| // Copyright 2020 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_PROFILER_PROFILER_STATS_H_ | 
 | #define V8_PROFILER_PROFILER_STATS_H_ | 
 |  | 
 | #include <atomic> | 
 |  | 
 | namespace v8 { | 
 | namespace internal { | 
 |  | 
 | // Stats are used to diagnose the reasons for dropped or unnattributed frames. | 
 | class ProfilerStats { | 
 |  public: | 
 |   enum Reason { | 
 |     // Reasons we fail to record a TickSample. | 
 |     kTickBufferFull, | 
 |     kIsolateNotLocked, | 
 |     // These all generate a TickSample. | 
 |     kSimulatorFillRegistersFailed, | 
 |     kNoFrameRegion, | 
 |     kInCallOrApply, | 
 |     kNoSymbolizedFrames, | 
 |     kNullPC, | 
 |  | 
 |     kNumberOfReasons, | 
 |   }; | 
 |  | 
 |   static ProfilerStats* Instance() { | 
 |     static ProfilerStats stats; | 
 |     return &stats; | 
 |   } | 
 |  | 
 |   void AddReason(Reason reason); | 
 |   void Clear(); | 
 |   void Print() const; | 
 |  | 
 |  private: | 
 |   ProfilerStats() = default; | 
 |   static const char* ReasonToString(Reason reason); | 
 |  | 
 |   std::atomic_int counts_[Reason::kNumberOfReasons] = {}; | 
 | }; | 
 |  | 
 | }  // namespace internal | 
 | }  // namespace v8 | 
 |  | 
 | #endif  // V8_PROFILER_PROFILER_STATS_H_ |