First step in refactoring the logging system to allow the logging messages to...

src/log.h

 // Copyright 2006-2008 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 51 matching lines @@
 //
 // --prof
 // Collect statistical profiling information (ticks), default is off.  The
 // tick profiler requires code events, so --prof implies --log-code.
 
 // Forward declarations.
 class Ticker;
 class Profiler;
 class Semaphore;
 class SlidingStateWindow;
+class LogMessageBuilder;
 
 #undef LOG
 #ifdef ENABLE_LOGGING_AND_PROFILING
 #define LOG(Call)                           \
   do {                                      \
     if (v8::internal::Logger::is_enabled()) \
       v8::internal::Logger::Call;           \
   } while (false)
 #else
 #define LOG(Call) ((void) 0)
@@ skipping 138 matching lines @@
   static void LogString(Handle<String> str, bool show_impl_info);
 
   // Emits a profiler tick event. Used by the profiler thread.
   static void TickEvent(TickSample* sample, bool overflow);
 
   static void ApiEvent(const char* name, ...);
 
   // Logs a StringEvent regardless of whether FLAG_log is true.
   static void UncheckedStringEvent(const char* name, const char* value);
 
-  // When logging is active, logfile_ refers the file
-  // events are written to.
+  // Size of buffer used for formatting log messages.
+  static const int kMessageBufferSize = 256;
+
+  // Buffer used for formatting log messages. This is a singleton buffer and
+  // mutex_ should be acquired before using it.
+  static char* message_buffer_;
+
+  // When logging is active, logfile_ refers the file events are written to.
+  // mutex_ should be acquired before using logfile_.
   static FILE* logfile_;
 
   // The sampler used by the profiler and the sliding state window.
   static Ticker* ticker_;
 
   // When the statistical profile is active, profiler_
   // points to a Profiler, that handles collection
   // of samples.
   static Profiler* profiler_;
 
   // mutex_ is a Mutex used for enforcing exclusive
-  // access to the log file.
+  // access to the formatting buffer and the log file.
   static Mutex* mutex_;
 
   // A stack of VM states.
   static VMState* current_state_;
 
   // SlidingStateWindow instance keeping a sliding window of the most
   // recent VM states.
   static SlidingStateWindow* sliding_state_window_;
 
   // Internal implementation classes with access to
   // private members.
+  friend class LogMessageBuilder;
   friend class EventLog;
   friend class TimeLog;
   friend class Profiler;
   friend class SlidingStateWindow;
   friend class VMState;
 #endif
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LOG_H_