GC: Refactor public incremental marking interface in heap

src/heap/incremental-marking.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_INCREMENTAL_MARKING_H_
 #define V8_HEAP_INCREMENTAL_MARKING_H_
 
 
 #include "src/execution.h"
 #include "src/heap/mark-compact.h"
 #include "src/objects.h"
 
 namespace v8 {
 namespace internal {
 
 
 class IncrementalMarking {
  public:
   enum State { STOPPED, SWEEPING, MARKING, COMPLETE };
 
   enum CompletionAction { GC_VIA_STACK_GUARD, NO_GC_VIA_STACK_GUARD };
 
   enum ForceMarkingAction { FORCE_MARKING, DO_NOT_FORCE_MARKING };
 
   enum ForceCompletionAction { FORCE_COMPLETION, DO_NOT_FORCE_COMPLETION };
 
   enum GCRequestType { COMPLETE_MARKING, OVERAPPROXIMATION };
 
+  struct StepActions {
+    StepActions(
+        CompletionAction complete_action_ = NO_GC_VIA_STACK_GUARD,

[ulan, 2015/08/04 13:13:31]

For readability of the call site, I would prefer passing flags explicitly in the
main constructor and making static constructor function with descriptive name
for specific flag combinations that are frequently used.

[Michael Lippautz, 2015/08/04 13:55:35]

Done.

+        ForceMarkingAction force_marking_ = DO_NOT_FORCE_MARKING,
+        ForceCompletionAction force_completion_ = DO_NOT_FORCE_COMPLETION)
+        : completion_action(complete_action_),
+          force_marking(force_marking_),
+          force_completion(force_completion_) {}
+
+    CompletionAction completion_action;
+    ForceMarkingAction force_marking;
+    ForceCompletionAction force_completion;
+  };
+
   explicit IncrementalMarking(Heap* heap);
 
   static void Initialize();
 
   State state() {
     DCHECK(state_ == STOPPED || FLAG_incremental_marking);
     return state_;
   }
 
   bool should_hurry() { return should_hurry_; }
@@ skipping 21 matching lines @@
   }
 
   GCRequestType request_type() const { return request_type_; }
 
   bool CanBeActivated();
 
   bool ShouldActivateEvenWithoutIdleNotification();
 
   bool WasActivated();
 
-  void Start(int mark_compact_flags);
+  void Start(int mark_compact_flags,
+             const GCCallbackFlags gc_callback_flags = kNoGCCallbackFlags);
 
   void Stop();
 
   void MarkObjectGroups();
 
   void UpdateMarkingDequeAfterScavenge();
 
   void Hurry();
 
   void Finalize();
@@ skipping 97 matching lines @@
   }
 
   void ClearIdleMarkingDelayCounter();
 
   bool IsIdleMarkingDelayCounterLimitReached();
 
   INLINE(static void MarkObject(Heap* heap, HeapObject* object));
 
   Heap* heap() const { return heap_; }
 
+  GCCallbackFlags CallbackFlags() const { return gc_callback_flags_; }
+
  private:
   int64_t SpaceLeftInOldSpace();
 
   void SpeedUp();
 
   void ResetStepCounters();
 
   void StartMarking();
 
   void ActivateIncrementalWriteBarrier(PagedSpace* space);
@@ skipping 38 matching lines @@
   int unscanned_bytes_of_large_object_;
 
   bool was_activated_;
 
   bool weak_closure_was_overapproximated_;
 
   int weak_closure_approximation_rounds_;
 
   GCRequestType request_type_;
 
+  GCCallbackFlags gc_callback_flags_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_INCREMENTAL_MARKING_H_