Support profiling based on linux kernel performance events.

src/log-utils.h

 // Copyright 2006-2009 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 134 matching lines @@
   // Whether logging is stopped (e.g. due to insufficient resources).
   static bool is_stopped_;
 
   // When logging is active, either output_handle_ or output_buffer_ is used
   // to store a pointer to log destination. If logging was opened via OpenStdout
   // or OpenFile, then output_handle_ is used. If logging was opened
   // via OpenMemoryBuffer, then output_buffer_ is used.
   // mutex_ should be acquired before using output_handle_ or output_buffer_.
   static FILE* output_handle_;
 
+  // Used when low-level profiling is active to save code object contents.
+  static FILE* output_code_handle_;
+
   static LogDynamicBuffer* output_buffer_;
 
   // Size of dynamic buffer block (and dynamic buffer initial size).
   static const int kDynamicBufferBlockSize = 65536;
 
   // Maximum size of dynamic buffer.
   static const int kMaxDynamicBufferSize = 50 * 1024 * 1024;
 
   // Message to "seal" dynamic buffer with.
   static const char* kDynamicBufferSeal;
 
   // mutex_ is a Mutex used for enforcing exclusive
   // access to the formatting buffer and the log file or log memory buffer.
   static Mutex* mutex_;
 
   // Buffer used for formatting log messages. This is a singleton buffer and
   // mutex_ should be acquired before using it.
   static char* message_buffer_;
 
+  friend class Logger;
   friend class LogMessageBuilder;
   friend class LogRecordCompressor;
 };
 
 
 // An utility class for performing backward reference compression
 // of string ends. It operates using a window of previous strings.
 class LogRecordCompressor {
  public:
   // 'window_size' is the size of backward lookup window.
@@ skipping 97 matching lines @@
 
   ScopedLock sl;
   int pos_;
 };
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal
 
 #endif  // V8_LOG_UTILS_H_