南京做网站南京乐识好,国外最新设计产品,怎么制作一个国外网站,link友情买卖BLASTBufferQueue端的GraphicBuffer怎么和SurfaceFlinger端的BufferStateLayer关联上 引言
在跟进hwc_layer是如何产生的#xff0c;并如何被填充上GraphicBuffer的#xff0c;怎么也找不到被填充的GraphicBuffer的来源#xff0c;最终找到了#xff0c;它的来源是客户端的… BLASTBufferQueue端的GraphicBuffer怎么和SurfaceFlinger端的BufferStateLayer关联上 引言
在跟进hwc_layer是如何产生的并如何被填充上GraphicBuffer的怎么也找不到被填充的GraphicBuffer的来源最终找到了它的来源是客户端的BLASTBufferQueue传递过来的我们这里跟进下这个流程。 这里使用的代码是Android 13 aosp 一. BLASTBufferQueue是如何传递GraphicBuffer到SurfaceFlinger端的BufferStateLayer的
当BufferQueueProducer完成绘制调用queueBuffer后会调用BLASTBufferQueue::onFrameAvailable。
///rameworks/native/libs/gui/BLASTBufferQueue.cpp
void BLASTBufferQueue::onFrameAvailable(const BufferItem item) {...acquireNextBufferLocked(mSyncTransaction)...
}void BLASTBufferQueue::acquireNextBufferLocked(const std::optionalSurfaceComposerClient::Transaction* transaction) {...status_t status mBufferItemConsumer-acquireBuffer(bufferItem, 0 /* expectedPresent */, false); auto buffer bufferItem.mGraphicBuffer;t-setBuffer(mSurfaceControl, buffer, fence, bufferItem.mFrameNumber, releaseBufferCallback);t-setApplyToken(mApplyToken).apply(false, true);...
}
apply最终会通过Binder调用到SurfaceFlinger的setTransactionState我们接着往下看:
status_t SurfaceFlinger::setTransactionState(const FrameTimelineInfo frameTimelineInfo, const VectorComposerState states,const VectorDisplayState displays, uint32_t flags, const spIBinder applyToken,const InputWindowCommands inputWindowCommands, int64_t desiredPresentTime,bool isAutoTimestamp, const client_cache_t uncacheBuffer, bool hasListenerCallbacks,const std::vectorListenerCallbacks listenerCallbacks, uint64_t transactionId) {...queueTransaction(state);//将相关的transaction状态存起来...} 后续vsync会触发SurfaceFlinger执行如下逻辑:
MessageQueue::Handler::handleMessagecompositor.commitSurfaceFlinger::commitflushTransactionQueuesSurfaceFlinger::applyTransactionStateSurfaceFlinger::setClientStateLockedlayer-setBufferuint32_t SurfaceFlinger::setClientStateLocked(const FrameTimelineInfo frameTimelineInfo,ComposerState composerState,int64_t desiredPresentTime, bool isAutoTimestamp,int64_t postTime, uint32_t permissions) {layer_state_t s composerState.state;spLayer layer nullptr;layer fromHandle(s.surface).promote();//关键点这个layer是怎么获取的if (what layer_state_t::eBufferChanged) {std::shared_ptrrenderengine::ExternalTexture buffer getExternalTextureFromBufferData(*s.bufferData, layer-getDebugName());//这里并不是真的纹理而是命名像而已if (layer-setBuffer(buffer, *s.bufferData, postTime, desiredPresentTime, isAutoTimestamp,dequeueBufferTimestamp, frameTimelineInfo)) {flags | eTraversalNeeded;}}
}这里我们看下fromHandle的实现:
//SurfaceFlinger.cpp
wpLayer SurfaceFlinger::fromHandle(const spIBinder handle) const {return Layer::fromHandle(handle);
}//Layer.cpp
wpLayer Layer::fromHandle(const spIBinder handleBinder) {if (handleBinder nullptr) {return nullptr;}BBinder* b handleBinder-localBinder();if (b nullptr || b-getInterfaceDescriptor() ! Handle::kDescriptor) {return nullptr;}// We can safely cast this binder since its local and we verified its interface descriptor.spHandle handle static_castHandle*(handleBinder.get());return handle-owner;
}那么这个Layer对应的Handle是什么时候被构建的呢是什么时候呢。
status_t SurfaceFlinger::createLayer(LayerCreationArgs args, spIBinder* outHandle,const spIBinder parentHandle, int32_t* outLayerId,const spLayer parentLayer, uint32_t* outTransformHint) {...spLayer layer; createBufferStateLayer(args, outHandle, layer)...
} status_t SurfaceFlinger::createBufferStateLayer(LayerCreationArgs args, spIBinder* handle,spLayer* outLayer) {args.textureName getNewTexture();*outLayer getFactory().createBufferStateLayer(args);*handle (*outLayer)-getHandle();return NO_ERROR;
}//frameworks/native/services/surfaceflinger/Layer.cpp
spIBinder Layer::getHandle() {Mutex::Autolock _l(mLock);if (mGetHandleCalled) {ALOGE(Get handle called twice );return nullptr;}mGetHandleCalled true;return new Handle(mFlinger, this);
}//frameworks/native/services/surfaceflinger/Layer.h
class Handle : public BBinder, public LayerCleaner {
public:Handle(const spSurfaceFlinger flinger, const spLayer layer): LayerCleaner(flinger, layer, this), owner(layer) {}const String16 getInterfaceDescriptor() const override { return kDescriptor; }static const String16 kDescriptor;wpLayer owner;
};
...
}这里我们要怎么理解这个Handle呢它是对Layer的一个封装不管是BufferStateLayer还是其它的通过它可以让Layer在Binder中传递。
我们接着继续往下看layer-setBuffer会调用子类的setBuffer子类是BufferStateLayer
//frameworks/native/services/surfaceflinger/BufferStateLayer.cpp
bool BufferStateLayer::setBuffer(std::shared_ptrrenderengine::ExternalTexture buffer,const BufferData bufferData, nsecs_t postTime,nsecs_t desiredPresentTime, bool isAutoTimestamp,std::optionalnsecs_t dequeueTime,const FrameTimelineInfo info) {...mDrawingState.frameNumber frameNumber;mDrawingState.releaseBufferListener bufferData.releaseBufferListener;mDrawingState.buffer std::move(buffer);mDrawingState.clientCacheId bufferData.cachedBuffer;setTransactionFlags(eTransactionNeeded);...
}这里只是把buffer赋值给mDrawingState.buffer了肯定有地方把mDrawingState.buffer赋值mBufferInfo.mBuffer
接着找在updateActiveBuffer找到了mBufferInfo.mBuffer s.buffer。updateActiveBuffer又是在哪里调用的呢
status_t BufferStateLayer::updateActiveBuffer() {const State s(getDrawingState());...mBufferInfo.mBuffer s.buffer;mBufferInfo.mFence s.acquireFence;mBufferInfo.mFrameNumber s.frameNumber;...
}在BufferStateLayer的父类BufferLayer::latchBuffer里调用: bool BufferLayer::latchBuffer(bool recomputeVisibleRegions, nsecs_t latchTime,nsecs_t expectedPresentTime) {
... ...status_t err updateTexImage(recomputeVisibleRegions, latchTime, expectedPresentTime);err updateActiveBuffer();err updateFrameNumber(latchTime);
接下来看下latchBuffer是在哪里调用的:
MessageQueue::Handler::handleMessagecompositor.commitSurfaceFlinger::commitlatchBuffers()for (const auto layer : mLayersWithQueuedFrames) {if (layer-latchBuffer(visibleRegions, latchTime, expectedPresentTime)) {mLayersPendingRefresh.push_back(layer);newDataLatched true;}layer-useSurfaceDamage();} 二. BufferStateLayer的GraphicBuffer怎么传递到hwc_layer中去的
这个我们要知道的是BufferStateLayer的GraphicBuffer最终传递到hwc_layer中是要经过OputputLayer的通过前面我们知道此时的GraphicBuffer存储在BufferInfo中如下:
class BufferLayer : public Layer {...struct BufferInfo {nsecs_t mDesiredPresentTime;std::shared_ptrFenceTime mFenceTime;spFence mFence;uint32_t mTransform{0};ui::Dataspace mDataspace{ui::Dataspace::UNKNOWN};Rect mCrop;uint32_t mScaleMode{NATIVE_WINDOW_SCALING_MODE_FREEZE};Region mSurfaceDamage;HdrMetadata mHdrMetadata;int mApi;PixelFormat mPixelFormat{PIXEL_FORMAT_NONE};bool mTransformToDisplayInverse{false};std::shared_ptrrenderengine::ExternalTexture mBuffer;//存放GraphicBufferuint64_t mFrameNumber;int mBufferSlot{BufferQueue::INVALID_BUFFER_SLOT};bool mFrameLatencyNeeded{false};}; BufferInfo mBufferInfo;...}我们先看怎么传递到OutputLayer的:
MessageQueue::Handler::handleMessage(...)compositor.composite(...)SurfaceFlinger::composite(...)mCompositionEngine-present(...)//CompositionEngine.cppupdateLayerStateFromFE(args)output-updateLayerStateFromFE(args)//Output.cppfor (auto* layer : getOutputLayersOrderedByZ()) {layer-getLayerFE().prepareCompositionState(args.updatingGeometryThisFrame ? LayerFE::StateSubset::GeometryAndContent: LayerFE::StateSubset::Content);} //frameworks/native/services/surfaceflinger/Layer.cppvoid Layer::prepareCompositionState(compositionengine::LayerFE::StateSubset subset) {using StateSubset compositionengine::LayerFE::StateSubset;switch (subset) {case StateSubset::BasicGeometry:prepareBasicGeometryCompositionState();break;case StateSubset::GeometryAndContent:prepareBasicGeometryCompositionState();prepareGeometryCompositionState();preparePerFrameCompositionState();//调用子类BufferLayer的break;case StateSubset::Content:preparePerFrameCompositionState();break;case StateSubset::Cursor:prepareCursorCompositionState();break;}
} //frameworks/native/services/surfaceflinger/BufferLayer.cpp
void BufferLayer::preparePerFrameCompositionState() {Layer::preparePerFrameCompositionState();...compositionState-buffer getBuffer();compositionState-bufferSlot (mBufferInfo.mBufferSlot BufferQueue::INVALID_BUFFER_SLOT)? 0: mBufferInfo.mBufferSlot;compositionState-acquireFence mBufferInfo.mFence;compositionState-frameNumber mBufferInfo.mFrameNumber;compositionState-sidebandStreamHasFrame false;
} 分析layer是否参与合成
最简单的SurfaceFlinger应用程序
Android14 SurfaceFlinger-BLASTBufferQueue的创建
Android 14 SurfaceFlinger-Layer visibleRegion的计算过程
SurfaceFlinger的commit/handleTransaction分析 这里重点关注各种State
