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, 2 insertions, 10 deletions

diff --git a/include/gui/BufferQueue.h b/include/gui/BufferQueue.h
index f74dc26245..85bf5a9aca 100644
--- a/include/gui/BufferQueue.h
+++ b/include/gui/BufferQueue.h
@@ -232,16 +232,8 @@ public:
     // will usually be the one obtained from dequeueBuffer.
     virtual void cancelBuffer(int buf, const sp<Fence>& fence);
 
-    // connect attempts to connect a producer API to the BufferQueue.  This
-    // must be called before any other IGraphicBufferProducer methods are
-    // called except for getAllocator.  A consumer must already be connected.
-    //
-    // This method will fail if connect was previously called on the
-    // BufferQueue and no corresponding disconnect call was made (i.e. if
-    // it's still connected to a producer).
-    //
-    // APIs are enumerated in window.h (e.g. NATIVE_WINDOW_API_CPU).
-    virtual status_t connect(const sp<IBinder>& token,
+    // See IGraphicBufferProducer::connect
+    virtual status_t connect(const sp<IProducerListener>& listener,
             int api, bool producerControlledByApp, QueueBufferOutput* output);
 
     // disconnect attempts to disconnect a producer API from the BufferQueue.