[heap] pause observers during mark-compact

src/heap/spaces.h

 // Copyright 2011 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.
 
 #ifndef V8_HEAP_SPACES_H_
 #define V8_HEAP_SPACES_H_
 
 #include "src/allocation.h"
 #include "src/atomic-utils.h"
 #include "src/base/atomicops.h"
@@ skipping 2737 matching lines @@
 
   // Allows observation of inline allocation. The observer->Step() method gets
   // called after every step_size bytes have been allocated (approximately).
   // This works by adjusting the allocation limit to a lower value and adjusting
   // it after each step.
   void AddInlineAllocationObserver(InlineAllocationObserver* observer);
 
   // Removes a previously installed observer.
   void RemoveInlineAllocationObserver(InlineAllocationObserver* observer);
 
-  void PauseInlineAllocationObservers();
-  void ResumeInlineAllocationObservers();
-
   void DisableInlineAllocationSteps() {
     top_on_previous_step_ = 0;
     UpdateInlineAllocationLimit(0);
   }
 
   // Get the extent of the inactive semispace (for use as a marking stack,
   // or to zap it). Notice: space-addresses are not necessarily on the
   // same page, so FromSpaceStart() might be above FromSpaceEnd().
   Address FromSpacePageLow() { return from_space_.page_low(); }
   Address FromSpacePageHigh() { return from_space_.page_high(); }
@@ skipping 101 matching lines @@
   // If we are doing inline allocation in steps, this method performs the 'step'
   // operation. top is the memory address of the bump pointer at the last
   // inline allocation (i.e. it determines the numbers of bytes actually
   // allocated since the last step.) new_top is the address of the bump pointer
   // where the next byte is going to be allocated from. top and new_top may be
   // different when we cross a page boundary or reset the space.
   void InlineAllocationStep(Address top, Address new_top, Address soon_object,
                             size_t size);
   intptr_t GetNextInlineAllocationStepSize();
   void StartNextInlineAllocationStep();
+  void PauseInlineAllocationObservers();
+  void ResumeInlineAllocationObservers();
 
+  friend class PauseInlineAllocationObserversScope;
   friend class SemiSpaceIterator;
 };
 
+class PauseInlineAllocationObserversScope {
+ public:
+  explicit PauseInlineAllocationObserversScope(NewSpace* new_space)
+      : new_space_(new_space) {
+    new_space_->PauseInlineAllocationObservers();
+  }
+  ~PauseInlineAllocationObserversScope() {
+    new_space_->ResumeInlineAllocationObservers();
+  }
+
+ private:
+  NewSpace* new_space_;
+  DISALLOW_COPY_AND_ASSIGN(PauseInlineAllocationObserversScope);
+};
+
 // -----------------------------------------------------------------------------
 // Compaction space that is used temporarily during compaction.
 
 class CompactionSpace : public PagedSpace {
  public:
   CompactionSpace(Heap* heap, AllocationSpace id, Executability executable)
       : PagedSpace(heap, id, executable) {}
 
   // Adds external memory starting at {start} of {size_in_bytes} to the space.
   void AddExternalMemory(Address start, int size_in_bytes) {
@@ skipping 244 matching lines @@
     count = 0;
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_H_