SurfaceFlinger: Fix PTS on stale buffers
SurfaceFlinger's (Layer's) shadow copy of the BufferQueue queue was
getting out of sync for a few reasons. This change fixes these by
doing the following:
- Adds a check to re-synchronize the shadow copy every time we
successfully acquire a buffer by first dropping stale buffers before
removing the current buffer.
- Avoids trying to perform updates for buffers which have been rejected
(for incorrect dimensions) by SurfaceFlinger.
- Adds IGraphicBufferConsumer::setShadowQueueSize, which allows the
consumer to notify the BufferQueue that it is maintaining a shadow
copy of the queue and prevents it from dropping so many buffers
during acquireBuffer that it ends up returning a buffer for which the
consumer has not yet received an onFrameAvailable call.
Bug: 20096136
Change-Id: I78d0738428005fc19b3be85cc8f1db498043612f
(cherry picked from commit 2e36f2283f48ab764b496490c73a132acf21df3a)
diff --git a/include/gui/BufferQueueConsumer.h b/include/gui/BufferQueueConsumer.h
index 9c91fc7..0f42613 100644
--- a/include/gui/BufferQueueConsumer.h
+++ b/include/gui/BufferQueueConsumer.h
@@ -148,6 +148,9 @@
// Retrieve the sideband buffer stream, if any.
virtual sp<NativeHandle> getSidebandStream() const;
+ // See IGraphicBufferConsumer::setShadowQueueSize
+ virtual void setShadowQueueSize(size_t size);
+
// dump our state in a String
virtual void dump(String8& result, const char* prefix) const;
diff --git a/include/gui/BufferQueueCore.h b/include/gui/BufferQueueCore.h
index e3624b7..a22015c 100644
--- a/include/gui/BufferQueueCore.h
+++ b/include/gui/BufferQueueCore.h
@@ -274,6 +274,13 @@
// mBufferAge tracks the age of the contents of the most recently dequeued
// buffer as the number of frames that have elapsed since it was last queued
uint64_t mBufferAge;
+
+ // mConsumerHasShadowQueue determines if acquireBuffer should be more
+ // cautious about dropping buffers so that it always returns a buffer that
+ // is represented in the consumer's shadow queue.
+ bool mConsumerHasShadowQueue;
+ size_t mConsumerShadowQueueSize;
+
}; // class BufferQueueCore
} // namespace android
diff --git a/include/gui/IGraphicBufferConsumer.h b/include/gui/IGraphicBufferConsumer.h
index 8f31b55..0be09a2 100644
--- a/include/gui/IGraphicBufferConsumer.h
+++ b/include/gui/IGraphicBufferConsumer.h
@@ -248,6 +248,11 @@
// Retrieve the sideband buffer stream, if any.
virtual sp<NativeHandle> getSidebandStream() const = 0;
+ // setShadowQueueSize notifies the BufferQueue that the consumer is
+ // shadowing its queue and allows it to limit the number of buffers it is
+ // permitted to drop during acquire so as to not get out of sync.
+ virtual void setShadowQueueSize(size_t size) = 0;
+
// dump state into a string
virtual void dump(String8& result, const char* prefix) const = 0;