Non-blocking audio I/O interface, WIP

Yet another abstraction similar to AudioTrack::Buffer and AudioBufferProvider,
but with support for streaming, non-blocking, and eventually PTS.

This is intended to be used as follows:
 - primary HAL output stream implements a Sink
 - primary HAL input stream implements a Source
 - Pipe implements a Sink
 - PipeReader implements a Source or TimedSource (not shown yet),
   which supports "read at PTS"
 - fast AudioTrack on server side will implement a Source using cblk
 - normal AudioTrack on server side will not be changed initially
 - fast AudioRecord on server side will implement a Sink using cblk
 - normal AudioRecord on server side will not be changed initially
 - fast mixer thread will read from Sources and write to a Sink,
   or (unlikely) implement a Source and multiple Sinks
 - Visualization and PCM logger will read from Source or TimedSource
 - A2DP normal mixer will be connected directly to its output stream
   and there will be a kind of OutputTrack for duplication that will
   read from a Sink with non-blocking write fed by the fast mixer.

Patch set 3 changes:
 - Add more implementations of NBAIO interfaces:
   added SourceAudioBufferProvider, MonoPipe, MonoPipeReader.
 - Added Format_sampleRate and Format_channelCount.
 - Extract out the roundUp() method.
 - Respond to most comments from previous code review.
 - The new classes are untested.

Patch set 4 changes:
 - Fix bugs in MonoPipe::write() and MonoPipeReader::read()
 - Fix bug initializing mFrameBitShift too early
 - renamed roundUp() to roundup()
 - Fix Android.mk
 - Add LOG_TAG an LOG_NDEBUG, use ALOG_ASSERT and utils/Log.h instead of assert
 - Fix build warnings
 - Move constructor and destructor bodies from .h to .cpp
 - Line length 100
 - Following naming conventions for #include double-include protector macros
 - Include what you use
 - More NBAIO logging
 - MonoPipe write can be blocking

Patch set 5 changes:
 - Address code review comments
 - Use a static library so unused implementations don't take memory
 - Comment out libsndfile dependency
 - Remove debugging LOGV and LOG_NDEBUG

Patch set 6 changes (would be 6 at old location, actually 2 at new location):
 - Address code review comments on patchset 5
 - For MonoPipe, allow the full pipe to be used, no need to omit one slot
 - Don't do atomic releasing stores unless needed

Still to do:
 - I'm not happy with the Pipe class names
 - Update build/ for new static library?

Change-Id: Ie6c61f05ce06b676b033be448a8ef9025a2ffcfd

1 files changed, 24 insertions, 0 deletions

diff --git a/services/audioflinger/Android.mk b/services/audioflinger/Android.mk
index 257f62c..2cf77ce 100644
--- a/services/audioflinger/Android.mk
+++ b/services/audioflinger/Android.mk
@@ -2,6 +2,29 @@ LOCAL_PATH:= $(call my-dir)
 
 include $(CLEAR_VARS)
 
+LOCAL_SRC_FILES := \
+    AudioBufferProviderSource.cpp   \
+    AudioStreamOutSink.cpp          \
+    AudioStreamInSource.cpp         \
+    NBAIO.cpp                       \
+    MonoPipe.cpp                    \
+    MonoPipeReader.cpp              \
+    Pipe.cpp                        \
+    PipeReader.cpp                  \
+    roundup.c                       \
+    SourceAudioBufferProvider.cpp
+
+# libsndfile license is incompatible; uncomment to use for local debug only
+#LOCAL_SRC_FILES += LibsndfileSink.cpp LibsndfileSource.cpp
+#LOCAL_C_INCLUDES += path/to/libsndfile/src
+#LOCAL_STATIC_LIBRARIES += libsndfile
+
+LOCAL_MODULE := libnbaio
+
+include $(BUILD_STATIC_LIBRARY)
+
+include $(CLEAR_VARS)
+
 LOCAL_SRC_FILES:=               \
     AudioFlinger.cpp            \
     AudioMixer.cpp.arm          \
@@ -31,6 +54,7 @@ LOCAL_SHARED_LIBRARIES := \
     libpowermanager
 
 LOCAL_STATIC_LIBRARIES := \
+    libnbaio \
     libcpustats \
     libmedia_helper