[heap] Refactor incremental marking step.

src/heap/heap.cc

 // 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.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 918 matching lines @@
     const double pressure =
         static_cast<double>(external_memory_ -
                             external_memory_at_last_mark_compact_ -
                             kExternalAllocationSoftLimit) /
         external_memory_hard_limit();
     DCHECK_GE(1, pressure);
     const double kMaxStepSizeOnExternalLimit = 25;
     const double deadline = MonotonicallyIncreasingTimeInMs() +
                             pressure * kMaxStepSizeOnExternalLimit;
     incremental_marking()->AdvanceIncrementalMarking(
-        deadline,
-        IncrementalMarking::StepActions(IncrementalMarking::GC_VIA_STACK_GUARD,
-                                        IncrementalMarking::FORCE_MARKING,
-                                        IncrementalMarking::FORCE_COMPLETION));
+        deadline, IncrementalMarking::GC_VIA_STACK_GUARD,
+        IncrementalMarking::FORCE_COMPLETION);
   }
 }
 
 
 void Heap::EnsureFillerObjectAtTop() {
   // There may be an allocation memento behind objects in new space. Upon
   // evacuation of a non-full new space (or if we are on the last page) there
   // may be uninitialized memory behind top. We fill the remainder of the page
   // with a filler.
   Address to_top = new_space_.top();
@@ skipping 96 matching lines @@
   }
 
   if (collector == MARK_COMPACTOR &&
       (gc_callback_flags & (kGCCallbackFlagForced |
                             kGCCallbackFlagCollectAllAvailableGarbage)) != 0) {
     isolate()->CountUsage(v8::Isolate::kForcedGC);
   }
 
   // Start incremental marking for the next cycle. The heap snapshot
   // generator needs incremental marking to stay off after it aborted.
-  if (!ShouldAbortIncrementalMarking() && incremental_marking()->IsStopped() &&
-      incremental_marking()->ShouldActivateEvenWithoutIdleNotification()) {
-    StartIncrementalMarking(kNoGCFlags, kNoGCCallbackFlags, "GC epilogue");
+  if (!ShouldAbortIncrementalMarking()) {
+    StartIncrementalMarkingIfNeeded(kNoGCFlags, kNoGCCallbackFlags,
+                                    "GC epilogue");
   }
 
   return next_gc_likely_to_collect_more;
 }
 
 
 int Heap::NotifyContextDisposed(bool dependant_context) {
   if (!dependant_context) {
     tracer()->ResetSurvivalEvents();
     old_generation_size_configured_ = false;
@@ skipping 15 matching lines @@
 
 void Heap::StartIncrementalMarking(int gc_flags,
                                    const GCCallbackFlags gc_callback_flags,
                                    const char* reason) {
   DCHECK(incremental_marking()->IsStopped());
   set_current_gc_flags(gc_flags);
   current_gc_callback_flags_ = gc_callback_flags;
   incremental_marking()->Start(reason);
 }
 
+void Heap::StartIncrementalMarkingIfNeeded(
+    int gc_flags, const GCCallbackFlags gc_callback_flags, const char* reason) {
+  if (incremental_marking()->IsStopped() &&
+      incremental_marking()->ShouldActivateEvenWithoutIdleNotification()) {
+    StartIncrementalMarking(gc_flags, gc_callback_flags, reason);
+  }
+}
 
 void Heap::StartIdleIncrementalMarking() {
   gc_idle_time_handler_->ResetNoProgressCounter();
   StartIncrementalMarking(kReduceMemoryFootprintMask, kNoGCCallbackFlags,
                           "idle");
 }
 
 
 void Heap::MoveElements(FixedArray* array, int dst_index, int src_index,
                         int len) {
@@ skipping 5357 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8