void ThreadLocalCollector::scan_with_layout(const Range &range, const unsigned char* map) {
// convert to double indirect
void **reference = (void **)range.address();
void ** const end = (void **)range.end();
Range subrange;
// while not '\0' terminator
while (unsigned data = *map++) {
// extract the skip and run
unsigned skip = data >> 4;
unsigned run = data & 0xf;
// advance the reference by the skip
reference += skip;
// scan runs as a range.
subrange.set_range(reference, reference + run);
if (subrange.address() < end && subrange.end() <= end) {
// <rdar://problem/6516045>: make sure we only scan valid ranges.
scan_range(subrange);
} else {
break;
}
reference += run;
}
if (reference < end) {
// since objects can be allocated with extra data at end, scan the remainder conservatively.
subrange.set_range((void *)reference, end);
scan_range(subrange);
}
}
void ThreadLocalCollector::scan_range(const Range &range) {
// set up the iteration for this range
void ** reference = (void **)range.address();
void ** const end = (void **)range.end();
// local copies of valid address info
const uintptr_t valid_lowest = (uintptr_t)_coverage.address();
const uintptr_t valid_size = (uintptr_t)_coverage.end() - valid_lowest;
// iterate through all the potential references
for (void *last_valid_pointer = end - 1; reference <= last_valid_pointer; ++reference) {
// get referent
void *referent = *reference;
// if is a block then check this block out
if (((intptr_t)referent - valid_lowest) < valid_size) {
mark_push_block(referent);
}
}
}