components/startup_metric_utils/startup_metric_utils.h

   1 // Copyright 2013 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 #ifndef COMPONENTS_STARTUP_METRIC_UTILS_STARTUP_METRIC_UTILS_H_
   6 #define COMPONENTS_STARTUP_METRIC_UTILS_STARTUP_METRIC_UTILS_H_
   7
   8 #include <string>
   9
  10 #include "base/time/time.h"
  11
  12 // Utility functions to support metric collection for browser startup.
  13
  14 namespace startup_metric_utils {
  15
  16 // Returns true if any UI other than the browser window has been displayed
  17 // so far.  Useful to test if UI has been displayed before the first browser
  18 // window was shown, which would invalidate any surrounding timing metrics.
  19 bool WasNonBrowserUIDisplayed();
  20
  21 // Call this when displaying UI that might potentially delay the appearance
  22 // of the initial browser window on Chrome startup.
  23 //
  24 // Note on usage: This function is idempotent and its overhead is low enough
  25 // in comparison with UI display that it's OK to call it on every
  26 // UI invocation regardless of whether the browser window has already
  27 // been displayed or not.
  28 void SetNonBrowserUIDisplayed();
  29
  30 // Call this as early as possible in the startup process to record a
  31 // timestamp.
  32 void RecordMainEntryPointTime();
  33
  34 // Call this when the executable is loaded and main() is entered. Can be
  35 // different from |RecordMainEntryPointTime| when the startup process is
  36 // contained in a separate dll, such as with chrome.exe / chrome.dll on Windows.
  37 void RecordExeMainEntryTime();
  38
  39 #if defined(OS_ANDROID)
  40 // On Android the entry point time is the time at which the Java code starts.
  41 // This is recorded on the Java side, and then passed to the C++ side once the
  42 // C++ library is loaded and running.
  43 void RecordSavedMainEntryPointTime(const base::Time& entry_point_time);
  44 #endif // OS_ANDROID
  45
  46 // Called just before the message loop is about to start. Entry point to record
  47 // startup stats.
  48 // |is_first_run| - is the current launch part of a first run.
  49 void OnBrowserStartupComplete(bool is_first_run);
  50
  51 // Called when the initial page load has finished in order to record startup
  52 // stats.
  53 void OnInitialPageLoadComplete();
  54
  55 // Returns the time of main entry recorded from RecordMainEntryPointTime.
  56 // Returns NULL if that method has not yet been called.
  57 // This method is expected to be called from the UI thread.
  58 const base::Time* MainEntryPointTime();
  59
  60 // Scoper that records the time period before it's destructed in a histogram
  61 // with the given name. The histogram is only recorded for slow chrome startups.
  62 // Useful for trying to figure out what parts of Chrome cause slow startup.
  63 class ScopedSlowStartupUMA {
  64  public:
  65   explicit ScopedSlowStartupUMA(const std::string& histogram_name)
  66       : start_time_(base::TimeTicks::Now()),
  67         histogram_name_(histogram_name) {}
  68
  69   ~ScopedSlowStartupUMA();
  70
  71  private:
  72   const base::TimeTicks start_time_;
  73   const std::string histogram_name_;
  74
  75   DISALLOW_COPY_AND_ASSIGN(ScopedSlowStartupUMA);
  76 };
  77
  78 }  // namespace startup_metric_utils
  79
  80 #endif  // COMPONENTS_STARTUP_METRIC_UTILS_STARTUP_METRIC_UTILS_H_