HeapRegion* OldGCAllocRegion::release() {
HeapRegion* cur = get();
if (cur != NULL) {
// Determine how far we are from the next card boundary. If it is smaller than
// the minimum object size we can allocate into, expand into the next card.
HeapWord* top = cur->top();
HeapWord* aligned_top = (HeapWord*)align_ptr_up(top, G1BlockOffsetSharedArray::N_bytes);
size_t to_allocate_words = pointer_delta(aligned_top, top, HeapWordSize);
if (to_allocate_words != 0) {
// We are not at a card boundary. Fill up, possibly into the next, taking the
// end of the region and the minimum object size into account.
to_allocate_words = MIN2(pointer_delta(cur->end(), cur->top(), HeapWordSize),
MAX2(to_allocate_words, G1CollectedHeap::min_fill_size()));
// Skip allocation if there is not enough space to allocate even the smallest
// possible object. In this case this region will not be retained, so the
// original problem cannot occur.
if (to_allocate_words >= G1CollectedHeap::min_fill_size()) {
HeapWord* dummy = attempt_allocation(to_allocate_words, true /* bot_updates */);
CollectedHeap::fill_with_object(dummy, to_allocate_words);
}
}
}
return G1AllocRegion::release();
}
inline HeapWord* G1AllocRegion::attempt_allocation_locked(size_t word_size,
bool bot_updates) {
// First we have to tedo the allocation, assuming we're holding the
// appropriate lock, in case another thread changed the region while
// we were waiting to get the lock.
HeapWord* result = attempt_allocation(word_size, bot_updates);
if (result != NULL) {
return result;
}
retire(true /* fill_up */);
result = new_alloc_region_and_allocate(word_size, false /* force */);
if (result != NULL) {
trace("alloc locked (second attempt)", word_size, result);
return result;
}
trace("alloc locked failed", word_size);
return NULL;
}
