BufferQueue: Add producer buffer-released callback

Add a callback to the producer side, onBufferReleased, which will be
called every time the consumer releases a buffer back to the
BufferQueue. This will enable a buffer stream splitter to work
autonomously without having to block on dequeueBuffer.

The binder object used for the callback replaces the generic IBinder
token that was passed into IGraphicBufferProducer::connect to detect
the death of the producer. If a producer does not wish to listen for
buffer release events, it can pass in an instance of the
DummyProducerListener class defined in IProducerListener.h, if it even
cares about death events (BufferQueue doesn't enforce the token being
non-NULL, though perhaps we should).

Change-Id: I23935760673524abeafea2b58dccc3583b368710

1 files changed, 3 insertions, 2 deletions

diff --git a/libs/gui/Surface.cpp b/libs/gui/Surface.cpp
index 95f4084260..d1ef503f83 100644
--- a/libs/gui/Surface.cpp
+++ b/libs/gui/Surface.cpp
@@ -27,6 +27,7 @@
 
 #include <ui/Fence.h>
 
+#include <gui/IProducerListener.h>
 #include <gui/ISurfaceComposer.h>
 #include <gui/SurfaceComposerClient.h>
 #include <gui/GLConsumer.h>
@@ -513,10 +514,10 @@ int Surface::dispatchUnlockAndPost(va_list args __attribute__((unused))) {
 int Surface::connect(int api) {
     ATRACE_CALL();
     ALOGV("Surface::connect");
-    static sp<BBinder> sLife = new BBinder();
+    static sp<IProducerListener> listener = new DummyProducerListener();
     Mutex::Autolock lock(mMutex);
     IGraphicBufferProducer::QueueBufferOutput output;
-    int err = mGraphicBufferProducer->connect(sLife, api, mProducerControlledByApp, &output);
+    int err = mGraphicBufferProducer->connect(listener, api, mProducerControlledByApp, &output);
     if (err == NO_ERROR) {
         uint32_t numPendingBuffers = 0;
         output.deflate(&mDefaultWidth, &mDefaultHeight, &mTransformHint,