wpf - 当mouseup事件触发动画时，WPF UI线程会暂时卡住

Question

我有一个不断动画的WPF应用程序。特别是一次交互(鼠标移动)和动画似乎将UI线程冻结了足够长的时间，从而非常引人注目。

并发可视化工具向我显示我的UI线程被阻止300-500ms。它还显示了处于阻塞状态的堆栈和未阻塞的堆栈:

冻结时的主线程堆栈:
类别=同步
延迟= 495.2472毫秒

ntoskrnl.exe!SwapContext_PatchXRstor
ntoskrnl.exe!KiSwapContext
ntoskrnl.exe!KiCommitThreadWait
ntoskrnl.exe!KeWaitForSingleObject
ntoskrnl.exe!NtWaitForSingleObject
ntoskrnl.exe!KiSystemServiceCopyEnd
ntdll.dll!NtWaitForSingleObject
kernelbase.dll!WaitForSingleObjectEx
wpfgfx_v0400.dll!CMilConnection::SynchronizeChannel
wpfgfx_v0400.dll!CMilChannel::SyncFlush
wpfgfx_v0400.dll!MilComposition_SyncFlush
clr.dll!DoNDirectCallWorker
presentationcore.dll!System.Windows.Media.Composition.DUCE+Channel.**SyncFlush**
presentationcore.dll!System.Windows.Media.MediaContext.NotifyChannelMessage
presentationcore.dll!System.Windows.Media.MediaContextNotificationWindow.MessageFilter
windowsbase.dll!MS.Win32.HwndWrapper.WndProc
windowsbase.dll!MS.Win32.HwndSubclass.DispatcherCallbackOperation
windowsbase.dll!System.Windows.Threading.ExceptionWrapper.InternalRealCall
windowsbase.dll!MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen
windowsbase.dll!System.Windows.Threading.Dispatcher.WrappedInvoke
windowsbase.dll!System.Windows.Threading.Dispatcher.InvokeImpl
windowsbase.dll!MS.Win32.HwndSubclass.SubclassWndProc
windowsbase.dll!dynamicClass.IL_STUB_ReversePInvoke
clr.dll!UMThunkStubAMD64
user32.dll!UserCallWinProcCheckWow
user32.dll!DispatchMessageWorker
clr.dll!DoNDirectCall__PatchGetThreadCall
windowsbase.dll!dynamicClass.IL_STUB_PInvoke
windowsbase.dll!System.Windows.Threading.Dispatcher.PushFrameImpl
presentationframework.dll!System.Windows.Application.RunInternal
presentationframework.dll!System.Windows.Application.Run
xqstream.windows.exe!IQ.IR.Stream.WPF.App.Main

取消阻止堆栈:

ntoskrnl.exe! ?? ?? ::FNODOBFM::`string'
ntoskrnl.exe!NtSetEvent
ntoskrnl.exe!KiSystemServiceCopyEnd
ntdll.dll!ZwSetEvent
kernelbase.dll!SetEvent
wpfgfx_v0400.dll!CMilConnection::PostMessageToClient
wpfgfx_v0400.dll!CMilServerChannel::SignalFinishedFlush
wpfgfx_v0400.dll!CComposition::FlushChannels
wpfgfx_v0400.dll!CPartitionThread::RenderPartition
wpfgfx_v0400.dll!CPartitionThread::Run
wpfgfx_v0400.dll!CPartitionThread::ThreadMain

主线程正在等待后台线程。后台线程正在做很多事情，但是这个堆栈占用了大约3/4的时间:

阻塞线程的最大任务:
类别= I/O
延迟= 347.5122毫秒

ntoskrnl.exe!SwapContext_PatchXRstor
ntoskrnl.exe!KiSwapContext
ntoskrnl.exe!KiCommitThreadWait
ntoskrnl.exe!KeWaitForSingleObject
dxgmms1.sys!VIDMM_GLOBAL::CloseOneAllocation
dxgmms1.sys!VidMmCloseAllocation
dxgkrnl.sys!DXGDEVICE::DestroyAllocations
dxgkrnl.sys!DXGDEVICE::ProcessTerminationList
dxgkrnl.sys!DXGDEVICE::TerminateAllocations
dxgkrnl.sys!DXGDEVICE::DestroyAllocation
dxgkrnl.sys!DxgkDestroyAllocation
win32k.sys!NtGdiDdDDIDestroyAllocation
ntoskrnl.exe!KiSystemServiceCopyEnd
gdi32.dll!ZwGdiDdDDIDestroyAllocation
d3d9.dll!DeallocateCB
dlumd64.dll![dlumd64.dll]
nvd3dumx.dll![nvd3dumx.dll]
nvd3dumx.dll![nvd3dumx.dll]
nvd3dumx.dll![nvd3dumx.dll]
nvd3dumx.dll![nvd3dumx.dll]
nvd3dumx.dll![nvd3dumx.dll]
nvd3dumx.dll![nvd3dumx.dll]
nvd3dumx.dll![nvd3dumx.dll]
nvd3dumx.dll![nvd3dumx.dll]
dlumd64.dll![dlumd64.dll]
dlumd64.dll![dlumd64.dll]
d3d9.dll!DdBltLH
d3d9.dll!CSwapChain::PresentMain
d3d9.dll!CSwapChain::Present
wpfgfx_v0400.dll!CD3DDeviceLevel1::PresentWithD3D
wpfgfx_v0400.dll!CD3DDeviceLevel1::Present
wpfgfx_v0400.dll!CHwDisplayRenderTarget::PresentInternal
wpfgfx_v0400.dll!CHwDisplayRenderTarget::Present
wpfgfx_v0400.dll!CHwHWNDRenderTarget::Present
wpfgfx_v0400.dll!CDesktopRenderTarget::Present
wpfgfx_v0400.dll!CDesktopHWNDRenderTarget::Present
wpfgfx_v0400.dll!CSlaveHWndRenderTarget::Present
wpfgfx_v0400.dll!CRenderTargetManager::Present
wpfgfx_v0400.dll!CComposition::Present
wpfgfx_v0400.dll!CPartitionThread::PresentPartition
wpfgfx_v0400.dll!CPartitionThread::Run
wpfgfx_v0400.dll!CPartitionThread::ThreadMain

我读过SyncFlush()是在几个MilCore函数之后调用的，它似乎会导致立即处理已发送的更改(贷给Ray Burns)。

我想摆脱这种冻结，但是我也希望对WPF在这种情况下正在做的事情有更好的了解，以便为WPF的工作方式建立更好的思维模型。

Answer 1

从来回堆栈的痕迹可以明显看出，主线程正在等待完全刷新的内容。我不知道什么是SyncFlush或如何解决它。

查看长时间的IO堆栈跟踪，问题可能出在Nvidia驱动程序上。 WPF(wpfgfx_v0400)正在调用DirectX 9(d3d9)，后者正在调用Nvidia驱动程序(nvd3dumx)。

现在，所有平台都有可能表现适当，并且正在执行您的代码告诉他们要做的事情。 WPF，DirectX 9或Nvidia驱动程序中也可能存在错误。大多数情况下，尽管问题与调用代码有关。

我假设此应用程序为鼠标向上事件处理程序。如果是这样，请查看正在执行的操作(或它如何干扰动画)将是性能问题的最可能根源。