base/profiler/scoped_profile.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5
   6 #ifndef BASE_PROFILER_SCOPED_PROFILE_H_
   7 #define BASE_PROFILER_SCOPED_PROFILE_H_
   8
   9 //------------------------------------------------------------------------------
  10 // ScopedProfile provides basic helper functions for profiling a short
  11 // region of code within a scope.  It is separate from the related ThreadData
  12 // class so that it can be included without much other cruft, and provide the
  13 // macros listed below.
  14
  15 #include "base/base_export.h"
  16 #include "base/location.h"
  17 #include "base/profiler/tracked_time.h"
  18 #include "base/tracked_objects.h"
  19
  20 #define PASTE_LINE_NUMBER_ON_NAME(name, line) name##line
  21
  22 #define LINE_BASED_VARIABLE_NAME_FOR_PROFILING                                 \
  23     PASTE_LINE_NUMBER_ON_NAME(some_profiler_variable_, __LINE__)
  24
  25 // Defines the containing scope as a profiled region. This allows developers to
  26 // profile their code and see results on their about:profiler page, as well as
  27 // on the UMA dashboard.
  28 #define TRACK_RUN_IN_THIS_SCOPED_REGION(dispatch_function_name)            \
  29   ::tracked_objects::ScopedProfile LINE_BASED_VARIABLE_NAME_FOR_PROFILING( \
  30       FROM_HERE_WITH_EXPLICIT_FUNCTION(#dispatch_function_name),           \
  31       ::tracked_objects::ScopedProfile::ENABLED)
  32
  33 namespace tracked_objects {
  34 class Births;
  35
  36 class BASE_EXPORT ScopedProfile {
  37  public:
  38   // Mode of operation. Specifies whether ScopedProfile should be a no-op or
  39   // needs to create and tally a task.
  40   enum Mode {
  41     DISABLED,  // Do nothing.
  42     ENABLED    // Create and tally a task.
  43   };
  44
  45   ScopedProfile(const Location& location, Mode mode);
  46   ~ScopedProfile();
  47
  48  private:
  49   Births* birth_;  // Place in code where tracking started.
  50   TaskStopwatch stopwatch_;
  51
  52   DISALLOW_COPY_AND_ASSIGN(ScopedProfile);
  53 };
  54
  55 }  // namespace tracked_objects
  56
  57 #endif   // BASE_PROFILER_SCOPED_PROFILE_H_