/*
* Is the block starting at h of size len bytes black listed? If so,
* return the address of the next plausible r such that (r, len) might not
* be black listed. (R may not actually be in the heap. We guarantee only
* that every smaller value of r after h is also black listed.)
* If (h,len) is not black listed, return 0.
* Knows about the structure of the black list hash tables.
*/
struct hblk * GC_is_black_listed(struct hblk *h, word len)
{
word index = PHT_HASH((word)h);
word i;
word nblocks;
if (!GC_all_interior_pointers
&& (get_pht_entry_from_index(GC_old_normal_bl, index)
|| get_pht_entry_from_index(GC_incomplete_normal_bl, index))) {
return (h+1);
}
nblocks = divHBLKSZ(len);
for (i = 0;;) {
if (GC_old_stack_bl[divWORDSZ(index)] == 0
&& GC_incomplete_stack_bl[divWORDSZ(index)] == 0) {
/* An easy case */
i += WORDSZ - modWORDSZ(index);
} else {
if (get_pht_entry_from_index(GC_old_stack_bl, index)
|| get_pht_entry_from_index(GC_incomplete_stack_bl, index)) {
return(h+i+1);
}
i++;
}
if (i >= nblocks) break;
index = PHT_HASH((word)(h+i));
}
return(0);
}
/* Return the total number of (stack) black-listed bytes. */
static word total_stack_black_listed(void)
{
unsigned i;
word total = 0;
for (i = 0; i < GC_n_heap_sects; i++) {
struct hblk * start = (struct hblk *) GC_heap_sects[i].hs_start;
struct hblk * endp1 = start + divHBLKSZ(GC_heap_sects[i].hs_bytes);
total += GC_number_stack_black_listed(start, endp1);
}
return(total * HBLKSIZE);
}
/* debugging intolerably slow.) */
GC_API void * GC_CALL GC_same_obj(void *p, void *q)
{
struct hblk *h;
hdr *hhdr;
ptr_t base, limit;
word sz;
if (!GC_is_initialized) GC_init();
hhdr = HDR((word)p);
if (hhdr == 0) {
if (divHBLKSZ((word)p) != divHBLKSZ((word)q)
&& HDR((word)q) != 0) {
goto fail;
}
return(p);
}
/* If it's a pointer to the middle of a large object, move it */
/* to the beginning. */
if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
h = HBLKPTR(p) - (word)hhdr;
hhdr = HDR(h);
while (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
h = FORWARDED_ADDR(h, hhdr);
hhdr = HDR(h);
}
limit = (ptr_t)h + hhdr -> hb_sz;
if ((ptr_t)p >= limit || (ptr_t)q >= limit || (ptr_t)q < (ptr_t)h ) {
goto fail;
}
return(p);
}
sz = hhdr -> hb_sz;
if (sz > MAXOBJBYTES) {
base = (ptr_t)HBLKPTR(p);
limit = base + sz;
if ((ptr_t)p >= limit) {
goto fail;
}
} else {
size_t offset;
size_t pdispl = HBLKDISPL(p);
offset = pdispl % sz;
if (HBLKPTR(p) != HBLKPTR(q)) goto fail;
/* W/o this check, we might miss an error if */
/* q points to the first object on a page, and */
/* points just before the page. */
base = (ptr_t)p - offset;
limit = base + sz;
}
/* [base, limit) delimits the object containing p, if any. */
/* If p is not inside a valid object, then either q is */
/* also outside any valid object, or it is outside */
/* [base, limit). */
if ((ptr_t)q >= limit || (ptr_t)q < base) {
goto fail;
}
return(p);
fail:
(*GC_same_obj_print_proc)((ptr_t)p, (ptr_t)q);
return(p);
}
