|
|
Rank: Advanced Member
Groups: Member
Joined: 3/10/2020
Posts: 59
|
We are using EO webbrowser in a WPF based desktop application.
We are experiencing slowness issue within our application for a short span of time and we are working with Microsoft to troubleshoot the same. On analyzing we found the slowness is with UIA/Accessibility COM objects getting created (on receiving WM_GETOBJECTS message) and perform eager cleanup intermitently. Every time CLR performs eager cleanup of UIA/Accessibility COM objects, it slows down the application.
We continued our analysis to detect the souce application which posts WM_GETOBJECTS message.
On looking at the kernel dump we found eowp.exe calls SetWinEventHook (callstack below) which (as per Microsoft) tells Windows OS that eowp.exe is looking for the range of "events" so that it can do something with them. We are checking if these "events" would be the ones which WPF application would see as UIA/Accessibility which would spin up AutomationPeers (UIA/Accessibility COM objects).
To confirm the same, can you please provide us more insight on how eowp calls "SetWinEventHook" and the purpose of having such hooks.
1: kd> x win32kbase!gpWinEventHooks
fffff3ab`21373e18 win32kbase!gpWinEventHooks = 0xfffff3d0`429f4bc0
1: kd> dx -r1 ((win32kbase!tagEVENTHOOK *)0xfffff3d0429f4bc0)
((win32kbase!tagEVENTHOOK *)0xfffff3d0429f4bc0) : 0xfffff3d0429f4bc0 [Type: tagEVENTHOOK *]
[+0x000] head [Type: _THROBJHEAD]
[+0x018] pehNext : 0xfffff3d0429f4920 [Type: tagEVENTHOOK *]
[+0x020] eventMin : 0x80000004 [Type: unsigned int]
[+0x024] eventMax : 0x80000005 [Type: unsigned int]
[+0x028 ( 0: 0)] fDestroyed : 0x0 [Type: unsigned int]
[+0x028 ( 1: 1)] fIgnoreOwnThread : 0x0 [Type: unsigned int]
[+0x028 ( 2: 2)] fIgnoreOwnProcess : 0x0 [Type: unsigned int]
[+0x028 ( 3: 3)] fSync : 0x1 [Type: unsigned int]
[+0x028 ( 4: 4)] fSkipWowCrossContext : 0x0 [Type: unsigned int]
[+0x030] hEventProcess : 0x2484 [Type: void *]
[+0x038] idEventThread : 0xbcc [Type: unsigned long]
[+0x040] offPfn : 0x2c760 [Type: unsigned __int64]
[+0x048] ihmod : 2 [Type: int]
[+0x050] pwszModulePath : 0x0 [Type: wchar_t *]
[+0x058] dpiContext : 0x6010 [Type: unsigned long]
|
|
Rank: Administration
Groups: Administration
Joined: 5/27/2007
Posts: 24,217
|
Hi, eowp.exe is used to run the Chromium browser engine. We looked into Chromium browser engine's source code and see that it does call SetWinEventHook at various location, and this one does seem to be related to accessiblity: https://source.chromium.org/chromium/chromium/src/+/main:ui/accessibility/platform/inspect/ax_event_recorder_win.cc?q=SetWinEventHook&ss=chromium We were not able to construct a scenario where it would be called in order to verify it. Do you know when SetWinEventHook is called? Thanks!
|
|
Rank: Advanced Member
Groups: Member
Joined: 3/10/2020
Posts: 59
|
We are hoping that you would let know a scenario in which the API is invoked from eowp.exe.
Our understanding is that this is invoked for the first time we create EO Webbrowser instance.
Can you please provide us a way (property or something) that would stop eowp.exe from calling "SetWinEventHook" as this has adverse effect on wpf applications.
|
|
Rank: Administration
Groups: Administration
Joined: 5/27/2007
Posts: 24,217
|
We did not find any instance where SetWinEventHook is called at all in our test einvironment. :( We only see it in the source code.
|
|