commit 82aaf94a5b18939e4d790bbc752031f3070704a3
author Glenn Kasten <gkasten@google.com> Wed Jul 17 16:05:07 2013 -0700
committer Glenn Kasten <gkasten@google.com> Wed Jul 31 09:15:00 2013 -0700
tree 4e39e32d0ccde726548afcbd81e253d5e316b295
parent b08ab81bab9e8cd2e3a7fff02725a387070fd078

Report underruns for fast tracks also

This fixes a regression that was introduced earlier
by commit 9f80dd223d83d9bb9077fb6baee056cee4eaf7e5
called "New control block for AudioTrack and AudioRecord".
That commit broke underrun reporting for fast tracks.

Also remove Track::mUnderrunCount, which counted the number of underrun
events, and was only used by dumpsys media.audio_flinger.

Now dumpsys media.audio_flinger reports the number of underrun frames,

Isolated underrun-related control block accesses via the proxy, so that
the server is not directly poking around in the control block.

The new proxy APIs are AudioTrackServerProxy::getUnderrunFrames() and
AudioTrackServerProxy::tallyUnderrunFrames().  getUnderrunFrames() returns
a rolling counter for streaming tracks, or zero for static buffer tracks
which never underrun, but do a kind of 'pause' at end of buffer.
tallyUnderrunFrames() increments the counter by a specified number of frames.

Change-Id: Ib31fd73eb17cbb23888ce3af8ff29f471f5bd5a2

services/audioflinger/Tracks.cpp

diff --git a/services/audioflinger/Tracks.cpp b/services/audioflinger/Tracks.cpp
index 1f75468..e676365 100644
--- a/services/audioflinger/Tracks.cpp
+++ b/services/audioflinger/Tracks.cpp
@@ -316,7 +316,6 @@
     mPresentationCompleteFrames(0),
     mFlags(flags),
     mFastIndex(-1),
-    mUnderrunCount(0),
     mCachedVolume(1.0),
     mIsInvalid(false),
     mAudioTrackServerProxy(NULL),
@@ -389,7 +388,7 @@
 /*static*/ void AudioFlinger::PlaybackThread::Track::appendDumpHeader(String8& result)
 {
     result.append("   Name Client Type Fmt Chn mask Session fCount S F SRate  "
-                  "L dB  R dB    Server Main buf  Aux Buf Flags Underruns\n");
+                  "L dB  R dB    Server Main buf  Aux Buf Flags UndFrmCnt\n");
 }
 
 void AudioFlinger::PlaybackThread::Track::dump(char* buffer, size_t size)
@@ -470,7 +469,7 @@
             (int)mMainBuffer,
             (int)mAuxBuffer,
             mCblk->mFlags,
-            mUnderrunCount,
+            mAudioTrackServerProxy->getUnderrunFrames(),
             nowInUnderrun);
 }
 
@@ -489,10 +488,7 @@
     buffer->frameCount = buf.mFrameCount;
     buffer->raw = buf.mRaw;
     if (buf.mFrameCount == 0) {
-        // only implemented so far for normal tracks, not fast tracks
-        mCblk->u.mStreaming.mUnderrunFrames += desiredFrames;
-        // FIXME also wake futex so that underrun is noticed more quickly
-        (void) android_atomic_or(CBLK_UNDERRUN, &mCblk->mFlags);
+        mAudioTrackServerProxy->tallyUnderrunFrames(desiredFrames);
     }
     return status;
 }