网站标题 逗号,新冠北京最新消息,手机文字生成链接,中国城市建设网网站Android下SF合成流程重学习之onMessageInvalidate 引言
虽然看了很多关于Android Graphics图形栈的文章和博客#xff0c;但是都没有形成自己的知识点。每次学习了#xff0c;仅仅是学习了而已#xff0c;没有形成自己的知识体系#xff0c;这次趁着有时间#xff0c;这次…Android下SF合成流程重学习之onMessageInvalidate 引言
虽然看了很多关于Android Graphics图形栈的文章和博客但是都没有形成自己的知识点。每次学习了仅仅是学习了而已没有形成自己的知识体系这次趁着有时间这次必须把这个事情干透彻了 本篇引用的代码主要是Android R的。 并且Android下Graphics图形栈牵涉的点太多了这篇博客我们着重分析SF合成流程重学习之onMessageInvalidate的处理流程 SurfaceFlinger layer之间的对应关系
先用一张图来看下各个部分之间layer的对应关系。接下来会根据这个图来解析是如何进行转换的,如下: 一. SF处理事务和处理Buffer
在SF的onMessageInvalidate主要是用来处理事物和处理相关Buffer的我们在下面的博客中详细分析 1.1 onMessageInvalidate
文件 frameworks/native/services/surfaceflinger/Surfaceflinger.cppvoid SurfaceFlinger::onMessageInvalidate(nsecs_t expectedVSyncTime) {ATRACE_CALL();const nsecs_t frameStart systemTime();// expectedVSyncTime 是vsync回调带过来的时间戳通过nextAnticipatedVSyncTimeFrom 计算得到if (expectedVSyncTime frameStart) {mExpectedPresentTime expectedVSyncTime;} else {mExpectedPresentTime mScheduler-getDispSyncExpectedPresentTime(frameStart);}// 存储上一帧的expectedVSyncTimeconst nsecs_t lastScheduledPresentTime mScheduledPresentTime;mScheduledPresentTime expectedVSyncTime;...// 根据上一帧的present fence判断当前这一帧是否pendingconst TracedOrdinalbool framePending {PrevFramePending,previousFramePending(graceTimeForPresentFenceMs)};// 若framePending 或者 上一帧present fence释放的时间 上一帧vsync计算的时间戳 vsync周期的一半// 则当前帧要丢掉DisplayStatInfo stats;mScheduler-getDisplayStatInfo(stats);const nsecs_t frameMissedSlop stats.vsyncPeriod / 2;const nsecs_t previousPresentTime previousFramePresentTime();const TracedOrdinalbool frameMissed {PrevFrameMissed,framePending ||(previousPresentTime 0 (lastScheduledPresentTime previousPresentTime - frameMissedSlop))};// 根据合成类型判断丢帧的类型const TracedOrdinalbool hwcFrameMissed {PrevHwcFrameMissed,mHadDeviceComposition frameMissed};const TracedOrdinalbool gpuFrameMissed {PrevGpuFrameMissed,mHadClientComposition frameMissed};...// 这部分涉及帧率切换先是通过performSetActiveConfig 将新的帧率给到hwc然后下一帧再更新sf这边的状态if (mSetActiveConfigPending) {if (framePending) {mEventQueue-invalidate();return;}// We received the present fence from the HWC, so we assume it successfully updated// the config, hence we update SF.mSetActiveConfigPending false;ON_MAIN_THREAD(setActiveConfigInternal());}
}// mPropagateBackpressure 可以通过adb shell setprop debug.sf.disable_backpressure x 来控制,表示系统是否允许丢帧// 若允许丢帧则skip这次刷帧if (framePending mPropagateBackpressure) {if ((hwcFrameMissed !gpuFrameMissed) || mPropagateBackpressureClientComposition) {signalLayerUpdate();return;}}....bool refreshNeeded;{ConditionalLockGuardstd::mutex lock(mTracingLock, mTracingEnabled);// 主要的逻辑在这两个函数简单理解为处理layer或者display的事务和layer的bufferrefreshNeeded handleMessageTransaction();refreshNeeded | handleMessageInvalidate();...}// 帧率切换SurfaceFlinger主线程执行ON_MAIN_THREAD(performSetActiveConfig());...// 若layer的事务有变化或者有新的buffer则触发refreshsignalRefresh();
}上述onMessageInvalidate概括来说其主要处理的事情如下:
判断当前帧是否丢掉handleMessageTransaction 处理layer或者display事务handleMessageInvalidate 处理应用queue过来的Buffer帧率切换触发刷新流程 1.2 handleMessageTransaction
文件 frameworks/native/services/surfaceflinger/Surfaceflinger.cppbool SurfaceFlinger::handleMessageTransaction() {ATRACE_CALL();// 获取当前的mTransactionFlagsmTransactionFlags 由setTransactionFlags 赋值比如CreateLayer时会给mTransactionFlags 赋值eTransactionNeeded// createDisplay 时会给mTransactionFlags 赋值 eDisplayTransactionNeededuint32_t transactionFlags peekTransactionFlags();// flushTransactionQueues 会消费transactionQueuetransactionQueue 是上层通过SurfaceComposerClient 设的然后再通过binder设置给sf这边// setDisplayStateLocked 处理display的事务// setClientStateLocked 处理layer的事务// 这两部分事务都存放在surfaceflinger的mCurrentState 里面bool flushedATransaction flushTransactionQueues();// 有新的事务则要执行handleTransactionbool runHandleTransaction (transactionFlags (transactionFlags ! eTransactionFlushNeeded)) ||flushedATransaction ||mForceTraversal;// 处理layer和display的事务if (runHandleTransaction) {handleTransaction(eTransactionMask);} else {getTransactionFlags(eTransactionFlushNeeded);}if (transactionFlushNeeded()) {setTransactionFlags(eTransactionFlushNeeded);}return runHandleTransaction;
}//来看下display和layer有哪些事务处理文件 frameworks/native/services/surfaceflinger/Surfaceflinger.cpp// display的事务包括display Surface, layerStack , Projection , viewport, Size发生变化时附上eDisplayTransactionNeeded 这个flags
uint32_t SurfaceFlinger::setDisplayStateLocked(const DisplayState s) {const ssize_t index mCurrentState.displays.indexOfKey(s.token);if (index 0) return 0;uint32_t flags 0;DisplayDeviceState state mCurrentState.displays.editValueAt(index);const uint32_t what s.what;if (what DisplayState::eSurfaceChanged) {if (IInterface::asBinder(state.surface) ! IInterface::asBinder(s.surface)) {state.surface s.surface;flags | eDisplayTransactionNeeded;}}if (what DisplayState::eLayerStackChanged) {if (state.layerStack ! s.layerStack) {state.layerStack s.layerStack;flags | eDisplayTransactionNeeded;}}if (what DisplayState::eDisplayProjectionChanged) {if (state.orientation ! s.orientation) {state.orientation s.orientation;flags | eDisplayTransactionNeeded;}if (state.frame ! s.frame) {state.frame s.frame;flags | eDisplayTransactionNeeded;}if (state.viewport ! s.viewport) {state.viewport s.viewport;flags | eDisplayTransactionNeeded;}}if (what DisplayState::eDisplaySizeChanged) {if (state.width ! s.width) {state.width s.width;flags | eDisplayTransactionNeeded;}if (state.height ! s.height) {state.height s.height;flags | eDisplayTransactionNeeded;}}return flags;
}文件 frameworks/native/services/surfaceflinger/Surfaceflinger.cpp// layer的事务包括ePositionChanged, eLayerChanged, eAlphaChanged 等等跟上层的surface设置一样同样的事务同步给layer
uint32_t SurfaceFlinger::setClientStateLocked(const ComposerState composerState, int64_t desiredPresentTime, int64_t postTime,bool privileged,std::unordered_setListenerCallbacks, ListenerCallbacksHash listenerCallbacks) {
... spLayer layer nullptr;if (s.surface) {layer fromHandleLocked(s.surface).promote();...if (what layer_state_t::eDeferTransaction_legacy) {layer-pushPendingState();}// Only set by BLAST adapter layersif (what layer_state_t::eProducerDisconnect) {layer-onDisconnect();}if (what layer_state_t::ePositionChanged) {if (layer-setPosition(s.x, s.y)) {flags | eTraversalNeeded;}}
...
}
通过setDisplayStateLocked 和 setClientStateLocked 获取了display和layer的事务变化的flag并且setClientStateLocked还将layer与surface进行了事务的同步。
文件 frameworks/native/services/surfaceflinger/Surfaceflinger.cppvoid SurfaceFlinger::handleTransactionLocked(uint32_t transactionFlags)
{...if ((transactionFlags eTraversalNeeded) || mForceTraversal) {mForceTraversal false;// 遍历mCurrentState 里面的layer对有事务变化的layer进行处理doTransaction 主要的处理逻辑是对sync ponit的处理// sync ponit用于延迟显示的一些layer根据FrameNumber进行同步如果当前帧数达到了设定值latchBuffer就可以消费这个layermCurrentState.traverse([](Layer* layer) {uint32_t trFlags layer-getTransactionFlags(eTransactionNeeded);if (!trFlags) return;const uint32_t flags layer-doTransaction(0);if (flags Layer::eVisibleRegion)mVisibleRegionsDirty true;if (flags Layer::eInputInfoChanged) {mInputInfoChanged true;}});}// 处理 display的 事务逻辑if (transactionFlags eDisplayTransactionNeeded) {processDisplayChangesLocked();processDisplayHotplugEventsLocked();}...// SurfaceFlinger维持mCurrentState 和 mDrawingState 两个状态是个大的结构体mCurrentState 可以理解为下一帧的// layer和display的状态 mDrawingState 可以理解为当前帧的状态commitTransaction 将 mCurrentState 更新到这一帧的状态commitTransaction();
}handleMessageTransaction主要的作用是处理display和layer的事物将上层的surface和底层的layer属性做个同步涉及到很多的细节以后遇到具体场景来分析最后将mCurrentState 赋给 mDrawingState 更新到当前这一帧的状态。 1.3 handleMessageInvalidate
我们接着继续往下看累啊学习搞起来~
文件frameworks/native/services/surfaceflinger/Surfaceflinger.cppbool SurfaceFlinger::handleMessageInvalidate() {ATRACE_CALL();// 处理queue过来的Bufferbool refreshNeeded handlePageFlip();if (mVisibleRegionsDirty) {// 如果可见区域有变化则重新计算layer的范围computeLayerBounds();}//判断需要刷新的layer是否属于当前Outputfor (auto layer : mLayersPendingRefresh) {Region visibleReg;visibleReg.set(layer-getScreenBounds());invalidateLayerStack(layer, visibleReg);}mLayersPendingRefresh.clear();return refreshNeeded;
}bool SurfaceFlinger::handlePageFlip()
{...// 遍历 mDrawingState里面的layer判断该layer是否可在当前vsync内显示如果queueBuffer带过来的时间戳大于Vsync的时间戳则表示该layer不能在当前vsync内显示// 能够显示的layer放到mLayersWithQueuedFrames 里面mDrawingState.traverse([](Layer* layer) {if (layer-hasReadyFrame()) {frameQueued true;if (layer-shouldPresentNow(expectedPresentTime)) {mLayersWithQueuedFrames.push_back(layer);} else {ATRACE_NAME(!layer-shouldPresentNow());layer-useEmptyDamage();}} else {layer-useEmptyDamage();}});...// 遍历mLayersWithQueuedFrames 里面的layer执行latchBuffer在latchBuffer里面消费Buffer// 成功消费的layer放到mLayersPendingRefresh 里面for (auto layer : mLayersWithQueuedFrames) {if (layer-latchBuffer(visibleRegions, latchTime, expectedPresentTime)) {mLayersPendingRefresh.push_back(layer);}layer-useSurfaceDamage();if (layer-isBufferLatched()) {newDataLatched true;}...// 当有需要消费Buffer的layer则返回truereturn !mLayersWithQueuedFrames.empty() newDataLatched;文件 frameworks/native/services/surfaceflinger/BufferLayer.cppbool BufferLayer::latchBuffer(bool recomputeVisibleRegions, nsecs_t latchTime,nsecs_t expectedPresentTime) {...// 执行顺序BufferQueueLayer- updateTexImage BufferLayerConsumer- updateTexImage,具体逻辑在// BufferLayerConsumer 里面status_t err updateTexImage(recomputeVisibleRegions, latchTime, expectedPresentTime);// 更新mBufferInfo里的buffer这个变量是在BufferQueueLayer里面维护err updateActiveBuffer();if (err ! NO_ERROR) {return false;}//更新mBufferInfo的FrameNumbererr updateFrameNumber(latchTime);if (err ! NO_ERROR) {return false;}// 更新到mBufferInfogatherBufferInfo();...
}文件 frameworks/native/services/surfaceflinger/BufferLayerConsumer.cppstatus_t BufferLayerConsumer::updateTexImage(BufferRejecter* rejecter, nsecs_t expectedPresentTime,bool* autoRefresh, bool* queuedBuffer,uint64_t maxFrameNumber) {...BufferItem item;// acquireBuffer消费queue过来的Buffer,放到item里面status_t err acquireBufferLocked(item, expectedPresentTime, maxFrameNumber);...// 更新BufferLayerConsumer 状态都是从queueBuffer设置而来err updateAndReleaseLocked(item, mPendingRelease);...
}status_t BufferLayerConsumer::acquireBufferLocked(BufferItem* item, nsecs_t presentWhen,uint64_t maxFrameNumber) {status_t err ConsumerBase::acquireBufferLocked(item, presentWhen, maxFrameNumber);...if (item-mGraphicBuffer ! nullptr) {std::lock_guardstd::mutex lock(mImagesMutex);if (mImages[item-mSlot] nullptr || mImages[item-mSlot]-graphicBuffer() nullptr ||mImages[item-mSlot]-graphicBuffer()-getId() ! item-mGraphicBuffer-getId()) {// 将acquire出来的Buffer做成EGLImage为了后面GPU合成mImages[item-mSlot] std::make_sharedImage(item-mGraphicBuffer, mRE);}}return NO_ERROR;
}文件 frameworks/native/libs/gui/ConsumerBase.cppstatus_t ConsumerBase::acquireBufferLocked(BufferItem *item,nsecs_t presentWhen, uint64_t maxFrameNumber) {...// 实现在BufferQueueConsumer的 acquireBufferstatus_t err mConsumer-acquireBuffer(item, presentWhen, maxFrameNumber);if (err ! NO_ERROR) {return err;}if (item-mGraphicBuffer ! nullptr) {if (mSlots[item-mSlot].mGraphicBuffer ! nullptr) {freeBufferLocked(item-mSlot);}//更新Bufferslot里面的GraphicsBuffer这个Buffer的owner是GPU在处理mSlots[item-mSlot].mGraphicBuffer item-mGraphicBuffer;}// 更新Bufferslot里面的frameNumber和fence与queueBuffer设置保持一致这里的fence为acquireFencemSlots[item-mSlot].mFrameNumber item-mFrameNumber;mSlots[item-mSlot].mFence item-mFence;CB_LOGV(acquireBufferLocked: - slot%d/% PRIu64,item-mSlot, item-mFrameNumber);return OK;
}文件 frameworks/native/libs/gui/BufferQueueConsumer.cpp//跳过一些特殊情况代码细节把主线code拎出来分析
status_t BufferQueueConsumer::acquireBuffer(BufferItem* outBuffer,nsecs_t expectedPresent, uint64_t maxFrameNumber) {...// queueBuffer时入的队列BufferQueueCore::Fifo::iterator front(mCore-mQueue.begin());...// 拿到queueBuffer对应的slot和BufferItemslot front-mSlot;*outBuffer *front;...if (!outBuffer-mIsStale) {mSlots[slot].mAcquireCalled true;// Dont decrease the queue count if the BufferItem wasnt// previously in the queue. This happens in shared buffer mode when// the queue is empty and the BufferItem is created above.if (mCore-mQueue.empty()) {mSlots[slot].mBufferState.acquireNotInQueue();} else {// 更新状态为acquiremSlots[slot].mBufferState.acquire();}// queueBuffer入队acquireBuffer出队mCore-mQueue.erase(front);...
}handleMessageInvalidate主要作用是执行 latchBuffer 去 acquire 应用queue过来的Buffer然后拿到queueBuffer时设的Bufferslot一些状态属性给到BufferQueueLayer的mBufferInfo同时还把这个Buffer做成EGLImage为后面的GPU合成做准备期间都是数据之间的传递所以说SurfaceFlinger并未真正触碰Buffer的内容。 写在最后
好了今天的博客Android下SF合成流程重学习之onMessageInvalidate就到这里了。总之青山不改绿水长流先到这里了。如果本博客对你有所帮助麻烦关注或者点个赞如果觉得很烂也可以踩一脚谢谢各位了
