Extend CPU profiler with mapping ticks to source lines

src/profile-generator.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_PROFILE_GENERATOR_H_
 #define V8_PROFILE_GENERATOR_H_
 
+#include <map>
 #include "include/v8-profiler.h"
 #include "src/allocation.h"
 #include "src/hashmap.h"
 
 namespace v8 {
 namespace internal {
 
 struct OffsetRange;
 
 // Provides a storage of strings allocated in C++ heap, to hold them
@@ skipping 19 matching lines @@
   const char* AddOrDisposeString(char* str, int len);
   HashMap::Entry* GetEntry(const char* str, int len);
 
   uint32_t hash_seed_;
   HashMap names_;
 
   DISALLOW_COPY_AND_ASSIGN(StringsStorage);
 };
 
 
+// Provides a mapping from the offsets within generated code to
+// the source line.
+class JITLineInfoTable : public Malloced {
+ public:
+  JITLineInfoTable() {}
+  ~JITLineInfoTable() {}
+
+  void SetPosition(int pc_offset, int line) {
+    DCHECK(pc_offset >= 0);
+    DCHECK(line > 0);  // The 1-based number of the source line.
+    pc_offset_map_.insert(std::make_pair(pc_offset, line));

[alph, 2014/08/15 12:10:47]

a possible optimization: you don't need to bloat it with a new entry if
lower_bound for the pc_offset does already return line.

[Denis Pravdin, 2014/09/01 10:44:38]

SetPosition is called during code generation. GetSourceLineNumber is called
after the code is generated and line info table is built. Could you please
clarify what kind of optimization are your talking about?

On 2014/08/15 12:10:47, alph wrote:

[Weiliang, 2014/09/03 02:29:48]

Does it mean below?
    if (GetSourceLineNumber(pc_offset) ==
        v8::CpuProfileNode::kNoLineNumberInfo) {
      pc_offset_map_.insert(std::make_pair(pc_offset, line));
    }

[alph, 2014/09/09 14:47:34]

I meant:
if (GetSourceLineNumber(pc_offset) != line) {
  pc_offset_map_.insert(std::make_pair(pc_offset, line));
}

+  }
+
+  int GetSourceLineNumber(int pc_offset) const {
+    PcOffsetMap::const_iterator it = pc_offset_map_.lower_bound(pc_offset);
+    if (it == pc_offset_map_.end()) {
+      return v8::CpuProfileNode::kNoLineNumberInfo;
+    }
+    return it->second;
+  }
+
+  bool Empty() const { return pc_offset_map_.empty(); }
+
+ private:
+  // pc_offset -> source line
+  typedef std::map<int, int> PcOffsetMap;
+  PcOffsetMap pc_offset_map_;
+  DISALLOW_COPY_AND_ASSIGN(JITLineInfoTable);
+};
+
 class CodeEntry {
  public:
   // CodeEntry doesn't own name strings, just references them.
   inline CodeEntry(Logger::LogEventsAndTags tag,
                    const char* name,
                    const char* name_prefix = CodeEntry::kEmptyNamePrefix,
                    const char* resource_name = CodeEntry::kEmptyResourceName,
                    int line_number = v8::CpuProfileNode::kNoLineNumberInfo,
-                   int column_number = v8::CpuProfileNode::kNoColumnNumberInfo);
+                   int column_number = v8::CpuProfileNode::kNoColumnNumberInfo,
+                   JITLineInfoTable* line_info = NULL);
   ~CodeEntry();
 
   bool is_js_function() const { return is_js_function_tag(tag_); }
   const char* name_prefix() const { return name_prefix_; }
   bool has_name_prefix() const { return name_prefix_[0] != '\0'; }
   const char* name() const { return name_; }
   const char* resource_name() const { return resource_name_; }
   int line_number() const { return line_number_; }
   int column_number() const { return column_number_; }
+  const JITLineInfoTable* line_info() const { return line_info_; }
   void set_shared_id(int shared_id) { shared_id_ = shared_id; }
   int script_id() const { return script_id_; }
   void set_script_id(int script_id) { script_id_ = script_id; }
   void set_bailout_reason(const char* bailout_reason) {
     bailout_reason_ = bailout_reason;
   }
   const char* bailout_reason() const { return bailout_reason_; }
 
   static inline bool is_js_function_tag(Logger::LogEventsAndTags tag);
 
   List<OffsetRange>* no_frame_ranges() const { return no_frame_ranges_; }
   void set_no_frame_ranges(List<OffsetRange>* ranges) {
     no_frame_ranges_ = ranges;
   }
 
   void SetBuiltinId(Builtins::Name id);
   Builtins::Name builtin_id() const { return builtin_id_; }
 
   uint32_t GetCallUid() const;
   bool IsSameAs(CodeEntry* entry) const;
 
+  int GetSourceLine(int pc_offset) const;
+
   static const char* const kEmptyNamePrefix;
   static const char* const kEmptyResourceName;
   static const char* const kEmptyBailoutReason;
 
  private:
   Logger::LogEventsAndTags tag_ : 8;
   Builtins::Name builtin_id_ : 8;
   const char* name_prefix_;
   const char* name_;
   const char* resource_name_;
   int line_number_;
   int column_number_;
   int shared_id_;
   int script_id_;
   List<OffsetRange>* no_frame_ranges_;
   const char* bailout_reason_;
+  JITLineInfoTable* line_info_;
 
   DISALLOW_COPY_AND_ASSIGN(CodeEntry);
 };
 
 
 class ProfileTree;
 
 class ProfileNode {
  public:
   inline ProfileNode(ProfileTree* tree, CodeEntry* entry);
 
   ProfileNode* FindChild(CodeEntry* entry);
   ProfileNode* FindOrAddChild(CodeEntry* entry);
   void IncrementSelfTicks() { ++self_ticks_; }
   void IncreaseSelfTicks(unsigned amount) { self_ticks_ += amount; }
+  void IncrementLineTicks(int src_line);
 
   CodeEntry* entry() const { return entry_; }
   unsigned self_ticks() const { return self_ticks_; }
   const List<ProfileNode*>* children() const { return &children_list_; }
   unsigned id() const { return id_; }
+  unsigned int GetHitLineCount() const { return line_ticks_.occupancy(); }
+  bool GetLineTicks(v8::CpuProfileNode::LineTick* entries,
+                    unsigned int length) const;
 
   void Print(int indent);
 
  private:
   static bool CodeEntriesMatch(void* entry1, void* entry2) {
     return reinterpret_cast<CodeEntry*>(entry1)->IsSameAs(
         reinterpret_cast<CodeEntry*>(entry2));
   }
 
   static uint32_t CodeEntryHash(CodeEntry* entry) {
     return entry->GetCallUid();
   }
 
   ProfileTree* tree_;
   CodeEntry* entry_;
   unsigned self_ticks_;
   // Mapping from CodeEntry* to ProfileNode*
   HashMap children_;
   List<ProfileNode*> children_list_;
   unsigned id_;
+  HashMap line_ticks_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileNode);
 };
 
 
 class ProfileTree {
  public:
   ProfileTree();
   ~ProfileTree();
 
-  ProfileNode* AddPathFromEnd(const Vector<CodeEntry*>& path);
-  void AddPathFromStart(const Vector<CodeEntry*>& path);
+  ProfileNode* AddPathFromEnd(
+    const Vector<CodeEntry*>& path,
+    int src_line = v8::CpuProfileNode::kNoLineNumberInfo);
+  void AddPathFromStart(const Vector<CodeEntry*>& path,
+                        int src_line = v8::CpuProfileNode::kNoLineNumberInfo);
   ProfileNode* root() const { return root_; }
   unsigned next_node_id() { return next_node_id_++; }
 
   void Print() {
     root_->Print(0);
   }
 
  private:
   template <typename Callback>
   void TraverseDepthFirst(Callback* callback);
 
   CodeEntry root_entry_;
   unsigned next_node_id_;
   ProfileNode* root_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileTree);
 };
 
 
 class CpuProfile {
  public:
   CpuProfile(const char* title, bool record_samples);
 
   // Add pc -> ... -> main() call path to the profile.
-  void AddPath(base::TimeTicks timestamp, const Vector<CodeEntry*>& path);
+  void AddPath(base::TimeTicks timestamp,
+               const Vector<CodeEntry*>& path,
+               int src_line);
   void CalculateTotalTicksAndSamplingRate();
 
   const char* title() const { return title_; }
   const ProfileTree* top_down() const { return &top_down_; }
 
   int samples_count() const { return samples_.length(); }
   ProfileNode* sample(int index) const { return samples_.at(index); }
   base::TimeTicks sample_timestamp(int index) const {
     return timestamps_.at(index);
   }
@@ skipping 86 matching lines @@
   }
   bool IsLastProfile(const char* title);
   void RemoveProfile(CpuProfile* profile);
 
   CodeEntry* NewCodeEntry(
       Logger::LogEventsAndTags tag,
       const char* name,
       const char* name_prefix = CodeEntry::kEmptyNamePrefix,
       const char* resource_name = CodeEntry::kEmptyResourceName,
       int line_number = v8::CpuProfileNode::kNoLineNumberInfo,
-      int column_number = v8::CpuProfileNode::kNoColumnNumberInfo);
+      int column_number = v8::CpuProfileNode::kNoColumnNumberInfo,
+      JITLineInfoTable* line_info = NULL);
 
   // Called from profile generator thread.
-  void AddPathToCurrentProfiles(
-      base::TimeTicks timestamp, const Vector<CodeEntry*>& path);
+  void AddPathToCurrentProfiles(base::TimeTicks timestamp,
+                                const Vector<CodeEntry*>& path,
+                                int src_line);
 
   // Limits the number of profiles that can be simultaneously collected.
   static const int kMaxSimultaneousProfiles = 100;
 
  private:
   StringsStorage function_and_resource_names_;
   List<CodeEntry*> code_entries_;
   List<CpuProfile*> finished_profiles_;
 
   // Accessed by VM thread and profile generator thread.
@@ skipping 29 matching lines @@
   CodeEntry* gc_entry_;
   CodeEntry* unresolved_entry_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileGenerator);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_PROFILE_GENERATOR_H_