Improve underrun handling for fast tracks
Maintain more accurate accounting of type of underrun.
Automatically remove track from active list after a series of "empty" underruns.
Change-Id: If042bf80e1790dcaaf195c99dc9c0ed9b55382c1
diff --git a/services/audioflinger/FastMixer.h b/services/audioflinger/FastMixer.h
index e2ed553..e95abf6 100644
--- a/services/audioflinger/FastMixer.h
+++ b/services/audioflinger/FastMixer.h
@@ -17,6 +17,7 @@
#ifndef ANDROID_AUDIO_FAST_MIXER_H
#define ANDROID_AUDIO_FAST_MIXER_H
+#include <utils/Debug.h>
#include <utils/Thread.h>
extern "C" {
#include "../private/bionic_futex.h"
@@ -42,16 +43,38 @@
}; // class FastMixer
+// Describes the underrun status for a single "pull" attempt
+enum FastTrackUnderrunStatus {
+ UNDERRUN_FULL, // framesReady() is full frame count, no underrun
+ UNDERRUN_PARTIAL, // framesReady() is non-zero but < full frame count, partial underrun
+ UNDERRUN_EMPTY, // framesReady() is zero, total underrun
+};
+
+// Underrun counters are not reset to zero for new tracks or if track generation changes.
+// This packed representation is used to keep the information atomic.
+union FastTrackUnderruns {
+ FastTrackUnderruns() { mAtomic = 0;
+ COMPILE_TIME_ASSERT_FUNCTION_SCOPE(sizeof(FastTrackUnderruns) == sizeof(uint32_t)); }
+ FastTrackUnderruns(const FastTrackUnderruns& copyFrom) : mAtomic(copyFrom.mAtomic) { }
+ FastTrackUnderruns& operator=(const FastTrackUnderruns& rhs)
+ { if (this != &rhs) mAtomic = rhs.mAtomic; return *this; }
+ struct {
+#define UNDERRUN_BITS 10
+#define UNDERRUN_MASK ((1 << UNDERRUN_BITS) - 1)
+ uint32_t mFull : UNDERRUN_BITS; // framesReady() is full frame count
+ uint32_t mPartial : UNDERRUN_BITS; // framesReady() is non-zero but < full frame count
+ uint32_t mEmpty : UNDERRUN_BITS; // framesReady() is zero
+ FastTrackUnderrunStatus mMostRecent : 2; // status of most recent framesReady()
+ } mBitFields;
+private:
+ uint32_t mAtomic;
+};
+
// Represents the dump state of a fast track
struct FastTrackDump {
- FastTrackDump() : mUnderruns(0) { }
+ FastTrackDump() { }
/*virtual*/ ~FastTrackDump() { }
- uint32_t mUnderruns; // Underrun status, represented as follows:
- // bit 0 == 0 means not currently in underrun
- // bit 0 == 1 means currently in underrun
- // bits 1 to 31 == total number of underruns
- // Not reset to zero for new tracks or if track generation changes.
- // This representation is used to keep the information atomic.
+ FastTrackUnderruns mUnderruns;
};
// The FastMixerDumpState keeps a cache of FastMixer statistics that can be logged by dumpsys.