc_weak_box(void *p, void **secondary, int soffset)
{
GCTYPE *gc = GC_get_GC();
GC_Weak_Box *w;
/* Allcation might trigger GC, so we use park: */
gc->park[0] = p;
gc->park[1] = secondary;
w = (GC_Weak_Box *)GC_malloc_one_tagged(sizeof(GC_Weak_Box));
p = gc->park[0];
secondary = (void **)gc->park[1];
gc->park[0] = NULL;
gc->park[1] = NULL;
w->type = gc->weak_box_tag;
w->val = p;
w->secondary_erase = secondary;
w->soffset = soffset;
return w;
}
static void init_weak_boxes(GCTYPE *gc) {
gc->weak_boxes = NULL;
}
static void zero_weak_boxes(GCTYPE *gc)
{
GC_Weak_Box *wb;
wb = gc->weak_boxes;
while (wb) {
if (!is_marked(gc, wb->val)) {
wb->val = NULL;
if (wb->secondary_erase) {
void **p;
p = (void **)GC_resolve(wb->secondary_erase);
*(p + wb->soffset) = NULL;
wb->secondary_erase = NULL;
}
}
wb = wb->next;
}
}
/******************************************************************************/
/* ephemeron */
/******************************************************************************/
static int size_ephemeron(void *p, struct NewGC *gc)
{
return gcBYTES_TO_WORDS(sizeof(GC_Ephemeron));
}
static int mark_ephemeron(void *p, struct NewGC *gc)
{
GC_Ephemeron *eph = (GC_Ephemeron *)p;
if (eph->val) {
eph->next = gc->ephemerons;
gc->ephemerons = eph;
}
return gcBYTES_TO_WORDS(sizeof(GC_Ephemeron));
}
#ifdef NEWGC_BTC_ACCOUNT
static int BTC_ephemeron_mark(void *p, struct NewGC *gc)
{
if (gc->doing_memory_accounting) {
GC_Ephemeron *eph = (GC_Ephemeron *)p;
gcMARK2(eph->key, gc);
gcMARK2(eph->val, gc);
return gcBYTES_TO_WORDS(sizeof(GC_Ephemeron));
}
return mark_ephemeron(p, gc);
}
#endif
static int fixup_ephemeron(void *p, struct NewGC *gc)
{
GC_Ephemeron *eph = (GC_Ephemeron *)p;
gcFIXUP2(eph->key, gc);
gcFIXUP2(eph->val, gc);
return gcBYTES_TO_WORDS(sizeof(GC_Ephemeron));
}
void *GC_malloc_ephemeron(void *k, void *v)
{
GCTYPE *gc = GC_get_GC();
GC_Ephemeron *eph;
/* Allcation might trigger GC, so we use park: */
gc->park[0] = k;
gc->park[1] = v;
eph = (GC_Ephemeron *)GC_malloc_one_tagged(sizeof(GC_Ephemeron));
k = gc->park[0];
v = gc->park[1];
gc->park[0] = NULL;
gc->park[1] = NULL;
eph->type = gc->ephemeron_tag;
eph->key = k;
eph->val = v;
return eph;
}
void init_ephemerons(GCTYPE *gc) {
gc->ephemerons = NULL;
gc->num_last_seen_ephemerons = 0;
}
static int mark_ready_ephemerons(GCTYPE *gc)
{
GC_Ephemeron *waiting = NULL, *next, *eph;
int did_one = 0;
for (eph = gc->ephemerons; eph; eph = next) {
next = eph->next;
if (is_marked(gc, eph->key)) {
gcMARK2(eph->val, gc);
gc->num_last_seen_ephemerons++;
did_one = 1;
} else {
eph->next = waiting;
waiting = eph;
}
}
gc->ephemerons = waiting;
return did_one;
}
static void zero_remaining_ephemerons(GCTYPE *gc)
{
GC_Ephemeron *eph;
/* After unordered finalization, any remaining ephemerons
should be zeroed. */
for (eph = gc->ephemerons; eph; eph = eph->next) {
eph->key = NULL;
eph->val = NULL;
}
}