libgui: Add discardFreeBuffers callback to producer

This enables buffer producer to clear its buffer caches.

Test: Camera CTS, libgui_test
Bug: 136677409
Bug: 145617243
Change-Id: I7f46e977f3edc3b08177654531745d8ca0b86889
Merged-In: I7f46e977f3edc3b08177654531745d8ca0b86889

3 files changed, 55 insertions, 1 deletions

diff --git a/libs/gui/include/gui/BufferQueueCore.h b/libs/gui/include/gui/BufferQueueCore.h
index 690a85f39..17617bce1 100644
--- a/libs/gui/include/gui/BufferQueueCore.h
+++ b/libs/gui/include/gui/BufferQueueCore.h
@@ -189,8 +189,12 @@ private:
     sp<IProducerListener> mLinkedToDeath;
 
     // mConnectedProducerListener is used to handle the onBufferReleased
-    // notification.
+    // and onBuffersDiscarded notification.
     sp<IProducerListener> mConnectedProducerListener;
+    // mBufferReleasedCbEnabled is used to indicate whether onBufferReleased()
+    // callback is registered by the listener. When set to false,
+    // mConnectedProducerListener will not trigger onBufferReleased() callback.
+    bool mBufferReleasedCbEnabled;
 
     // mSlots is an array of buffer slots that must be mirrored on the producer
     // side. This allows buffer ownership to be transferred between the producer
diff --git a/libs/gui/include/gui/IProducerListener.h b/libs/gui/include/gui/IProducerListener.h
index a13d8e494..32a3690ff 100644
--- a/libs/gui/include/gui/IProducerListener.h
+++ b/libs/gui/include/gui/IProducerListener.h
@@ -17,6 +17,8 @@
 #ifndef ANDROID_GUI_IPRODUCERLISTENER_H
 #define ANDROID_GUI_IPRODUCERLISTENER_H
 
+#include <vector>
+
 #include <android/hardware/graphics/bufferqueue/1.0/IProducerListener.h>
 #include <android/hardware/graphics/bufferqueue/2.0/IProducerListener.h>
 #include <binder/IInterface.h>
@@ -44,6 +46,9 @@ public:
     // multiple threads.
     virtual void onBufferReleased() = 0; // Asynchronous
     virtual bool needsReleaseNotify() = 0;
+    // onBuffersFreed is called from IGraphicBufferConsumer::discardFreeBuffers
+    // to notify the producer that certain free buffers are discarded by the consumer.
+    virtual void onBuffersDiscarded(const std::vector<int32_t>& slots) = 0; // Asynchronous
 };
 
 class IProducerListener : public ProducerListener, public IInterface
@@ -65,6 +70,7 @@ public:
     virtual status_t onTransact(uint32_t code, const Parcel& data,
             Parcel* reply, uint32_t flags = 0);
     virtual bool needsReleaseNotify();
+    virtual void onBuffersDiscarded(const std::vector<int32_t>& slots);
 };
 
 class DummyProducerListener : public BnProducerListener
diff --git a/libs/gui/include/gui/Surface.h b/libs/gui/include/gui/Surface.h
index 5c6a1ee38..a5641b07e 100644
--- a/libs/gui/include/gui/Surface.h
+++ b/libs/gui/include/gui/Surface.h
@@ -20,6 +20,7 @@
 #include <gui/BufferQueueDefs.h>
 #include <gui/HdrMetadata.h>
 #include <gui/IGraphicBufferProducer.h>
+#include <gui/IProducerListener.h>
 
 #include <ui/ANativeObjectBase.h>
 #include <ui/GraphicTypes.h>
@@ -35,6 +36,21 @@ namespace android {
 
 class ISurfaceComposer;
 
+/* This is the same as ProducerListener except that onBuffersDiscarded is
+ * called with a vector of graphic buffers instead of buffer slots.
+ */
+class SurfaceListener : public virtual RefBase
+{
+public:
+    SurfaceListener() = default;
+    virtual ~SurfaceListener() = default;
+
+    virtual void onBufferReleased() = 0;
+    virtual bool needsReleaseNotify() = 0;
+
+    virtual void onBuffersDiscarded(const std::vector<sp<GraphicBuffer>>& buffers) = 0;
+};
+
 /*
  * An implementation of ANativeWindow that feeds graphics buffers into a
  * BufferQueue.
@@ -283,6 +299,10 @@ public:
             sp<Fence>* outFence);
     virtual int attachBuffer(ANativeWindowBuffer*);
 
+    virtual int connect(
+            int api, bool reportBufferRemoval,
+            const sp<SurfaceListener>& sListener);
+
     // When client connects to Surface with reportBufferRemoval set to true, any buffers removed
     // from this Surface will be collected and returned here. Once this method returns, these
     // buffers will no longer be referenced by this Surface unless they are attached to this
@@ -299,6 +319,26 @@ protected:
     enum { NUM_BUFFER_SLOTS = BufferQueueDefs::NUM_BUFFER_SLOTS };
     enum { DEFAULT_FORMAT = PIXEL_FORMAT_RGBA_8888 };
 
+    class ProducerListenerProxy : public BnProducerListener {
+    public:
+        ProducerListenerProxy(wp<Surface> parent, sp<SurfaceListener> listener)
+               : mParent(parent), mSurfaceListener(listener) {}
+        virtual ~ProducerListenerProxy() {}
+
+        virtual void onBufferReleased() {
+            mSurfaceListener->onBufferReleased();
+        }
+
+        virtual bool needsReleaseNotify() {
+            return mSurfaceListener->needsReleaseNotify();
+        }
+
+        virtual void onBuffersDiscarded(const std::vector<int32_t>& slots);
+    private:
+        wp<Surface> mParent;
+        sp<SurfaceListener> mSurfaceListener;
+    };
+
     void querySupportedTimestampsLocked() const;
 
     void freeAllBuffers();
@@ -466,6 +506,10 @@ protected:
 
     bool mReportRemovedBuffers = false;
     std::vector<sp<GraphicBuffer>> mRemovedBuffers;
+
+    sp<IProducerListener> mListenerProxy;
+    status_t getAndFlushBuffersFromSlots(const std::vector<int32_t>& slots,
+            std::vector<sp<GraphicBuffer>>* outBuffers);
 };
 
 } // namespace android