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/BufferQueueCore.h b/include/gui/BufferQueueCore.h
index a6065a9..9a43516 100644
--- a/include/gui/BufferQueueCore.h
+++ b/include/gui/BufferQueueCore.h
@@ -266,6 +266,10 @@
// mIsAllocatingCondition is a condition variable used by producers to wait until mIsAllocating
// becomes false.
mutable Condition mIsAllocatingCondition;
+
+ // mAllowAllocation determines whether dequeueBuffer is allowed to allocate
+ // new buffers
+ bool mAllowAllocation;
}; // class BufferQueueCore
} // namespace android
diff --git a/include/gui/BufferQueueProducer.h b/include/gui/BufferQueueProducer.h
index f794ea3..ed660fb 100644
--- a/include/gui/BufferQueueProducer.h
+++ b/include/gui/BufferQueueProducer.h
@@ -172,6 +172,9 @@
virtual void allocateBuffers(bool async, uint32_t width, uint32_t height,
PixelFormat format, uint32_t usage);
+ // See IGraphicBufferProducer::allowAllocation
+ virtual status_t allowAllocation(bool allow);
+
private:
// This is required by the IBinder::DeathRecipient interface
virtual void binderDied(const wp<IBinder>& who);
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;
};
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