Explicitly track whether incremental marking was activated

src/heap/incremental-marking.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/v8.h"
 
 #include "src/heap/incremental-marking.h"
 
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
 #include "src/conversions.h"
 #include "src/heap/objects-visiting.h"
 #include "src/heap/objects-visiting-inl.h"
 
 namespace v8 {
 namespace internal {
 
 
 IncrementalMarking::IncrementalMarking(Heap* heap)
     : heap_(heap),
       state_(STOPPED),
       steps_count_(0),
       old_generation_space_available_at_start_of_incremental_(0),
       old_generation_space_used_at_start_of_incremental_(0),
       should_hurry_(false),
       marking_speed_(0),
       allocated_(0),
       idle_marking_delay_counter_(0),
       no_marking_scope_depth_(0),
-      unscanned_bytes_of_large_object_(0) {}
+      unscanned_bytes_of_large_object_(0),
+      was_activated_(false) {}
 
 
 void IncrementalMarking::RecordWriteSlow(HeapObject* obj, Object** slot,
                                          Object* value) {
   if (BaseRecordWrite(obj, slot, value) && slot != NULL) {
     MarkBit obj_bit = Marking::MarkBitFrom(obj);
     if (Marking::IsBlack(obj_bit)) {
       // Object is not going to be rescanned we need to record the slot.
       heap_->mark_compact_collector()->RecordSlot(HeapObject::RawField(obj, 0),
                                                   slot, value);
@@ skipping 375 matching lines @@
     lop = lop->next_page();
   }
 }
 
 
 bool IncrementalMarking::ShouldActivate() {
   return WorthActivating() && heap_->NextGCIsLikelyToBeFull();
 }
 
 
+bool IncrementalMarking::WasActivated() { return was_activated_; }
+
+
 bool IncrementalMarking::WorthActivating() {
 #ifndef DEBUG
   static const intptr_t kActivationThreshold = 8 * MB;
 #else
   // TODO(gc) consider setting this to some low level so that some
   // debug tests run with incremental marking and some without.
   static const intptr_t kActivationThreshold = 0;
 #endif
   // Only start incremental marking in a safe state: 1) when incremental
   // marking is turned on, 2) when we are currently not in a GC, and
@@ skipping 47 matching lines @@
     PrintF("[IncrementalMarking] Start\n");
   }
   DCHECK(FLAG_incremental_marking);
   DCHECK(FLAG_incremental_marking_steps);
   DCHECK(state_ == STOPPED);
   DCHECK(heap_->gc_state() == Heap::NOT_IN_GC);
   DCHECK(!heap_->isolate()->serializer_enabled());
 
   ResetStepCounters();
 
+  was_activated_ = true;
+
   if (!heap_->mark_compact_collector()->sweeping_in_progress()) {
     StartMarking(flag);
   } else {
     if (FLAG_trace_incremental_marking) {
       PrintF("[IncrementalMarking] Start sweeping.\n");
     }
     state_ = SWEEPING;
   }
 
   heap_->new_space()->LowerInlineAllocationLimit(kAllocatedThreshold);
@@ skipping 275 matching lines @@
   set_should_hurry(true);
   if (FLAG_trace_incremental_marking) {
     PrintF("[IncrementalMarking] Complete (normal).\n");
   }
   if (action == GC_VIA_STACK_GUARD) {
     heap_->isolate()->stack_guard()->RequestGC();
   }
 }
 
 
+void IncrementalMarking::Epilogue() { was_activated_ = false; }
+
+
 void IncrementalMarking::OldSpaceStep(intptr_t allocated) {
   if (IsStopped() && ShouldActivate()) {
     // TODO(hpayer): Let's play safe for now, but compaction should be
     // in principle possible.
     Start(PREVENT_COMPACTION);
   } else {
     Step(allocated * kFastMarking / kInitialMarkingSpeed, GC_VIA_STACK_GUARD);
   }
 }
 
@@ skipping 177 matching lines @@
 void IncrementalMarking::IncrementIdleMarkingDelayCounter() {
   idle_marking_delay_counter_++;
 }
 
 
 void IncrementalMarking::ClearIdleMarkingDelayCounter() {
   idle_marking_delay_counter_ = 0;
 }
 }
 }  // namespace v8::internal