Reland "Make sure that memory reducer makes progress in incremental marking""

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/base/bits.h"
 #include "src/base/once.h"
@@ skipping 4604 matching lines @@
 
   if (ShouldReduceMemory() ||
       ((allocation_throughput != 0) &&
        (allocation_throughput < kLowAllocationThroughput))) {
     new_space_.Shrink();
     UncommitFromSpace();
   }
 }
 
 
+void Heap::FinalizeIncrementalMarkingIfComplete(const char* comment) {
+  if (FLAG_overapproximate_weak_closure && incremental_marking()->IsMarking() &&
+      (incremental_marking()->IsReadyToOverApproximateWeakClosure() ||
+       (!incremental_marking()->weak_closure_was_overapproximated() &&
+        mark_compact_collector_.marking_deque()->IsEmpty()))) {
+    OverApproximateWeakClosure(comment);
+  } else if (incremental_marking()->IsComplete() ||
+             (mark_compact_collector_.marking_deque()->IsEmpty())) {
+    CollectAllGarbage(current_gc_flags_, comment);
+  }
+}
+
+
 bool Heap::TryFinalizeIdleIncrementalMarking(
     double idle_time_in_ms, size_t size_of_objects,
     size_t final_incremental_mark_compact_speed_in_bytes_per_ms) {
-  if (FLAG_overapproximate_weak_closure &&
+  if (FLAG_overapproximate_weak_closure && incremental_marking()->IsMarking() &&
       (incremental_marking()->IsReadyToOverApproximateWeakClosure() ||
        (!incremental_marking()->weak_closure_was_overapproximated() &&
         mark_compact_collector_.marking_deque()->IsEmpty() &&
         gc_idle_time_handler_.ShouldDoOverApproximateWeakClosure(
             static_cast<size_t>(idle_time_in_ms))))) {
     OverApproximateWeakClosure(
         "Idle notification: overapproximate weak closure");
     return true;
   } else if (incremental_marking()->IsComplete() ||
              (mark_compact_collector_.marking_deque()->IsEmpty() &&
@@ skipping 2019 matching lines @@
     *object_sub_type = "CODE_AGE/" #name;                              \
     return true;
     CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME)
 #undef COMPARE_AND_RETURN_NAME
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8