bool VMMemPointerIterator::remove_uncommitted_region(MemPointerRecord* rec) {
assert(rec->is_uncommit_record(), "sanity check");
VMMemRegion* cur;
cur = (VMMemRegion*)current();
assert(cur->is_reserved_region() && cur->contains_region(rec),
"Sanity check");
// thread's native stack is always marked as "committed", ignore
// the "commit" operation for creating stack guard pages
if (FLAGS_TO_MEMORY_TYPE(cur->flags()) == mtThreadStack &&
FLAGS_TO_MEMORY_TYPE(rec->flags()) != mtThreadStack) {
return true;
}
cur = (VMMemRegion*)next();
while (cur != NULL && cur->is_committed_region()) {
// region already uncommitted, must be due to duplicated record
if (cur->addr() >= rec->addr() + rec->size()) {
break;
} else if (cur->contains_region(rec)) {
// uncommit whole region
if (cur->is_same_region(rec)) {
remove();
break;
} else if (rec->addr() == cur->addr() ||
rec->addr() + rec->size() == cur->addr() + cur->size()) {
// uncommitted from either end of current memory region.
cur->exclude_region(rec->addr(), rec->size());
break;
} else { // split the committed region and release the middle
address high_addr = cur->addr() + cur->size();
size_t sz = high_addr - rec->addr();
cur->exclude_region(rec->addr(), sz);
sz = high_addr - (rec->addr() + rec->size());
if (MemTracker::track_callsite()) {
MemPointerRecordEx tmp(rec->addr() + rec->size(), cur->flags(), sz,
((VMMemRegionEx*)cur)->pc());
return insert_record_after(&tmp);
} else {
MemPointerRecord tmp(rec->addr() + rec->size(), cur->flags(), sz);
return insert_record_after(&tmp);
}
}
}
cur = (VMMemRegion*)next();
}
// we may not find committed record due to duplicated records
return true;
}
