Example audio_utils FIFO and round-trip latency code

Change-Id: I4cd32012f651c8363817bd3d3dc5458f17a79ffe
diff --git a/src/devices/audio/avoiding_pi.jd b/src/devices/audio/avoiding_pi.jd
index 96d09a2..2e0a07a 100644
--- a/src/devices/audio/avoiding_pi.jd
+++ b/src/devices/audio/avoiding_pi.jd
@@ -289,6 +289,18 @@
 use non-blocking algorithms or reference a non-Android open source library.
 </p>
 
+<p>
+We have published an example non-blocking FIFO implementation that is specifically designed for
+application code.  See these files located in the platform source directory
+<code>frameworks/av/audio_utils</code>:
+</p>
+<ul>
+  <li><a href="https://android.googlesource.com/platform/system/media/+/master/audio_utils/include/audio_utils/fifo.h">include/audio_utils/fifo.h</a>
+  <li><a href="https://android.googlesource.com/platform/system/media/+/master/audio_utils/fifo.c">fifo.c</a>
+  <li><a href="https://android.googlesource.com/platform/system/media/+/master/audio_utils/include/audio_utils/roundup.h">include/audio_utils/roundup.h</a>
+  <li><a href="https://android.googlesource.com/platform/system/media/+/master/audio_utils/roundup.c">roundup.c</a>
+</ul>
+
 <h2 id="tools">Tools</h2>
 
 <p>
diff --git a/src/devices/audio/latency_measure.jd b/src/devices/audio/latency_measure.jd
index 90038bf..14574fb 100644
--- a/src/devices/audio/latency_measure.jd
+++ b/src/devices/audio/latency_measure.jd
@@ -119,6 +119,15 @@
   precise output latency or input latency values in isolation, but might be useful
   for establishing rough estimates.</p>
 
+<p>
+We have published an example implementation at
+<a href="https://android.googlesource.com/platform/frameworks/wilhelm/+/master/tests/examples/slesTestFeedback.cpp">slesTestFeedback.cpp</a>.
+This is a command-line app and is built using the platform build environment;
+however it should be straightforward to adopt the code for other environments.
+You will also need the <a href="avoiding_pi.html#nonBlockingAlgorithms">non-blocking</a> FIFO code
+located in the <code>audio_utils</code> library.
+</p>
+
 <h3 id="funplug">FunPlug</h3>
 
 <p>
diff --git a/src/devices/audio/terminology.jd b/src/devices/audio/terminology.jd
index bbe4e3f..ba2eb19 100644
--- a/src/devices/audio/terminology.jd
+++ b/src/devices/audio/terminology.jd
@@ -533,6 +533,13 @@
 <a href="http://developer.android.com/reference/android/media/AudioTrack.html">android.media.AudioTrack</a>.
 </dd>
 
+<dt>audio_utils</dt>
+<dd>
+An audio utility library for features such as PCM format conversion, WAV file I/O, and
+<a href="avoiding_pi.html#nonBlockingAlgorithms">non-blocking FIFO</a>,
+which is largely independent of the Android platform.
+</dd>
+
 <dt>client</dt>
 <dd>
 Usually same as application or app, but sometimes the "client" of