More tracing for audio rendering

content/browser/renderer_host/media/audio_sync_reader.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 "content/browser/renderer_host/media/audio_sync_reader.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/memory/shared_memory.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/stringprintf.h"
+#include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
 #include "content/browser/renderer_host/media/media_stream_manager.h"
 #include "content/public/common/content_switches.h"
 #include "media/base/audio_parameters.h"
 
 using media::AudioBus;
 using media::AudioOutputBuffer;
 
 namespace {
 
@@ skipping 134 matching lines @@
                                                 foreign_socket_.get());
 }
 
 bool AudioSyncReader::PrepareForeignSocket(
     base::ProcessHandle process_handle,
     base::SyncSocket::TransitDescriptor* descriptor) {
   return foreign_socket_->PrepareTransitDescriptor(process_handle, descriptor);
 }
 
 bool AudioSyncReader::WaitUntilDataIsReady() {
+  TRACE_EVENT0("audio", "AudioSyncReader::WaitUntilDataIsReady");
   base::TimeDelta timeout = maximum_wait_time_;
   const base::TimeTicks start_time = base::TimeTicks::Now();
   const base::TimeTicks finish_time = start_time + timeout;
 
   // Check if data is ready and if not, wait a reasonable amount of time for it.
   //
   // Data readiness is achieved via parallel counters, one on the renderer side
   // and one here.  Every time a buffer is requested via UpdatePendingBytes(),
   // |buffer_index_| is incremented.  Subsequently every time the renderer has a
   // buffer ready it increments its counter and sends the counter value over the
@@ skipping 17 matching lines @@
     if (renderer_buffer_index == buffer_index_)
       break;
 
     // Reduce the timeout value as receives succeed, but aren't the right index.
     timeout = finish_time - base::TimeTicks::Now();
   }
 
   // Receive timed out or another error occurred.  Receive can timeout if the
   // renderer is unable to deliver audio data within the allotted time.
   if (!bytes_received || renderer_buffer_index != buffer_index_) {
-    DVLOG(2) << "AudioSyncReader::WaitUntilDataIsReady() timed out.";
+    TRACE_EVENT_INSTANT0("audio", "AudioSyncReader::Read timed out",

[DaleCurtis, 2016/08/19 16:49:00]

Be neat if we could make this show up in a red color or something :)

[o1ka, 2016/08/23 07:16:00]

Would be really cool, but looks like they don't have that.

+                         TRACE_EVENT_SCOPE_THREAD);
 
     base::TimeDelta time_since_start = base::TimeTicks::Now() - start_time;
     UMA_HISTOGRAM_CUSTOM_TIMES("Media.AudioOutputControllerDataNotReady",
                                time_since_start,
                                base::TimeDelta::FromMilliseconds(1),
                                base::TimeDelta::FromMilliseconds(1000),
                                50);
     return false;
   }
 
   return true;
 }
 
 }  // namespace content