Line data    Source code

       1             : // Copyright 2018 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #ifndef V8_OBJECTS_FEEDBACK_CELL_H_
       6             : #define V8_OBJECTS_FEEDBACK_CELL_H_
       7             : 
       8             : #include "src/objects/struct.h"
       9             : 
      10             : // Has to be the last include (doesn't have include guards):
      11             : #include "src/objects/object-macros.h"
      12             : 
      13             : namespace v8 {
      14             : namespace internal {
      15             : 
      16             : // This is a special cell used to maintain both the link between a
      17             : // closure and its feedback vector, as well as a way to count the
      18             : // number of closures created for a certain function per native
      19             : // context. There's at most one FeedbackCell for each function in
      20             : // a native context.
      21             : class FeedbackCell : public Struct {
      22             :  public:
      23             :   static int GetInitialInterruptBudget() {
      24     5703729 :     if (FLAG_lazy_feedback_allocation) {
      25           0 :       return FLAG_budget_for_feedback_vector_allocation;
      26             :     }
      27     5703729 :     return FLAG_interrupt_budget;
      28             :   }
      29             : 
      30             :   // [value]: value of the cell.
      31             :   DECL_ACCESSORS(value, HeapObject)
      32             :   DECL_INT32_ACCESSORS(interrupt_budget)
      33             : 
      34             :   DECL_CAST(FeedbackCell)
      35             : 
      36             :   // Dispatched behavior.
      37             :   DECL_PRINTER(FeedbackCell)
      38             :   DECL_VERIFIER(FeedbackCell)
      39             : 
      40             : // Layout description.
      41             : #define FEEDBACK_CELL_FIELDS(V)         \
      42             :   V(kValueOffset, kTaggedSize)          \
      43             :   /* Non-pointer fields */              \
      44             :   V(kInterruptBudgetOffset, kInt32Size) \
      45             :   /* Total size. */                     \
      46             :   V(kUnalignedSize, 0)
      47             : 
      48             :   DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize, FEEDBACK_CELL_FIELDS)
      49             : #undef FEEDBACK_CELL_FIELDS
      50             : 
      51             :   static const int kSize = RoundUp<kObjectAlignment>(int{kUnalignedSize});
      52             : 
      53             :   inline void clear_padding();
      54             : 
      55             :   using BodyDescriptor =
      56             :       FixedBodyDescriptor<kValueOffset, kInterruptBudgetOffset, kSize>;
      57             : 
      58             :   OBJECT_CONSTRUCTORS(FeedbackCell, Struct);
      59             : };
      60             : 
      61             : }  // namespace internal
      62             : }  // namespace v8
      63             : 
      64             : #include "src/objects/object-macros-undef.h"
      65             : 
      66             : #endif  // V8_OBJECTS_FEEDBACK_CELL_H_