Changes error handling for AudioUnitRender on Mac OSX

media/audio/mac/audio_low_latency_input_mac.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/audio/mac/audio_low_latency_input_mac.h"
 
 #include <CoreServices/CoreServices.h>
 
 #include "base/logging.h"
 #include "base/mac/mac_logging.h"
@@ skipping 568 matching lines @@
   // Receive audio from the AUHAL from the output scope of the Audio Unit.
   OSStatus result = AudioUnitRender(audio_input->audio_unit(),
                                     flags,
                                     time_stamp,
                                     bus_number,
                                     number_of_frames,
                                     audio_input->audio_buffer_list());
   if (result) {
     UMA_HISTOGRAM_SPARSE_SLOWLY("Media.AudioInputCbErrorMac", result);
     OSSTATUS_DLOG(ERROR, result) << "AudioUnitRender() failed ";
-    if (result != kAudioUnitErr_TooManyFramesToProcess) {
-      audio_input->HandleError(result);
-    } else {
+    if (result == kAudioUnitErr_TooManyFramesToProcess) {
       DCHECK(!audio_input->last_success_time_.is_null());
       // We delay stopping the stream for kAudioUnitErr_TooManyFramesToProcess
       // since it has been observed that some USB headsets can cause this error
       // but only for a few initial frames at startup and then then the stream
       // returns to a stable state again. See b/19524368 for details.
       // Instead, we measure time since last valid audio frame and call
       // HandleError() only if a too long error sequence is detected. We do
       // this to avoid ending up in a non recoverable bad core audio state.
       base::TimeDelta time_since_last_success =
           base::TimeTicks::Now() - audio_input->last_success_time_;
       if ((time_since_last_success >
            base::TimeDelta::FromSeconds(kMaxErrorTimeoutInSeconds))) {
         DLOG(ERROR) << "Too long sequence of TooManyFramesToProcess errors!";
         audio_input->HandleError(result);
       }
+    } else if (result == kAudioUnitErr_CannotDoInCurrentContext) {
+      // Returned when an audio unit is in a state where it can't perform the
+      // requested action now - but it could later.
+      // TODO(henrika): figure out why we see this error message.
+      DLOG(ERROR) << "kAudioUnitErr_CannotDoInCurrentContext";

[tommi (sloooow) - chröme, 2016/01/21 12:36:12]

maybe LOG(ERROR) for now?  In case this could be useful for in-the-field
troubleshooting.

[tommi (sloooow) - chröme, 2016/01/21 12:42:42]

what about this comment?

[henrika (OOO until Aug 14), 2016/01/21 12:44:13]

Done. Changed some more to LOG as well. To ensure that we can see these logs in
Canary as well.

[henrika (OOO until Aug 14), 2016/01/21 12:53:08]

Done.

+    } else if (result == kAudioUnitErr_NoConnection) {
+      // There is no connection (generally an audio unit is asked to render
+      // but it has not input from which to gather data).
+      // TODO(henrika): figure out why we see this error message.
+      DLOG(ERROR) << "kAudioUnitErr_NoConnection";

[tommi (sloooow) - chröme, 2016/01/21 12:36:12]

I think we should treat this one like a general case.  If the device isn't
connected, it makes sense to report an error and close the stream.  Logging the
error seems useful though.

[tommi (sloooow) - chröme, 2016/01/21 12:42:42]

LOG(ERROR) could be useful for this error as well (or any other error actually).
 What about adding a LOG(ERROR) just before we call HandleError()?

[henrika (OOO until Aug 14), 2016/01/21 12:44:13]

Done.

[henrika (OOO until Aug 14), 2016/01/21 12:53:08]

It is covered above by OSSTATUS_DLOG(ERROR, result) << "AudioUnitRender() failed
";

+    } else {
+      audio_input->HandleError(result);
     }
     return result;
   }
   // Update time of successful call to AudioUnitRender().
   audio_input->last_success_time_ = base::TimeTicks::Now();
 
   // Deliver recorded data to the consumer as a callback.
   return audio_input->Provide(number_of_frames,
                               audio_input->audio_buffer_list(),
                               time_stamp);
@@ skipping 231 matching lines @@
                             manager_->low_latency_input_streams());
   UMA_HISTOGRAM_COUNTS_1000("Media.Audio.NumberOfBasicInputStreamsMac",
                             manager_->basic_input_streams());
   // TODO(henrika): this value will currently always report true. It should be
   // fixed when we understand the problem better.
   UMA_HISTOGRAM_BOOLEAN("Media.Audio.AutomaticGainControlMac",
                         GetAutomaticGainControl());
 }
 
 }  // namespace media