Live counters in d8

src/d8.h

 // Copyright 2008 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 24 matching lines @@
 
 #include "v8.h"
 
 
 namespace v8 {
 
 
 namespace i = v8::internal;
 
 
+// A single counter in a counter collection.
 class Counter {
  public:
-  explicit Counter(const char* name)
-    : name_(name), value_(0) { }
-  int* GetValuePtr() { return &value_; }
-  const char* name() { return name_; }
-  int value() { return value_; }
+  static const int kMaxNameSize = 64;
+  int32_t* Bind(const char* name);
+  int32_t* ptr() { return &counter_; }
+  int32_t value() { return counter_; }
  private:
-  const char* name_;
-  int value_;
+  int32_t counter_;
+  uint8_t name_[kMaxNameSize];
 };
 
 
+// A set of counters and associated information.  An instance of this
+// class is stored directly in the memory-mapped counters file if
+// the --map-counters options is used
+class CounterCollection {
+ public:
+  CounterCollection();
+  Counter* GetNextCounter();
+ private:
+  static const unsigned kMaxCounters = 256;
+  uint32_t magic_number_;
+  uint32_t max_counters_;
+  uint32_t max_name_size_;
+  uint32_t counters_in_use_;
+  Counter counters_[kMaxCounters];
+};
+
+
 class Shell: public i::AllStatic {
  public:
   static bool ExecuteString(Handle<String> source,
                             Handle<Value> name,
                             bool print_result,
                             bool report_exceptions);
   static void ReportException(TryCatch* try_catch);
   static void Initialize();
   static void OnExit();
   static int* LookupCounter(const char* name);
+  static void MapCounters(const char* name);
   static Handle<String> ReadFile(const char* name);
   static void RunShell();
   static int Main(int argc, char* argv[]);
   static Handle<Array> GetCompletions(Handle<String> text,
                                       Handle<String> full);
 
   static Handle<Value> Print(const Arguments& args);
   static Handle<Value> Quit(const Arguments& args);
   static Handle<Value> Version(const Arguments& args);
   static Handle<Value> Load(const Arguments& args);
 
   static const char* kHistoryFileName;
   static const char* kPrompt;
  private:
   static Persistent<Context> utility_context_;
   static Persistent<Context> evaluation_context_;
   typedef std::map<const char*, Counter*> CounterMap;
   static CounterMap counter_map_;
+  // We statically allocate a set of local counters to be used if we
+  // don't want to store the stats in a memory-mapped file
+  static CounterCollection local_counters_;
+  static CounterCollection* counters_;
+  static i::OS::MemoryMappedFile* counters_file_;
 };
 
 
 class LineEditor {
  public:
   enum Type { DUMB = 0, READLINE = 1 };
   LineEditor(Type type, const char* name);
   virtual ~LineEditor() { }
 
   virtual i::SmartPointer<char> Prompt(const char* prompt) = 0;
   virtual bool Open() { return true; }
   virtual bool Close() { return true; }
   virtual void AddHistory(const char* str) { }
 
   const char* name() { return name_; }
   static LineEditor* Get();
  private:
   Type type_;
   const char* name_;
   LineEditor* next_;
   static LineEditor* first_;
 };
 
 
 }  // namespace v8
 
 
 #endif  // V8_D8_H_