blink渲染知识12 - 硬件渲染之触发beginframe-优快云博客

本文链接：https://blog.youkuaiyun.com/csshell2002/article/details/48313759

本文深入探讨了Android系统中硬件渲染的过程，包括BeginMainFrame的触发、硬件渲染的调用栈以及不同场景下（如开启和关闭Tab）的渲染流程。详细解析了从ThreadProxy到SynchronousCompositor的各个关键步骤，揭示了硬件绘制如何与UI线程、合成器线程以及渲染线程协同工作，以实现高效流畅的图形渲染。

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ThreadProxy::BeginMainFrame会触发renderlayer tree中各layer的paint.那么谁触发的BeginMainFrame?

ThreadProxy::ScheduledActionSendBeginMainFrame

-> Proxy::MainThreadTaskRunner()->PostTask(

FROM_HERE,

base::Bind(&ThreadProxy::BeginMainFrame,

硬件渲染触发的callstack:

注意，下面的callstack来自4.3机子：

#0 cc::ThreadProxy::ScheduledActionSendBeginMainFrame(this=0x641def38) at ../../cc/trees/thread_proxy.cc:691

#1 0x6078da14 in cc::Scheduler::ProcessScheduledActions

//这里只是向webcore申请paint操作。

(this=this@entry=0x64993cb8) at../../cc/scheduler/scheduler.cc:665

#2 0x6078df92 in cc::Scheduler::BeginImplFrame

//此函数不光要向webcore线程发出申请一paint操作。还要自己构造合成一个frame.

(this=this@entry=0x64993cb8, args=...) at../../cc/scheduler/scheduler.cc:520

#3 0x6078e304 in cc::Scheduler::BeginFrame(this=0x64993cb8, args=...) at ../../cc/scheduler/scheduler.cc:426

#4 0x6079795e in cc::LayerTreeHostImpl::BeginFrame(this=<optimized out>, args=...) at../../cc/trees/layer_tree_host_impl.cc:1408

#5 0x60b97c16 incontent::SynchronousCompositorOutputSurface::InvokeComposite(this=this@entry=0x642f4868, transform=..., viewport=..., clip=...,viewport_rect_for_tile_priority=...,

transform_for_tile_priority=..., hardware_draw=<optimizedout>, hardware_draw@entry=true) at../../content/browser/android/in_process/synchronous_compositor_output_surface.cc:227

#6 0x60b97e5e incontent::SynchronousCompositorOutputSurface::DemandDrawHw(this=0x642f4868, surface_size=..., transform=..., viewport=...,clip=..., viewport_rect_for_tile_priority=...,

transform_for_tile_priority=...) at../../content/browser/android/in_process/synchronous_compositor_output_surface.cc:178

#7 0x60b977b0 in content::SynchronousCompositorImpl::DemandDrawHw

//这个是同步compositor.此函数就会返回一个compositorframe.

this=0x6498e6c0, surface_size=..., transform=..., viewport=...,clip=..., viewport_rect_for_tile_priority=...,transform_for_tile_priority=...)

at../../content/browser/android/in_process/synchronous_compositor_impl.cc:139

#8 0x607f6cf0 inandroid_webview::BrowserViewRenderer::OnDrawHardware

注意，这个函数被调用的前提是我们是4.3,4.4系统，因为这个系统上，ui线程会调用drawGl,所以可以让他调用BrowserViewRender来合成一个compositorframe. 在5.0系统上，应该又真正的ui线程去合成compositorframe,而不应该在drawGl执行时干这件事情。

BrowserViewRender据说就是处理webview相关的一切绘图操作的类。此函数会掉用browser的childcompositor合成出一份compositorframe并保存到draw_gl_input里面。供后续使用，后续先要commit他。

(this=this@entry=0x6498e540)at ../../android_webview/browser/browser_view_renderer.cc:304

#9 0x60e5a5f8 in android_webview::AwContents::DrawGL(this=0x6498e458, draw_info=0xbec91240) at../../android_webview/native/aw_contents.cc:429//这个是我们注册给系统的drawGL函数。在4.4,4.3上是ui线程调用，在androidL上是一个独立的系统的render线程调用。

#10 0x60f5e816 in draw_gl_normal(this=0x641ffeb0, data=<optimized out>, what=<optimizedout>) at../../third_party/android_plat_support/draw_gl_functor.cpp:139

#11 android::(anonymous namespace)::DrawGLFunctor::operator()(this=0x641ffeb0, what=<optimized out>, data=<optimizedout>) at../../third_party/android_plat_support/draw_gl_functor.cpp:60//怀疑这个函数被注册到系统，底层。

#12 0x40bf40b2 in ?? () from/tmp/tshao-adb-gdb-libs/system/lib/libhwui.so

#13 0x40be80b0 in ?? () from/tmp/tshao-adb-gdb-libs/system/lib/libhwui.so

#14 0x40be686c in ?? () from/tmp/tshao-adb-gdb-libs/system/lib/libhwui.so

#15 0x40be6798 in ?? () from/tmp/tshao-adb-gdb-libs/system/lib/libhwui.so

#16 0x40beee90 in ?? () from/tmp/tshao-adb-gdb-libs/system/lib/libhwui.so

#17 0x4024caf6 in ?? () from/tmp/tshao-adb-gdb-libs/system/lib/libandroid_runtime.so

#18 0x408dec50 in dvmPlatformInvoke () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#19 0x4090eed2 in dvmCallJNIMethod(unsigned int const*, JValue*,Method const*, Thread*) () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#20 0x408e8064 in dvmJitToInterpNoChain () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#21 0x408e8064 in dvmJitToInterpNoChain () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

关闭tab时，硬件渲染引发的callstack:

#0 cc::ThreadProxy::ScheduledActionSendBeginMainFrame(this=0x641def38) at ../../cc/trees/thread_proxy.cc:691

#1 0x6078da14 in cc::Scheduler::ProcessScheduledActions(this=0x64993cb8) at ../../cc/scheduler/scheduler.cc:665

#2 0x6078daca in cc::Scheduler::SetNeedsCommit (this=<optimizedout>) at ../../cc/scheduler/scheduler.cc:169

#3 0x607a2928 in cc::ThreadProxy::SetNeedsCommitOnImplThread(this=0x641def38) at ../../cc/trees/thread_proxy.cc:400

#4 0x6079ba64 in cc::LayerTreeHostImpl::ReleaseGL(this=0x64964948) at ../../cc/trees/layer_tree_host_impl.cc:2200

#5 0x6076a270 in cc::OutputSurface::ReleaseGL (this=<optimizedout>) at ../../cc/output/output_surface.cc:170

#6 0x60b97afe incontent::SynchronousCompositorOutputSurface::ReleaseHwDraw(this=<optimized out>) at../../content/browser/android/in_process/synchronous_compositor_output_surface.cc:157

#7 0x60b979c8 incontent::SynchronousCompositorImpl::ReleaseHwDraw (this=<optimizedout>) at../../content/browser/android/in_process/synchronous_compositor_impl.cc:114

#8 0x607f6682 inandroid_webview::BrowserViewRenderer::ReleaseHardware(this=this@entry=0x6498e540) at../../android_webview/browser/browser_view_renderer.cc:543

#9 0x60e5a82c inandroid_webview::AwContents::OnDetachedFromWindow (this=0x6498e458,env=<optimized out>, obj=<optimized out>) at../../android_webview/native/aw_contents.cc:956

#10 0x408dec50 in dvmPlatformInvoke () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#11 0x4090eed2 in dvmCallJNIMethod(unsigned int const*, JValue*,Method const*, Thread*) () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#12 0x409108be in dvmResolveNativeMethod(unsigned int const*,JValue*, Method const*, Thread*) () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#13 0x408e8064 in dvmJitToInterpNoChain () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#14 0x408e8064 in dvmJitToInterpNoChain () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

Backtrace stopped: previous frame identical to this frame (corruptstack?)

还可能出现的软件渲染触发的callstack:

#0 cc::ThreadProxy::ScheduledActionSendBeginMainFrame(this=0x641def38) at ../../cc/trees/thread_proxy.cc:691

#1 0x6078da14 in cc::Scheduler::ProcessScheduledActions(this=this@entry=0x64993cb8) at ../../cc/scheduler/scheduler.cc:665

#2 0x6078df92 in cc::Scheduler::BeginImplFrame(this=this@entry=0x64993cb8, args=...) at../../cc/scheduler/scheduler.cc:520

#3 0x6078e304 in cc::Scheduler::BeginFrame (this=0x64993cb8,args=...) at ../../cc/scheduler/scheduler.cc:426

#4 0x6079795e in cc::LayerTreeHostImpl::BeginFrame(this=<optimized out>, args=...) at../../cc/trees/layer_tree_host_impl.cc:1408

#5 0x60b97c16 incontent::SynchronousCompositorOutputSurface::InvokeComposite(this=this@entry=0x642f4868, transform=..., viewport=..., clip=...,viewport_rect_for_tile_priority=...,

transform_for_tile_priority=..., hardware_draw=<optimizedout>, hardware_draw@entry=false) at../../content/browser/android/in_process/synchronous_compositor_output_surface.cc:227

#6 0x60b97f28 incontent::SynchronousCompositorOutputSurface::DemandDrawSw(this=0x642f4868, canvas=<optimized out>) at../../content/browser/android/in_process/synchronous_compositor_output_surface.cc:202

#7 0x60b97800 in content::SynchronousCompositorImpl::DemandDrawSw(this=0x6498e6c0, canvas=<optimized out>) at../../content/browser/android/in_process/synchronous_compositor_impl.cc:155

#8 0x607f6a14 inandroid_webview::BrowserViewRenderer::CompositeSW(this=this@entry=0x6498e540, canvas=canvas@entry=0xbec912c8) at../../android_webview/browser/browser_view_renderer.cc:846

#9 0x607f7796 inandroid_webview::BrowserViewRenderer::ForceFakeCompositeSW(this=this@entry=0x6498e540) at../../android_webview/browser/browser_view_renderer.cc:840

#10 0x607f7914 inandroid_webview::BrowserViewRenderer::FallbackTickFired(this=0x6498e540) at../../android_webview/browser/browser_view_renderer.cc:826

#11 0x607f5afa in Run (object=<optimized out>,this=0xbec91420) at ../../base/bind_internal.h:134

#12 MakeItSo (a1=<optimized out>, runnable=...) at../../base/bind_internal.h:871

#13 base::internal::Invoker<1,base::internal::BindState<base::internal::RunnableAdapter<void(android_webview::BrowserViewRenderer::*)()>, void(android_webview::BrowserViewRenderer*), void (base::internal::Unret

ainedWrapper<android_webview::BrowserViewRenderer>)>,void(android_webview::BrowserViewRenderer*)>::Run(base::internal::BindStateBase*)(base=<optimized out>) at ../../base/bind_internal.h:1169

#14 0x6055cdf2 in Run (this=<optimized out>) at../../base/callback.h:401

#15 base::CancelableCallback<void ()>::Forward()(this=<optimized out>) at ../../base/cancelable_callback.h:106

#16 0x6055ce38 in Run (object=<optimized out>,this=0xbec91438) at ../../base/bind_internal.h:134

#17 MakeItSo (weak_ptr=..., runnable=...) at../../base/bind_internal.h:882

#18 base::internal::Invoker<1,base::internal::BindState<base::internal::RunnableAdapter<void(base::CancelableCallback<void ()>::*)()>, void(base::CancelableCallback<void ()>*), void(base::WeakPtr<base::Cancela

bleCallback<void ()> >)>, void(base::CancelableCallback<void()>*)>::Run(base::internal::BindStateBase*) (base=0x64215488)at ../../base/bind_internal.h:1169

#19 0x6100e280 in Run (this=0xbec91550) at../../base/callback.h:401

#20 base::MessageLoop::RunTask (this=this@entry=0x5c9415f8,pending_task=...) at ../../base/message_loop/message_loop.cc:464

#21 0x6100e338 in base::MessageLoop::DeferOrRunPendingTask(this=this@entry=0x5c9415f8, pending_task=...) at../../base/message_loop/message_loop.cc:482

#22 0x6100ebac in base::MessageLoop::DoDelayedWork(this=0x5c9415f8, next_delayed_work_time=0xbec91598) at../../base/message_loop/message_loop.cc:634

#23 0x60ff1b46 in DoRunLoopOnce(delayed_scheduled_time_ticks=34676111993, native_delegate=<optimizedout>, obj=0x4330001d, env=0x41f93cf0) at../../base/message_loop/message_pump_android.cc:60

#24Java_com_jetpack_dolphin_webkit_org_chromium_base_SystemMessageHandler_nativeDoRunLoopOnce(env=0x41f93cf0, jcaller=0x4330001d,messagePumpDelegateNative=<optimized out>,

delayedScheduledTimeTicks=34676111993) atgen/base/jni/SystemMessageHandler_jni.h:42

#25 0x408dec50 in dvmPlatformInvoke () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#26 0x4090eed2 in dvmCallJNIMethod(unsigned int const*, JValue*,Method const*, Thread*) () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#27 0x408e8064 in dvmJitToInterpNoChain () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#28 0x408e8064 in dvmJitToInterpNoChain () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

看看DrawGLFunctor的使用和调用。

Native层和java层都有DrawGLFunctor他们相互关联。

native的在third_party/android_plat_support目录下。

DrawGLFunctor.java类的requestDrawGL函数会将native的drawGL操作注册进系统，系统会在合适时间调用。

AwContents.java有函数requestDrawGL会被nativie调用。

->NativeGLDelegate接口的requestDrawGL函数,这个接口实际上是WebViewNativeGLDelegate。，定义在webviewchromium.java中

->建立DrawGLFunctor并调用DrawGLFunctor.requestDrawGL().

->delegate的函数，delegate是ProxyDelegate(Api21CompatibilityDelegate)

ProxyDelegate继承自webviewDelegate,并且他只是一个adapter,他含有真正的delegate,

Api21CompatibilityDelegate。Api21CompatibilityDelegate也继承自WebViewDelegate,并且定义在WebViewDelegateFactory.java里。

->WebViewDelegateFactory.java中Api21CompatibilityDelegate的：

@Override

public int callDrawGlFunction(Canvascanvas, long nativeDrawGLFunctor) {

try {

// DOLPHIN CHANGE BEGIN

if (mDetachFunctorMethod == null) return -1;

if (android.os.Build.VERSION.SDK_INT < 20) {

return(Integer)mCallDrawGLFunctionMethod.invoke(canvas,(int)nativeDrawGLFunctor);

}

// DOLPHIN CHANGE END

return(Integer)mCallDrawGLFunctionMethod.invoke(canvas,nativeDrawGLFunctor);//nativeDrawGLFunctor至此被传进入了系统内部。这样系统就会调用native的DrawGLFunctor。

} catch (Exception e) {

throw new RuntimeException("Invalid reflection",e);

}

或者

publicvoid invokeDrawGlFunctor(ViewcontainerView, long nativeDrawGLFunctor,

boolean waitForCompletion) {

try {

Object viewRootImpl =mGetViewRootImplMethod.invoke(containerView);

if (viewRootImpl != null &&mInvokeFunctorMethod != null) {

mInvokeFunctorMethod.invoke(viewRootImpl,nativeDrawGLFunctor,waitForCompletion);

}

} catch (Exception e) {

throw new RuntimeException("Invalid reflection",e);

}

上面的mCallDrawGLFunctionMethod可能是类android.view.HardwareCanvas的callDrawGLFunction成员，或者callDrawGLFunction2成员。

上面的mInvokeFunctorMethod可能是android.view.ViewRootImpl类的invokeFunctor成员。

那么awContents.cc的requestDrawGL函数被调用的stack；这里只是要求系统调用gl操作而发出一个申请。

#0 android_webview::AwContents::RequestDrawGL(this=0x5a7627a0,

canvas=0x70600021, wait_for_completion=false) at../../android_webview/native/aw_contents.cc:797

#1 0x61037086 in android_webview::BrowserViewRenderer::OnDraw

//这个函数要在childcompositor这边合成一个compositorframe, 此函数是ui线程执行。所以他可以合成compositorframe. 然后向系统注册申请下一个gl操作。

(this=this@entry=0x5a762888,java_canvas=java_canvas@entry=0x70600021,is_hardware_canvas=is_hardware_canvas@entry=true, scroll=...,

global_visible_rect=...) at../../android_webview/browser/browser_view_renderer.cc:239

#2 0x6169858e in android_webview::AwContents::OnDraw(this=0x5a7627a0, env=<optimized out>, obj=<optimized out>,canvas=0x70600021,is_hardware_accelerated=1'\001', scroll_x=0, scroll_y=0, visible_left=0,

visible_top=220, visible_right=720, visible_bottom=1184) at../../android_webview/native/aw_contents.cc:1058

#3 0x4092bc50 in dvmPlatformInvoke () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#4 0x4095bed2 in dvmCallJNIMethod(unsigned int const*, JValue*, Methodconst*, Thread*) () from /tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#5 0x4095d8be in dvmResolveNativeMethod(unsigned int const*, JValue*,Method const*, Thread*) () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#6 0x40935064 in dvmJitToInterpNoChain () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

#7 0x40935064 in dvmJitToInterpNoChain () from/tmp/tshao-adb-gdb-libs/system/lib/libdvm.so

下面的逻辑可能不正确

应该是来自java层的，下面是UI线程。

当native觉得网页内容有变化，会调用WebView的invalidate函数，告知系统，然后系统会调用onDraw到我们的view,然后我们会注册一个DrawGL到系统，并请求系统在合适的时候调用DrawGL,从而触发并推动一次渲染流水线开始work.

WebView.onDraw

->WebViewChromium.onDraw

AwContents.java,onDraw(canvas)

-----------native 在下面---------------

awContents.cc,onDraw

->BrowserViewRenderer::OnDraw

->AwContents::requestDrawGL，5.0新系统可能直接调用BrowserViewRenderer::OnDrawHardware来调用childcompositor合成一个compositorframe之后，才调用requestdraw gl

->Java_AwContents_requestDrawGL,

-----------------下面java层------------------

AwContents.java,requestDrawGL

->WebViewNativeGLDelegate.requestDrawGL

->WebViewDelegateFactory.java里callDrawGlFunction/invokeDrawGlFunctor。

将native的DrawGLFunctor注册进系统....并调用系统的drawGl.

这里是通过调用android.view.HardwareCanvas一个隐藏api的callDrawGLFunction方法，把我们的一个native的函数DrawGLFunctor传递进去给系统的。

注意，此时函数就会立即返回，并且能够返回一份canvas数据，这个canvas数据应该是之前的历史数据。

但同时，又向系统发送了一个请求绘制的申请。而系统会在合适的时候调用之前我们注册到系统里面的函数。

-------------------系统--------------下面是native---------

一定时间之后，系统调用我们注册的函数：注意，此时所处的线程和之前我们应用向系统发送绘制申请的线程是一个，都是ui线程。4.3上是这样的，但是androidL应该就是系统的render线程调用这个callback.

（注：HardwareCanvas允许客户端提供自己的GL回调函数，Android View系统在重放（playback）显示列表绘制View层次时会调用这个回调函数，在AndroidFramework内部实现中，当开始绘制HardwareCanvas时，当前GL上下文会绑定HardwareCanvas的framebuffer对象，所以GL回调函数中所有的GL命令实际上在操作HardwareCanvas的framebuffer对象）.那么在drawGl函数中，parentcompositor合成所有内容，并绘制到glcontext的话，就会绘制到framebuffer上。

->DrawGLFunctor::operator()

->draw_gl_normal, 系统提供了尺寸，clip等数据，还有mode.这个函数指针来自于WebViewChromiumFactoryProvider.java中的initPlatSupportLibrary()函数中的DrawGLFunctor.setChromiumAwDrawGLFunction(AwContents.getAwDrawGLFunction());。本质上来于AwContents.

->AwContents.cc中的DrawGLFunction()

->AwContents::DrawGL 该看这里了。

如果是4.4,4.3先调用BrowserViewRender::onDrawHardware，否则如果5.0就不需要再调用BrowserViewRender::onDrawHardware了，因为childcompositor的合成工作不再drawGL下执行。

创建HardwareRenderer，再调用HardwareRenderer::DrawGL.

注意，4.3/4.4上才会调用下面操作：

->BrowserViewRenderer::OnDrawHardware

->SynchronousCompositorImpl::DemandDrawHw

->SynchronousCompositorOutputSurface::DemandDrawHw

本函数除了调用下面的invokeComposite之外，还会返回一个compositorFrame，并把它设置到sharedRenderState的drawgl input里面。返回的这个frame应该是之前弄好的。并且来自于：voidSynchronousCompositorOutputSurface::SwapBuffers(frame）中的frame.

->:SynchronousCompositorOutputSurface::InvokeComposite

->cc::LayerTreeHostImpl::BeginFrame

->cc::Scheduler::BeginFrame

->cc::Scheduler::BeginImplFrame

推动statemachine

->cc::Scheduler::ProcessScheduledActions

->cc::ThreadProxy::ScheduledActionSendBeginMainFrame//这里schedule一个task,要求beginFrame,要求内核要开始绘制。当然是要把请求发给另外的线程。应该是webcore线程。

下面callstack是4.3/4.4上执行drawGL时，顺带执行了childconmpositor的合成并触发webcore线程的BeginFrame的callstack: