I have a WPF application that is constantly animating. One interaction (mouseup) and animation, in particular, delay the flow of the user interface long enough to be very noticeable.
Concurrency Visualizer shows that my UI thread is blocked for 300-500 ms. It also shows the stack when it is locked, and the lock stack:
The main thread stack in standby mode :
Category = Synchronization
Delay = 495.2472 ms
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
Unlock Stack:
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
The main thread is waiting for a background thread. This background thread does a few things, but this stack takes ~ 3/4 of the time:
:
= I/O
= 347,5122
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
, SyncFlush() MilCore , , ( Ray Burns).
, , WPF , WPF.