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*/
template <class T> template <class X> ValueRecorder<T>::IndexCache<X>::IndexCache() {
assert(first_index > 0, "initial zero state of cache must be invalid index");
Copy::zero_to_bytes(&_cache[0], sizeof(_cache));
}
template <class T> int ValueRecorder<T>::size() {
_complete = true; if (_handles == NULL) return 0; return _handles->length() * sizeof(T);
}
template <class T> void ValueRecorder<T>::copy_values_to(nmethod* nm) {
assert(_complete, "must be frozen");
maybe_initialize(); // get non-null handles, even if we have no oops
nm->copy_values(_handles);
}
template <class T> T ValueRecorder<T>::at(int index) { // there is always a NULL virtually present as first object if (index == null_index) return NULL; return _handles->at(index - first_index);
}
template <class T> int ValueRecorder<T>::add_handle(T h, bool make_findable) {
assert(!_complete, "cannot allocate more elements after size query");
maybe_initialize(); // indexing uses 1 as an origin--0 means null int index = _handles->length() + first_index;
_handles->append(h);
// Support correct operation of find_index().
assert(!(make_findable && !is_real(h)), "nulls are not findable"); if (make_findable) { // This index may be returned from find_index(). if (_indexes != NULL) { int* cloc = _indexes->cache_location(h);
_indexes->set_cache_location_index(cloc, index);
} elseif (index == index_cache_threshold && _arena != NULL) {
_indexes = new(_arena) IndexCache<T>(); for (int i = 0; i < _handles->length(); i++) { // Load the cache with pre-existing elements. int index0 = i + first_index; if (_no_finds->contains(index0)) continue; int* cloc = _indexes->cache_location(_handles->at(i));
_indexes->set_cache_location_index(cloc, index0);
}
}
} elseif (is_real(h)) { // Remember that this index is not to be returned from find_index(). // This case is rare, because most or all uses of allocate_index pass // an argument of NULL or Universe::non_oop_word. // Thus, the expected length of _no_finds is zero.
_no_finds->append(index);
}
return index;
}
template <class T> int ValueRecorder<T>::maybe_find_index(T h) {
debug_only(_find_index_calls++);
assert(!_complete, "cannot allocate more elements after size query");
maybe_initialize(); if (h == NULL) return null_index;
assert(is_real(h), "must be valid"); int* cloc = (_indexes == NULL)? NULL: _indexes->cache_location(h); if (cloc != NULL) { int cindex = _indexes->cache_location_index(cloc); if (cindex == 0) { return -1; // We know this handle is completely new.
} if (cindex >= first_index && _handles->at(cindex - first_index) == h) {
debug_only(_hit_indexes++); return cindex;
} if (!_indexes->cache_location_collision(cloc)) { return -1; // We know the current cache occupant is unique to that cloc.
}
}
// Not found in cache, due to a cache collision. (Or, no cache at all.) // Do a linear search, most recent to oldest. for (int i = _handles->length() - 1; i >= 0; i--) { if (_handles->at(i) == h) { int findex = i + first_index; if (_no_finds->contains(findex)) continue; // oops; skip this one if (cloc != NULL) {
_indexes->set_cache_location_index(cloc, findex);
}
debug_only(_missed_indexes++); return findex;
}
} return -1;
}
// Explicitly instantiate these types templateclass ValueRecorder<Metadata*>; templateclass ValueRecorder<jobject>;
void ObjectLookup::maybe_resort() { // The values are kept sorted by address which may be invalidated // after a GC, so resort if a GC has occurred since last time. if (_gc_count != Universe::heap()->total_collections()) {
_gc_count = Universe::heap()->total_collections();
_values.sort(sort_by_address);
}
}
int ObjectLookup::sort_by_address(oop a, oop b) { // oopDesc::compare returns the opposite of what this function returned return -(oopDesc::compare(a, b));
}
int ObjectLookup::sort_by_address(ObjectEntry* a, ObjectEntry* b) { return sort_by_address(a->oop_value(), b->oop_value());
}
int ObjectLookup::sort_oop_by_address(oop const& a, ObjectEntry const& b) { return sort_by_address(a, b.oop_value());
}
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