diff options
| -rw-r--r-- | runtime/gc/collector/mark_compact.cc | 65 |
1 files changed, 41 insertions, 24 deletions
diff --git a/runtime/gc/collector/mark_compact.cc b/runtime/gc/collector/mark_compact.cc index 07c7909fea..169a6e7693 100644 --- a/runtime/gc/collector/mark_compact.cc +++ b/runtime/gc/collector/mark_compact.cc @@ -4853,33 +4853,45 @@ void MarkCompact::FinishPhase(bool performed_compaction) { if (use_generational_) { { ReaderMutexLock mu(thread_running_gc_, *Locks::mutator_lock_); - // We need to retain class-after-object map for old-gen as that won't - // be created in next young-gc. - // Find the first class which is getting promoted to old-gen. + // We need to retain and update class-after-object map for old-gen as + // that won't be created in next young-gc. + // Jump to the first class which is getting promoted to old-gen. Since + // it is not compacted, references into old-gen don't need to be udated. + // All pairs in mid-gen will be updated with post-compact addresses and + // retained, as mid-gen is getting consumed into old-gen now. All pairs + // after mid-gen will be erased as they are not required in next GC cycle. auto iter = class_after_obj_map_.lower_bound( ObjReference::FromMirrorPtr(reinterpret_cast<mirror::Object*>(old_gen_end_))); while (iter != class_after_obj_map_.end()) { - // As 'mid_gen_end_' is where our old-gen will end now, compute - // compacted addresses of <class, object> for comparisons and updating - // in the map. - mirror::Object* compacted_klass = nullptr; - mirror::Object* compacted_obj = nullptr; mirror::Object* klass = iter->first.AsMirrorPtr(); mirror::Object* obj = iter->second.AsMirrorPtr(); DCHECK_GT(klass, obj); - if (reinterpret_cast<uint8_t*>(klass) < black_allocations_begin_) { - DCHECK(moving_space_bitmap_->Test(klass)); - DCHECK(moving_space_bitmap_->Test(obj)); + // Black allocations begin after marking-pause. Therefore, we cannot + // have a situation wherein class is allocated after the pause while its + // object is before. + if (reinterpret_cast<uint8_t*>(klass) >= black_allocations_begin_) { + for (auto it = iter; it != class_after_obj_map_.end(); it++) { + DCHECK_GE(reinterpret_cast<uint8_t*>(it->second.AsMirrorPtr()), + black_allocations_begin_); + } + class_after_obj_map_.erase(iter, class_after_obj_map_.end()); + break; + } + + DCHECK(moving_space_bitmap_->Test(klass)); + DCHECK(moving_space_bitmap_->Test(obj)); + // As 'mid_gen_end_' is where our old-gen will end now, compute compacted + // addresses of <class, object> for comparisons and updating in the map. + mirror::Object* compacted_klass = klass; + mirror::Object* compacted_obj = obj; + if (performed_compaction) { compacted_klass = PostCompactAddress(klass, old_gen_end_, moving_space_end_); compacted_obj = PostCompactAddress(obj, old_gen_end_, moving_space_end_); DCHECK_GT(compacted_klass, compacted_obj); } - // An object (and therefore its class as well) after mid-gen will be - // considered again during marking in next GC. So remove all entries - // from this point onwards. - if (compacted_obj == nullptr || reinterpret_cast<uint8_t*>(compacted_obj) >= mid_gen_end_) { - class_after_obj_map_.erase(iter, class_after_obj_map_.end()); - break; + if (reinterpret_cast<uint8_t*>(compacted_obj) >= mid_gen_end_) { + iter = class_after_obj_map_.erase(iter); + continue; } else if (mid_to_old_promo_bit_vec_.get() != nullptr) { if (reinterpret_cast<uint8_t*>(compacted_klass) >= old_gen_end_) { DCHECK(mid_to_old_promo_bit_vec_->IsBitSet( @@ -4890,11 +4902,15 @@ void MarkCompact::FinishPhase(bool performed_compaction) { (reinterpret_cast<uint8_t*>(compacted_klass) - old_gen_end_) / kAlignment)); } } - auto nh = class_after_obj_map_.extract(iter++); - nh.key() = ObjReference::FromMirrorPtr(compacted_klass); - nh.mapped() = ObjReference::FromMirrorPtr(compacted_obj); - auto success = class_after_obj_map_.insert(iter, std::move(nh)); - CHECK_EQ(success->first.AsMirrorPtr(), compacted_klass); + if (performed_compaction) { + auto nh = class_after_obj_map_.extract(iter++); + nh.key() = ObjReference::FromMirrorPtr(compacted_klass); + nh.mapped() = ObjReference::FromMirrorPtr(compacted_obj); + auto success = class_after_obj_map_.insert(iter, std::move(nh)); + CHECK_EQ(success->first.AsMirrorPtr(), compacted_klass); + } else { + iter++; + } } // Dirty the cards for objects captured from native-roots during marking-phase. @@ -4907,9 +4923,10 @@ void MarkCompact::FinishPhase(bool performed_compaction) { // need to be tracked. // The vector contains pre-compact object references whereas // 'mid_gen_end_' is post-compact boundary. So compare against - // pist-compact object reference. + // post-compact object reference. mirror::Object* compacted_obj = - PostCompactAddress(obj, black_dense_end_, moving_space_end_); + performed_compaction ? PostCompactAddress(obj, black_dense_end_, moving_space_end_) + : obj; if (reinterpret_cast<uint8_t*>(compacted_obj) < mid_gen_end_) { card_table->MarkCard(compacted_obj); } |