Attempt to reduce performance penalty for logging and profiling

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 10 matching lines @@
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_LOG_H_
 #define V8_LOG_H_
 
+#include "platform.h"
+#include "log-utils.h"
+
 namespace v8 {
 namespace internal {
 
 // Logger is used for collecting logging information from V8 during
 // execution. The result is dumped to a file.
 //
 // Available command line flags:
 //
 //  --log
 // Minimal logging (no API, code, or GC sample events), default is off.
@@ skipping 29 matching lines @@
 class Profiler;
 class Semaphore;
 class SlidingStateWindow;
 class LogMessageBuilder;
 class CompressionHelper;
 
 #undef LOG
 #ifdef ENABLE_LOGGING_AND_PROFILING
 #define LOG(Call)                           \
   do {                                      \
-    if (v8::internal::Logger::IsEnabled()) \
+    if (v8::internal::Logger::is_logging()) \
       v8::internal::Logger::Call;           \
   } while (false)
 #else
 #define LOG(Call) ((void) 0)
 #endif
 
 
 class VMState BASE_EMBEDDED {
 #ifdef ENABLE_LOGGING_AND_PROFILING
  public:
-  explicit VMState(StateTag state);
-  ~VMState();
+  inline explicit VMState(StateTag state);
+  inline ~VMState();
 
   StateTag state() { return state_; }
 
  private:
+  bool disabled_;
   StateTag state_;
   VMState* previous_;
 #else
  public:
   explicit VMState(StateTag state) {}
 #endif
 };
 
 
 #define LOG_EVENTS_AND_TAGS_LIST(V) \
@@ skipping 122 matching lines @@
   static void RegExpCompileEvent(Handle<JSRegExp> regexp, bool in_cache);
 
   // Log an event reported from generated code
   static void LogRuntime(Vector<const char> format, JSArray* args);
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
   static StateTag state() {
     return current_state_ ? current_state_->state() : OTHER;
   }
 
-  static bool IsEnabled();
+  static bool is_logging() {
+    return is_logging_;
+  }
 
   // Pause/Resume collection of profiling data.
   // When data collection is paused, Tick events are discarded until
   // data collection is Resumed.
   static bool IsProfilerPaused();
   static void PauseProfiler();
   static void ResumeProfiler();
 
   // If logging is performed into a memory buffer, allows to
   // retrieve previously written messages. See v8.h.
@@ skipping 60 matching lines @@
   // Internal implementation classes with access to
   // private members.
   friend class CompressionHelper;
   friend class EventLog;
   friend class TimeLog;
   friend class Profiler;
   friend class SlidingStateWindow;
   friend class VMState;
 
   friend class LoggerTestHelper;
+
+  static bool is_logging_;
 #else
-  static bool is_enabled() { return false; }
+  static bool is_logging() { return false; }
 #endif
 };
 
 
 // Class that extracts stack trace, used for profiling.
 class StackTracer : public AllStatic {
  public:
   static void Trace(TickSample* sample);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LOG_H_