[heap] Prefer mark-compact over scavenger if 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/ast/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 246 matching lines @@
     isolate_->counters()->gc_compactor_caused_by_request()->Increment();
     *reason = "GC in old space requested";
     return MARK_COMPACTOR;
   }
 
   if (FLAG_gc_global || (FLAG_stress_compaction && (gc_count_ & 1) != 0)) {
     *reason = "GC in old space forced by flags";
     return MARK_COMPACTOR;
   }
 
+  if (incremental_marking()->NeedsFinalization() &&
+      OldGenerationSpaceAvailable() == 0) {
+    *reason = "Incremental marking needs finalization";
+    return MARK_COMPACTOR;
+  }
+
   // Is there enough space left in OLD to guarantee that a scavenge can
   // succeed?
   //
   // Note that MemoryAllocator->MaxAvailable() undercounts the memory available
   // for object promotion. It counts only the bytes that the memory
   // allocator has not yet allocated from the OS and assigned to any space,
   // and does not count available bytes already in the old space or code
   // space.  Undercounting is safe---we may get an unrequested full GC when
   // a scavenge would have succeeded.
   if (memory_allocator()->MaxAvailable() <= new_space_->Size()) {
@@ skipping 6208 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8