Push HWC cache slot generation down into CompositionEngine

Stop caching buffers inside SurfaceFlinger and remove the tight coupling
between SurfaceFlinger's ClientCache and the Hardware Composer cache.
This allows a better seperation of responsibility, where buffer cache
management is not split between HwcSlotGenerator and HwcBufferCache, but
is instead solely handled by HwcBufferCache.

Note that FramebufferSurface and VirtualDisplaySurface no longer use
HwcBufferCache, but instead use their own cache slot management that
is solely based on BufferQueue slot numbers.

Also do minor refactoring in FramebufferSurface to simplify code.

Bug: 258196272
Test: started and stopped multiple YouTube videos on adt4 and verified
no change in graphic buffer usage
Test: atest HwcBufferCacheTest
Test: atest OutputPrepareTest

Change-Id: Ica7955ab4bc70e3c70207390e36dff73a2fc4949

1 files changed, 1 insertions, 11 deletions

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 0017af0476..b0ee850541 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -144,7 +144,6 @@ Layer::Layer(const LayerCreationArgs& args)
         mLayerCreationFlags(args.flags),
         mBorderEnabled(false),
         mTextureName(args.textureName),
-        mHwcSlotGenerator(sp<HwcSlotGenerator>::make()),
         mLayerFE(args.flinger->getFactory().createLayerFE(mName)) {
     ALOGV("Creating Layer %s", getDebugName());
 
@@ -573,9 +572,6 @@ void Layer::preparePerFrameBufferCompositionState() {
     }
 
     snapshot->buffer = getBuffer();
-    snapshot->bufferSlot = (mBufferInfo.mBufferSlot == BufferQueue::INVALID_BUFFER_SLOT)
-            ? 0
-            : mBufferInfo.mBufferSlot;
     snapshot->acquireFence = mBufferInfo.mFence;
     snapshot->frameNumber = mBufferInfo.mFrameNumber;
     snapshot->sidebandStreamHasFrame = false;
@@ -2840,7 +2836,7 @@ bool Layer::setPosition(float x, float y) {
 bool Layer::setBuffer(std::shared_ptr<renderengine::ExternalTexture>& buffer,
                       const BufferData& bufferData, nsecs_t postTime, nsecs_t desiredPresentTime,
                       bool isAutoTimestamp, std::optional<nsecs_t> dequeueTime,
-                      const FrameTimelineInfo& info, int hwcBufferSlot) {
+                      const FrameTimelineInfo& info) {
     ATRACE_FORMAT("setBuffer %s - hasBuffer=%s", getDebugName(), (buffer ? "true" : "false"));
     if (!buffer) {
         return false;
@@ -2886,7 +2882,6 @@ bool Layer::setBuffer(std::shared_ptr<renderengine::ExternalTexture>& buffer,
     mDrawingState.releaseBufferListener = bufferData.releaseBufferListener;
     mDrawingState.buffer = std::move(buffer);
     mDrawingState.clientCacheId = bufferData.cachedBuffer;
-    mDrawingState.hwcBufferSlot = hwcBufferSlot;
     mDrawingState.acquireFence = bufferData.flags.test(BufferData::BufferDataChange::fenceChanged)
             ? bufferData.acquireFence
             : Fence::NO_FENCE;
@@ -3185,7 +3180,6 @@ void Layer::gatherBufferInfo() {
     mBufferInfo.mHdrMetadata = mDrawingState.hdrMetadata;
     mBufferInfo.mApi = mDrawingState.api;
     mBufferInfo.mTransformToDisplayInverse = mDrawingState.transformToDisplayInverse;
-    mBufferInfo.mBufferSlot = mDrawingState.hwcBufferSlot;
 }
 
 Rect Layer::computeBufferCrop(const State& s) {
@@ -3968,10 +3962,6 @@ void Layer::updateRelativeMetadataSnapshot(const LayerMetadata& relativeLayerMet
     }
 }
 
-int Layer::getHwcCacheSlot(const client_cache_t& clientCacheId) {
-    return mHwcSlotGenerator->getHwcCacheSlot(clientCacheId);
-}
-
 LayerSnapshotGuard::LayerSnapshotGuard(Layer* layer) : mLayer(layer) {
     if (mLayer) {
         mLayer->mLayerFE->mSnapshot = std::move(mLayer->mSnapshot);