[heap] Evacuation for young generation

src/heap/mark-compact.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_MARK_COMPACT_H_
 #define V8_HEAP_MARK_COMPACT_H_
 
 #include <deque>
 
 #include "src/base/bits.h"
@@ skipping 287 matching lines @@
   virtual void SetUp() = 0;
   virtual void TearDown() = 0;
   virtual void CollectGarbage() = 0;
 
   inline Heap* heap() const { return heap_; }
   inline Isolate* isolate() { return heap()->isolate(); }
 
  protected:
   explicit MarkCompactCollectorBase(Heap* heap) : heap_(heap) {}
 
+  virtual void ProcessMarkingDeque() = 0;

[Hannes Payer (out of office), 2017/05/03 14:44:53]

Can you move the comments from MarkCompacts to the abstract class and add
specific details in comments to the implementations.

[Michael Lippautz, 2017/05/03 15:08:03]

Done.

+  virtual void EmptyMarkingDeque() = 0;
   virtual void MarkLiveObjects() = 0;
+  virtual void ClearNonLiveReferences() = 0;
+  virtual void EvacuatePrologue() = 0;
+  virtual void EvacuateEpilogue() = 0;
+  virtual void Evacuate() = 0;
+  virtual void EvacuatePagesInParallel() = 0;
+  virtual void UpdatePointersAfterEvacuation() = 0;
 
   // The number of parallel compaction tasks, including the main thread.
   int NumberOfParallelCompactionTasks(int pages, intptr_t live_bytes);
 
   template <class Evacuator, class Collector>
   void CreateAndExecuteEvacuationTasks(
       Collector* collector, PageParallelJob<EvacuationJobTraits>* job,
-      RecordMigratedSlotVisitor* record_visitor, const intptr_t live_bytes,
+      RecordMigratedSlotVisitor* record_visitor,
+      MigrationObserver* migration_observer, const intptr_t live_bytes,
       const int& abandoned_pages);
 
   Heap* heap_;
 };
 
 // Collector for young-generation only.
 class MinorMarkCompactCollector final : public MarkCompactCollectorBase {
  public:
   explicit MinorMarkCompactCollector(Heap* heap)
-      : MarkCompactCollectorBase(heap), marking_deque_(heap) {}
+      : MarkCompactCollectorBase(heap),
+        marking_deque_(heap),
+        page_parallel_job_semaphore_(0) {}
 
   MarkingState marking_state(HeapObject* object) const override {
     return MarkingState::External(object);
   }
 
   MarkingState marking_state(MemoryChunk* chunk) const override {
     return MarkingState::External(chunk);
   }
 
   void SetUp() override;
   void TearDown() override;
   void CollectGarbage() override;
 
  private:
   class RootMarkingVisitor;
 
   inline MarkingDeque* marking_deque() { return &marking_deque_; }
 
   V8_INLINE void MarkObject(HeapObject* obj);
   V8_INLINE void PushBlack(HeapObject* obj);
 
   SlotCallbackResult CheckAndMarkObject(Heap* heap, Address slot_address);
   void MarkLiveObjects() override;
-  void ProcessMarkingDeque();
-  void EmptyMarkingDeque();
+  void ProcessMarkingDeque() override;
+  void EmptyMarkingDeque() override;
+  void ClearNonLiveReferences() override;
+
+  void EvacuatePrologue() override;
+  void EvacuateEpilogue() override;
+  void Evacuate() override;
+  void EvacuatePagesInParallel() override;
+  void UpdatePointersAfterEvacuation() override;
 
   MarkingDeque marking_deque_;
+  base::Semaphore page_parallel_job_semaphore_;
+  List<Page*> new_space_evacuation_pages_;
 
   friend class StaticYoungGenerationMarkingVisitor;
 };
 
 // Collector for young and old generation.
 class MarkCompactCollector final : public MarkCompactCollectorBase {
  public:
   class RootMarkingVisitor;
 
   class Sweeper {
@@ skipping 210 matching lines @@
 
   // Mark the heap roots and all objects reachable from them.
   void MarkRoots(RootMarkingVisitor* visitor);
 
   // Mark the string table specially.  References to internalized strings from
   // the string table are weak.
   void MarkStringTable(RootMarkingVisitor* visitor);
 
   // Mark objects reachable (transitively) from objects in the marking stack
   // or overflowed in the heap.
-  void ProcessMarkingDeque();
+  void ProcessMarkingDeque() override;
 
   // Mark objects reachable (transitively) from objects in the marking stack
   // or overflowed in the heap.  This respects references only considered in
   // the final atomic marking pause including the following:
   //    - Processing of objects reachable through Harmony WeakMaps.
   //    - Objects reachable due to host application logic like object groups,
   //      implicit references' groups, or embedder heap tracing.
   void ProcessEphemeralMarking(bool only_process_harmony_weak_collections);
 
   // If the call-site of the top optimized code was not prepared for
   // deoptimization, then treat the maps in the code as strong pointers,
   // otherwise a map can die and deoptimize the code.
   void ProcessTopOptimizedFrame(RootMarkingVisitor* visitor);
 
   // Collects a list of dependent code from maps embedded in optimize code.
   DependentCode* DependentCodeListFromNonLiveMaps();
 
   // Mark objects reachable (transitively) from objects in the marking
   // stack.  This function empties the marking stack, but may leave
   // overflowed objects in the heap, in which case the marking stack's
   // overflow flag will be set.
-  void EmptyMarkingDeque();
+  void EmptyMarkingDeque() override;
 
   // Refill the marking stack with overflowed objects from the heap.  This
   // function either leaves the marking stack full or clears the overflow
   // flag on the marking stack.
   void RefillMarkingDeque();
 
   // Helper methods for refilling the marking stack by discovering grey objects
   // on various pages of the heap. Used by {RefillMarkingDeque} only.
   template <class T>
   void DiscoverGreyObjectsWithIterator(T* it);
   void DiscoverGreyObjectsOnPage(MemoryChunk* p);
   void DiscoverGreyObjectsInSpace(PagedSpace* space);
   void DiscoverGreyObjectsInNewSpace();
 
   // Callback function for telling whether the object *p is an unmarked
   // heap object.
   static bool IsUnmarkedHeapObject(Object** p);
 
   // Clear non-live references in weak cells, transition and descriptor arrays,
   // and deoptimize dependent code of non-live maps.
-  void ClearNonLiveReferences();
+  void ClearNonLiveReferences() override;
   void MarkDependentCodeForDeoptimization(DependentCode* list);
   // Find non-live targets of simple transitions in the given list. Clear
   // transitions to non-live targets and if needed trim descriptors arrays.
   void ClearSimpleMapTransitions(Object* non_live_map_list);
   void ClearSimpleMapTransition(Map* map, Map* dead_transition);
   // Compact every array in the global list of transition arrays and
   // trim the corresponding descriptor array if a transition target is non-live.
   void ClearFullMapTransitions();
   bool CompactTransitionArray(Map* map, TransitionArray* transitions,
                               DescriptorArray* descriptors);
@@ skipping 18 matching lines @@
                       DependentCode** dependent_code_list);
   void AbortWeakCells();
 
   void AbortTransitionArrays();
 
   // Starts sweeping of spaces by contributing on the main thread and setting
   // up other pages for sweeping. Does not start sweeper tasks.
   void StartSweepSpaces();
   void StartSweepSpace(PagedSpace* space);
 
-  void EvacuatePrologue();
-  void EvacuateEpilogue();
-  void EvacuatePagesInParallel();
-
-  void EvacuateNewSpaceAndCandidates();
-
-  void UpdatePointersAfterEvacuation();
+  void EvacuatePrologue() override;
+  void EvacuateEpilogue() override;
+  void Evacuate() override;
+  void EvacuatePagesInParallel() override;
+  void UpdatePointersAfterEvacuation() override;
 
   void ReleaseEvacuationCandidates();
 
   base::Semaphore page_parallel_job_semaphore_;
 
 #ifdef DEBUG
   enum CollectorState {
     IDLE,
     PREPARE_GC,
     MARK_LIVE_OBJECTS,
@@ skipping 52 matching lines @@
   ~EvacuationScope() { collector_->set_evacuation(false); }
 
  private:
   MarkCompactCollector* collector_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_MARK_COMPACT_H_