commit fd34a9310659aa53e9e10d6826651577a75f6447
author Phil Burk <philburk@google.com> Wed Jul 19 07:03:52 2017 -0700
committer Phil Burk <philburk@google.com> Thu Jul 20 16:10:41 2017 -0700
tree dc284d0eb17cbd8a023a2aec52d854c809b02c38
parent 679b6f6eaaeba35fcf96cb04a784308211d4b319

aaudio: reduce glitching by improving sleep timing

ALways sleep a minimum time to avoid busy wait in real-time thread.
Account for wakeup jitter in threads on the other side of a FIFO.
Avoid race condition that caused a longer sleep than necessary.
Fix calculation of mFreeRunning for capture mode.

Also added systrace logging, which was used to debug this.

Bug: 63814792
Test: Run GStomper on Walleye with MMAP on, see bug
Change-Id: I7b20098580ff454365425bd21e43c17ade532a0a

media/libaaudio/src/client/AudioEndpoint.cpp

diff --git a/media/libaaudio/src/client/AudioEndpoint.cpp b/media/libaaudio/src/client/AudioEndpoint.cpp
index 0684ed6..6ec285f 100644
--- a/media/libaaudio/src/client/AudioEndpoint.cpp
+++ b/media/libaaudio/src/client/AudioEndpoint.cpp
@@ -113,7 +113,8 @@
     return result;
 }
 
-aaudio_result_t AudioEndpoint::configure(const EndpointDescriptor *pEndpointDescriptor)
+aaudio_result_t AudioEndpoint::configure(const EndpointDescriptor *pEndpointDescriptor,
+                                         aaudio_direction_t   direction)
 {
     aaudio_result_t result = AudioEndpoint_validateDescriptor(pEndpointDescriptor);
     if (result != AAUDIO_OK) {
@@ -143,12 +144,20 @@
             descriptor->dataAddress
     );
 
-    // ============================ down data queue =============================
+    // ============================ data queue =============================
     descriptor = &pEndpointDescriptor->dataQueueDescriptor;
     ALOGV("AudioEndpoint::configure() data framesPerBurst = %d", descriptor->framesPerBurst);
-    ALOGV("AudioEndpoint::configure() data readCounterAddress = %p", descriptor->readCounterAddress);
-    mFreeRunning = descriptor->readCounterAddress == nullptr;
+    ALOGV("AudioEndpoint::configure() data readCounterAddress = %p",
+          descriptor->readCounterAddress);
+
+    // An example of free running is when the other side is read or written by hardware DMA
+    // or a DSP. It does not update its counter so we have to update it.
+    int64_t *remoteCounter = (direction == AAUDIO_DIRECTION_OUTPUT)
+                             ? descriptor->readCounterAddress // read by other side
+                             : descriptor->writeCounterAddress; // written by other side
+    mFreeRunning = (remoteCounter == nullptr);
     ALOGV("AudioEndpoint::configure() mFreeRunning = %d", mFreeRunning ? 1 : 0);
+
     int64_t *readCounterAddress = (descriptor->readCounterAddress == nullptr)
                                   ? &mDataReadCounter
                                   : descriptor->readCounterAddress;
@@ -173,13 +182,8 @@
     return mUpCommandQueue->read(commandPtr, 1);
 }
 
-aaudio_result_t AudioEndpoint::writeDataNow(const void *buffer, int32_t numFrames)
-{
-    return mDataQueue->write(buffer, numFrames);
-}
-
-void AudioEndpoint::getEmptyFramesAvailable(WrappingBuffer *wrappingBuffer) {
-    mDataQueue->getEmptyRoomAvailable(wrappingBuffer);
+int32_t AudioEndpoint::getEmptyFramesAvailable(WrappingBuffer *wrappingBuffer) {
+    return mDataQueue->getEmptyRoomAvailable(wrappingBuffer);
 }
 
 int32_t AudioEndpoint::getEmptyFramesAvailable()
@@ -187,7 +191,7 @@
     return mDataQueue->getFifoControllerBase()->getEmptyFramesAvailable();
 }
 
-void AudioEndpoint::getFullFramesAvailable(WrappingBuffer *wrappingBuffer)
+int32_t AudioEndpoint::getFullFramesAvailable(WrappingBuffer *wrappingBuffer)
 {
     return mDataQueue->getFullDataAvailable(wrappingBuffer);
 }