libgui: Allow an IGBProducer to disable allocation
Adds a new method IGBP::allowAllocation, which controls whether
dequeueBuffer is permitted to allocate a new buffer. If allocation is
disallowed, dequeueBuffer will block or return an error as it
normally would (as controlled by *ControlledByApp).
If there are free buffers, but they are not of the correct dimensions,
format, or usage, they may be freed if a more suitable buffer is not
found first.
Bug: 19801715
Change-Id: I0d604958b78b2fd775c2547690301423f9a52165
diff --git a/include/gui/IGraphicBufferProducer.h b/include/gui/IGraphicBufferProducer.h
index 2d99f24..5c50b2b 100644
--- a/include/gui/IGraphicBufferProducer.h
+++ b/include/gui/IGraphicBufferProducer.h
@@ -458,6 +458,18 @@
// allocated, this function has no effect.
virtual void allocateBuffers(bool async, uint32_t width, uint32_t height,
PixelFormat format, uint32_t usage) = 0;
+
+ // Sets whether dequeueBuffer is allowed to allocate new buffers.
+ //
+ // Normally dequeueBuffer does not discriminate between free slots which
+ // already have an allocated buffer and those which do not, and will
+ // allocate a new buffer if the slot doesn't have a buffer or if the slot's
+ // buffer doesn't match the requested size, format, or usage. This method
+ // allows the producer to restrict the eligible slots to those which already
+ // have an allocated buffer of the correct size, format, and usage. If no
+ // eligible slot is available, dequeueBuffer will block or return an error
+ // as usual.
+ virtual status_t allowAllocation(bool allow) = 0;
};
// ----------------------------------------------------------------------------