[Bug 56233] New: On macOS Sonoma, applications respond slowly when caps lock is enabled

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56233

Bug ID: 56233
           Summary: On macOS Sonoma, applications respond slowly when caps
                    lock is enabled
           Product: Wine
           Version: 9.0
          Hardware: x86-64
                OS: MacOS
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: winemac.drv
          Assignee: [e-mail]
          Reporter: [e-mail]

macOS Sonoma introduces new "accessories" that appear below the text insertion
point, like a caps lock indicator or an input language switcher (see [1]).
These also show up in Wine windows, since they use existing APIs like
NSTextInputClient to discover whether an insertion point is present and where
in the view it's located.

But, when an accessory like the caps lock indicator is displayed, interacting
with the window (say, pulling down menus) is extremely slow. There are
half-second pauses when displaying/hiding menus or other windows. This can be
easily reproduced using notepad.

I ran sample during the slowdown and was able to see the problem. Here's the
backtrace, with some unimportant lines removed:

3294 __OnMainThread_block_invoke  (in winemac.so) + 16  [0x20b56ac10] 
cocoa_event.m:507
3070 __macdrv_set_cocoa_window_frame_block_invoke  (in winemac.so) + 100 
[0x20b577dd4]  cocoa_window.m:3464
3070 -[WineWindow setFrameFromWine:]  (in winemac.so) + 557  [0x20b57258d] 
cocoa_window.m:2012
3070 -[WineWindow setFrameAndWineFrame:]  (in winemac.so) + 60  [0x20b5721dc] 
cocoa_window.m:1938
3069 -[WineWindow setFrame:display:]  (in winemac.so) + 136  [0x20b575008] 
cocoa_window.m:2682
...
3066 -[WineWindow windowDidResize:skipSizeMove:]  (in winemac.so) + 441 
[0x20b5762d9]  cocoa_window.m:3031
3066 -[TUINSCursorUIController invalidateCharacterCoordinates]  (in
TextInputUIMacHelper) + 113  [0x7ffc12ad733a]
...
1643 -[WineContentView firstRectForCharacterRange:actualRange:]  (in
winemac.so) + 196  [0x20b56ef24]  cocoa_window.m:926
1643 -[WineEventQueue query:timeout:flags:]  (in winemac.so) + 217 
[0x20b56a209]  cocoa_event.m:336
1643 -[WineApplicationController waitUntilQueryDone:timeout:processEvents:] 
(in winemac.so) + 224  [0x20b55eb70]  cocoa_app.m:350

Pulling menus down creates new HWNDs, I think initially with 1x1 size, and then
the frame is set. This triggers windowDidResize, which calls [[[self
contentView] inputContext] invalidateCharacterCoordinates]. This is sensible,
character coordinates might change when the window is resized. And when caps
lock is enabled, the system then immediately calls
firstRectForCharacterRange:actualRange: to refresh the character coordinates.
This triggers a Wine QUERY_IME_CHAR_RECT query. The problem is that the thread
that would answer the query is currently in OnMainThread(), things deadlock and
the query times out after 300 ms. I think it's called twice, that's how you get
600 ms.

The twist is that OnMainThread() does service queries while waiting, except for
QUERY_IME_CHAR_RECT, because of a 2016 bug with Japanese input in Excel
2003/2007/2010. If you undo 33610da6b4f5d9ad052173f005fdb735dc471445 so that
QUERY_IME_CHAR_RECT is handled normally, the timeout goes away and things work
normally.

This needs to be fixed, my first thought is that maybe there have been changes
in the IME system since 2016 so that the special-case for QUERY_IME_CHAR_RECT
is no longer needed? A first step is to revert the 2016 fix and see if the
Excel bug can still be reproduced.

[1]:
https://developer.apple.com/documentation/appkit/text_display/adopting_the_s...