Report approximated duration in milliseconds for profile nodes.

src/profile-generator.h

 // Copyright 2010 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 52 matching lines @@
   const char* name_;
   const char* resource_name_;
   int line_number_;
 
   static unsigned next_call_uid_;
 
   DISALLOW_COPY_AND_ASSIGN(CodeEntry);
 };
 
 
+class ProfileTree;
+
 class ProfileNode {
  public:
-  INLINE(explicit ProfileNode(CodeEntry* entry));
+  INLINE(ProfileNode(ProfileTree* tree, CodeEntry* entry));
 
   ProfileNode* FindChild(CodeEntry* entry);
   ProfileNode* FindOrAddChild(CodeEntry* entry);
   INLINE(void IncrementSelfTicks()) { ++self_ticks_; }
   INLINE(void IncreaseTotalTicks(unsigned amount)) { total_ticks_ += amount; }
 
   INLINE(CodeEntry* entry() const) { return entry_; }
+  INLINE(unsigned self_ticks() const) { return self_ticks_; }
   INLINE(unsigned total_ticks() const) { return total_ticks_; }
-  INLINE(unsigned self_ticks() const) { return self_ticks_; }
   INLINE(const List<ProfileNode*>* children() const) { return &children_list_; }
+  double GetSelfMillis() const;
+  double GetTotalMillis() const;
 
   void Print(int indent);
 
  private:
   INLINE(static bool CodeEntriesMatch(void* entry1, void* entry2)) {
     return entry1 == entry2;
   }
 
   INLINE(static uint32_t CodeEntryHash(CodeEntry* entry)) {
     return static_cast<int32_t>(reinterpret_cast<intptr_t>(entry));
   }
 
+  ProfileTree* tree_;
   CodeEntry* entry_;
   unsigned total_ticks_;
   unsigned self_ticks_;
   // CodeEntry* -> ProfileNode*
   HashMap children_;
   List<ProfileNode*> children_list_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileNode);
 };
 
 
 class ProfileTree {
  public:
   ProfileTree();
   ~ProfileTree();
 
   void AddPathFromEnd(const Vector<CodeEntry*>& path);
   void AddPathFromStart(const Vector<CodeEntry*>& path);
   void CalculateTotalTicks();
 
+  double TicksToMillis(unsigned ticks) const {
+    return ticks * ms_to_ticks_scale_;
+  }
   ProfileNode* root() const { return root_; }
+  void SetTickRatePerMs(double ticks_per_ms);
 
   void ShortPrint();
   void Print() {
     root_->Print(0);
   }
 
  private:
   template <typename Callback>
-  void TraverseBreadthFirstPostOrder(Callback* callback);
+  void TraverseDepthFirstPostOrder(Callback* callback);
 
   CodeEntry root_entry_;
   ProfileNode* root_;
+  double ms_to_ticks_scale_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileTree);
 };
 
 
 class CpuProfile {
  public:
   CpuProfile(const char* title, unsigned uid)
       : title_(title), uid_(uid) { }
 
   // Add pc -> ... -> main() call path to the profile.
   void AddPath(const Vector<CodeEntry*>& path);
   void CalculateTotalTicks();
+  void SetActualSamplingRate(double actual_sampling_rate);
 
   INLINE(const char* title() const) { return title_; }
   INLINE(unsigned uid() const) { return uid_; }
   INLINE(const ProfileTree* top_down() const) { return &top_down_; }
   INLINE(const ProfileTree* bottom_up() const) { return &bottom_up_; }
 
+  void UpdateTicksScale();
+
   void ShortPrint();
   void Print();
 
  private:
   const char* title_;
   unsigned uid_;
   ProfileTree top_down_;
   ProfileTree bottom_up_;
 
   DISALLOW_COPY_AND_ASSIGN(CpuProfile);
@@ skipping 41 matching lines @@
 };
 
 
 class CpuProfilesCollection {
  public:
   CpuProfilesCollection();
   ~CpuProfilesCollection();
 
   bool StartProfiling(const char* title, unsigned uid);
   bool StartProfiling(String* title, unsigned uid);
-  CpuProfile* StopProfiling(const char* title);
-  CpuProfile* StopProfiling(String* title);
+  CpuProfile* StopProfiling(const char* title, double actual_sampling_rate);
+  CpuProfile* StopProfiling(String* title, double actual_sampling_rate);
   INLINE(List<CpuProfile*>* profiles()) { return &profiles_; }
   CpuProfile* GetProfile(unsigned uid);
   inline bool is_last_profile();
 
   CodeEntry* NewCodeEntry(Logger::LogEventsAndTags tag,
                           String* name, String* resource_name, int line_number);
   CodeEntry* NewCodeEntry(Logger::LogEventsAndTags tag, const char* name);
   CodeEntry* NewCodeEntry(Logger::LogEventsAndTags tag,
                           const char* name_prefix, String* name);
   CodeEntry* NewCodeEntry(Logger::LogEventsAndTags tag, int args_count);
@@ skipping 26 matching lines @@
   HashMap profiles_uids_;
 
   // Accessed by VM thread and profile generator thread.
   List<CpuProfile*> current_profiles_;
   Semaphore* current_profiles_semaphore_;
 
   DISALLOW_COPY_AND_ASSIGN(CpuProfilesCollection);
 };
 
 
+class SampleRateCalculator {
+ public:
+  SampleRateCalculator()
+      : result_(Logger::kSamplingIntervalMs * kResultScale),
+        ticks_per_ms_(Logger::kSamplingIntervalMs),
+        measurements_count_(0),
+        wall_time_query_countdown_(1) {
+  }
+
+  double ticks_per_ms() {
+    return result_ / static_cast<double>(kResultScale);
+  }
+  void Tick();
+  void UpdateMeasurements(double current_time);
+
+  // Instead of querying current wall time each tick,
+  // we use this constant to control query intervals.
+  static const unsigned kWallTimeQueryIntervalMs = 100;
+
+ private:
+  // As the result needs to be accessed from a different thread, we
+  // use type that guarantees atomic writes to memory.  There should
+  // be <= 1000 ticks per second, thus storing a value of a 10 ** 5
+  // order should provide enough precision while keeping away from a
+  // potential overflow.
+  static const int kResultScale = 100000;
+
+  AtomicWord result_;
+  // All other fields are accessed only from the sampler thread.
+  double ticks_per_ms_;
+  unsigned measurements_count_;
+  unsigned wall_time_query_countdown_;
+  double last_wall_time_;
+};
+
+
 class ProfileGenerator {
  public:
   explicit ProfileGenerator(CpuProfilesCollection* profiles);
 
   INLINE(CodeEntry* NewCodeEntry(Logger::LogEventsAndTags tag,
                                  String* name,
                                  String* resource_name,
                                  int line_number)) {
     return profiles_->NewCodeEntry(tag, name, resource_name, line_number);
   }
@@ skipping 11 matching lines @@
 
   INLINE(CodeEntry* NewCodeEntry(Logger::LogEventsAndTags tag,
                                  int args_count)) {
     return profiles_->NewCodeEntry(tag, args_count);
   }
 
   void RecordTickSample(const TickSample& sample);
 
   INLINE(CodeMap* code_map()) { return &code_map_; }
 
+  INLINE(void Tick()) { sample_rate_calc_.Tick(); }
+  INLINE(double actual_sampling_rate()) {
+    return sample_rate_calc_.ticks_per_ms();
+  }
+
   static const char* kAnonymousFunctionName;
   static const char* kProgramEntryName;
   static const char* kGarbageCollectorEntryName;
 
  private:
   INLINE(CodeEntry* EntryForVMState(StateTag tag));
 
   CpuProfilesCollection* profiles_;
   CodeMap code_map_;
   CodeEntry* program_entry_;
   CodeEntry* gc_entry_;
+  SampleRateCalculator sample_rate_calc_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileGenerator);
 };
 
 } }  // namespace v8::internal
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 #endif  // V8_PROFILE_GENERATOR_H_