Put incremental code flushing behind a flag.

src/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1453 matching lines @@
       MarkCompactMarkingVisitor::MarkInlinedFunctionsCode(heap(),
                                                           frame->LookupCode());
     }
   }
 }
 
 
 void MarkCompactCollector::PrepareForCodeFlushing() {
   ASSERT(heap() == Isolate::Current()->heap());
 
+  // Enable code flushing for non-incremental cycles.
+  if (FLAG_flush_code && !FLAG_flush_code_incrementally) {
+    EnableCodeFlushing(!was_marked_incrementally_);
+  }
+
   // If code flushing is disabled, there is no need to prepare for it.
   if (!is_code_flushing_enabled()) return;
 
   // Ensure that empty descriptor array is marked. Method MarkDescriptorArray
   // relies on it being marked before any other descriptor array.
   HeapObject* descriptor_array = heap()->empty_descriptor_array();
   MarkBit descriptor_array_mark = Marking::MarkBitFrom(descriptor_array);
   MarkObject(descriptor_array, descriptor_array_mark);
 
   // Make sure we are not referencing the code from the stack.
@@ skipping 542 matching lines @@
   MarkCompactWeakObjectRetainer mark_compact_object_retainer;
   heap()->ProcessWeakReferences(&mark_compact_object_retainer);
 
   // Remove object groups after marking phase.
   heap()->isolate()->global_handles()->RemoveObjectGroups();
   heap()->isolate()->global_handles()->RemoveImplicitRefGroups();
 
   // Flush code from collected candidates.
   if (is_code_flushing_enabled()) {
     code_flusher_->ProcessCandidates();
+    // If incremental marker does not support code flushing, we need to
+    // disable it before incremental marking steps for next cycle.
+    if (FLAG_flush_code && !FLAG_flush_code_incrementally) {
+      EnableCodeFlushing(false);
+    }
   }
 
   if (!FLAG_watch_ic_patching) {
     // Clean up dead objects from the runtime profiler.
     heap()->isolate()->runtime_profiler()->RemoveDeadSamples();
   }
 
   if (FLAG_track_gc_object_stats) {
     heap()->CheckpointObjectStats();
   }
@@ skipping 1554 matching lines @@
   // detect whether unmarked map became dead in this collection or in one
   // of the previous ones.
   SweepSpace(heap()->map_space(), PRECISE);
 
   // Deallocate unmarked objects and clear marked bits for marked objects.
   heap_->lo_space()->FreeUnmarkedObjects();
 }
 
 
 void MarkCompactCollector::EnableCodeFlushing(bool enable) {
+#ifdef ENABLE_DEBUGGER_SUPPORT
+  if (heap()->isolate()->debug()->IsLoaded() ||
+      heap()->isolate()->debug()->has_break_points()) {
+    enable = false;
+  }
+#endif
+
   if (enable) {
     if (code_flusher_ != NULL) return;
     code_flusher_ = new CodeFlusher(heap()->isolate());
   } else {
     if (code_flusher_ == NULL) return;
     delete code_flusher_;
     code_flusher_ = NULL;
   }
 }
 
@@ skipping 168 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal