commit ec100976e0655acaa204c8800dfb83dadae20cc8
author John Reck <jreck@google.com> Thu Apr 05 16:41:41 2018 -0700
committer John Reck <jreck@google.com> Mon Apr 09 10:58:15 2018 -0700
tree d7bd2d10c7be8ea0ccec63e85c8365efb87edfe4
parent 413293ff626301e1ee9837f247c4d7321c59f472

Add support for render-ahead

For periods of time during which latency is less important
allow a client to request a deeper render-ahead pipeline.

The latency tradeoff results in less overall visual jank

Test: none, only used by macrobench

Change-Id: I516203b70bdc75b6415fa08bf9c4fb1b598b0102

libs/hwui/renderthread/CanvasContext.h

diff --git a/libs/hwui/renderthread/CanvasContext.h b/libs/hwui/renderthread/CanvasContext.h
index c2cc72a..8aaa8c1 100644
--- a/libs/hwui/renderthread/CanvasContext.h
+++ b/libs/hwui/renderthread/CanvasContext.h
@@ -78,7 +78,7 @@
     bool createOrUpdateLayer(RenderNode* node, const DamageAccumulator& dmgAccumulator,
                              ErrorHandler* errorHandler) {
         return mRenderPipeline->createOrUpdateLayer(node, dmgAccumulator, mWideColorGamut,
-                errorHandler);
+                                                    errorHandler);
     }
 
     /**
@@ -190,6 +190,8 @@
 
     IRenderPipeline* getRenderPipeline() { return mRenderPipeline.get(); }
 
+    void setRenderAheadDepth(int renderAhead);
+
 private:
     CanvasContext(RenderThread& thread, bool translucent, RenderNode* rootRenderNode,
                   IContextFactory* contextFactory, std::unique_ptr<IRenderPipeline> renderPipeline);
@@ -202,6 +204,7 @@
     void freePrefetchedLayers();
 
     bool isSwapChainStuffed();
+    void updateBufferCount();
 
     SkRect computeDirtyRect(const Frame& frame, SkRect* dirty);
 
@@ -227,6 +230,7 @@
 
     RingBuffer<SwapHistory, 3> mSwapHistory;
     int64_t mFrameNumber = -1;
+    int mRenderAheadDepth = 0;
 
     // last vsync for a dropped frame due to stuffed queue
     nsecs_t mLastDropVsync = 0;