commit 2812d9ea3a3a33142dd8e23c9d949c498d6f7a12
author Phil Burk <philburk@google.com> Mon Jan 04 10:34:30 2016 -0800
committer Phil Burk <philburk@google.com> Sat Jan 16 11:21:38 2016 -0800
tree 5079c758817d0c42b3f7ade661366fdae25fe5d1
parent e0db30868d9734f95a02df516dd0dc6a7226474b

AudioTrack: Add getUnderrunCount()

This allows an app to detect application-level output glitches.
Underrun counts survive track recreation.

Change-Id: I8eb14e92f6fc1007718a29b0666ab51ace30cdb8
Bug: 25641253
Signed-off-by: Phil Burk <philburk@google.com>

media/libmedia/AudioTrack.cpp

diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index 5e14940..31e88c3 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -493,6 +493,7 @@
     mPreviousTimestampValid = false;
     mTimestampStartupGlitchReported = false;
     mRetrogradeMotionReported = false;
+    mUnderrunCountOffset = 0;
 
     return NO_ERROR;
 }
@@ -2112,6 +2113,9 @@
         return DEAD_OBJECT;
     }
 
+    // Save so we can return count since creation.
+    mUnderrunCountOffset = getUnderrunCount_l();
+
     // save the old static buffer position
     size_t bufferPosition = 0;
     int loopCount = 0;
@@ -2427,6 +2431,17 @@
     return NO_ERROR;
 }
 
+uint32_t AudioTrack::getUnderrunCount() const
+{
+    AutoMutex lock(mLock);
+    return getUnderrunCount_l();
+}
+
+uint32_t AudioTrack::getUnderrunCount_l() const
+{
+    return mProxy->getUnderrunCount() + mUnderrunCountOffset;
+}
+
 uint32_t AudioTrack::getUnderrunFrames() const
 {
     AutoMutex lock(mLock);

media/libmedia/AudioTrackShared.cpp

diff --git a/media/libmedia/AudioTrackShared.cpp b/media/libmedia/AudioTrackShared.cpp
index 9fad500..716a614 100644
--- a/media/libmedia/AudioTrackShared.cpp
+++ b/media/libmedia/AudioTrackShared.cpp
@@ -781,10 +781,25 @@
 void AudioTrackServerProxy::tallyUnderrunFrames(uint32_t frameCount)
 {
     audio_track_cblk_t* cblk = mCblk;
-    cblk->u.mStreaming.mUnderrunFrames += frameCount;
+    if (frameCount > 0) {
+        cblk->u.mStreaming.mUnderrunFrames += frameCount;
 
-    // FIXME also wake futex so that underrun is noticed more quickly
-    (void) android_atomic_or(CBLK_UNDERRUN, &cblk->mFlags);
+        if (!mUnderrunning) { // start of underrun?
+            mUnderrunCount++;
+            cblk->u.mStreaming.mUnderrunCount = mUnderrunCount;
+            mUnderrunning = true;
+            ALOGV("tallyUnderrunFrames(%3u) at uf = %u, bump mUnderrunCount = %u",
+                frameCount, cblk->u.mStreaming.mUnderrunFrames, mUnderrunCount);
+        }
+
+        // FIXME also wake futex so that underrun is noticed more quickly
+        (void) android_atomic_or(CBLK_UNDERRUN, &cblk->mFlags);
+    } else {
+        ALOGV_IF(mUnderrunning,
+            "tallyUnderrunFrames(%3u) at uf = %u, underrun finished",
+            frameCount, cblk->u.mStreaming.mUnderrunFrames);
+        mUnderrunning = false; // so we can detect the next edge
+    }
 }
 
 AudioPlaybackRate AudioTrackServerProxy::getPlaybackRate()
@@ -1010,7 +1025,7 @@
     buffer->mNonContig = 0;
 }
 
-void StaticAudioTrackServerProxy::tallyUnderrunFrames(uint32_t frameCount __unused)
+void StaticAudioTrackServerProxy::tallyUnderrunFrames(uint32_t frameCount)
 {
     // Unlike AudioTrackServerProxy::tallyUnderrunFrames() used for streaming tracks,
     // we don't have a location to count underrun frames.  The underrun frame counter
@@ -1018,7 +1033,9 @@
     // possible for static buffer tracks other than at end of buffer, so this is not a loss.
 
     // FIXME also wake futex so that underrun is noticed more quickly
-    (void) android_atomic_or(CBLK_UNDERRUN, &mCblk->mFlags);
+    if (frameCount > 0) {
+        (void) android_atomic_or(CBLK_UNDERRUN, &mCblk->mFlags);
+    }
 }
 
 // ---------------------------------------------------------------------------