Adding time profiling support to AudioFrame

webrtc/modules/include/module_common_types.h

Index: webrtc/modules/include/module_common_types.h
diff --git a/webrtc/modules/include/module_common_types.h b/webrtc/modules/include/module_common_types.h
index a3ac2bbc56adb2cd13960d71431eb06fd82b4c96..b4305b79ef470702f35fc8909acc4a154d903309 100644
--- a/webrtc/modules/include/module_common_types.h
+++ b/webrtc/modules/include/module_common_types.h
@@ -26,6 +26,7 @@
 #include "webrtc/rtc_base/constructormagic.h"
 #include "webrtc/rtc_base/deprecation.h"
 #include "webrtc/rtc_base/safe_conversions.h"
+#include "webrtc/rtc_base/timeutils.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
@@ -336,6 +337,16 @@ class AudioFrame {
 
   void CopyFrom(const AudioFrame& src);
 
+  // Sets a wall-time clock timestamp in milliseconds to be used for profiling
+  // of time between two points in the audio chain.
+  // Example:
+  //   t0: UpdateProfileTime()
+  //   t1: TimeSinceLastProfile() => t1 - t0 [msec]
+  void UpdateProfileTime();

[hlundin-webrtc, 2017/09/14 13:34:33]

Suggest UpdateProfileTimestamp to match variable name.

[henrika_webrtc, 2017/09/15 13:33:57]

Done.

+  // Returns the time difference between now and when UpdateProfileTime() was
+  // last called. Returns -1 if UpdateProfileTime() has not yet been called.
+  int64_t TimeSinceLastProfile() const;

[hlundin-webrtc, 2017/09/14 13:34:34]

Suggest ElapsedProfileTimeMs().

[henrika_webrtc, 2017/09/15 13:33:57]

Done.

+
   // data() returns a zeroed static buffer if the frame is muted.
   // mutable_frame() always returns a non-static buffer; the first call to
   // mutable_frame() zeros the non-static buffer and marks the frame unmuted.
@@ -368,6 +379,12 @@ class AudioFrame {
   size_t num_channels_ = 0;
   SpeechType speech_type_ = kUndefined;
   VADActivity vad_activity_ = kVadUnknown;
+  // Monotonically increasing timestamp intended for profiling of audio frames.
+  // Typically used for measuring elapsed time between two different points in
+  // the audio path. No lock is used to save resources and we are thread safe
+  // by design. Also, rtc::Optional is not used since it will cause a "complex

[hlundin-webrtc, 2017/09/14 13:45:39]

+kwiberg@, would you consider this reason enough to create a corresponding .cc
file, or is it too much work?

[henrika_webrtc, 2017/09/15 13:33:57]

IMHO, adding a cc-file for this functionality only feels like overkill.

[kwiberg-webrtc, 2017/09/15 17:52:29]

If build targets are set up properly (as they should be, and almost always are
nowadays), adding a .cc file is very little work. So if using Optional is the
right thing to do, don't avoid it just because you'll need a .cc file.

+  // class/struct needs an explicit out-of-line destructor" build error.
+  int64_t profile_time_stamp_ms_ = 0;

[hlundin-webrtc, 2017/09/14 13:34:33]

The convention in this file is to write timestamp as one word. Thus,
profile_timestamp_ms_.

[henrika_webrtc, 2017/09/15 13:33:57]

Done.

 
  private:
   // A permamently zeroed out buffer to represent muted frames. This is a
@@ -407,6 +424,7 @@ inline void AudioFrame::ResetWithoutMuting() {
   num_channels_ = 0;
   speech_type_ = kUndefined;
   vad_activity_ = kVadUnknown;
+  profile_time_stamp_ms_ = 0;
 }
 
 inline void AudioFrame::UpdateFrame(int id,
@@ -457,6 +475,20 @@ inline void AudioFrame::CopyFrom(const AudioFrame& src) {
   }
 }
 
+inline void AudioFrame::UpdateProfileTime() {
+  {

[hlundin-webrtc, 2017/09/14 13:34:33]

Why the extra braces?

[henrika_webrtc, 2017/09/15 13:33:57]

My bad

+    profile_time_stamp_ms_ = rtc::TimeMillis()  ;

[hlundin-webrtc, 2017/09/14 13:34:33]

Delete space before ;

[henrika_webrtc, 2017/09/15 13:33:57]

Done.

+  }
+}
+
+inline int64_t AudioFrame::TimeSinceLastProfile() const {
+  if (profile_time_stamp_ms_ == 0) {
+    // Profiling has not been activated.
+    return -1;
+  }
+  return rtc::TimeSince(profile_time_stamp_ms_);
+}
+
 inline const int16_t* AudioFrame::data() const {
   return muted_ ? empty_data() : data_;
 }