Performance regressions in NVDA with Windows Terminal

[Neurrone]

/CC @codeofdusk

Steps to reproduce:

Use Windows Terminal. In particular:

• Type in text
• Use vim to edit a text file and exit, or use git log - anything that clears the screen and switches back once the command finishes
• Use commands like git status

Basically normal use of the terminal

Actual behavior:

I've noticed that NVDA now lags noticeably:

• When typing characters into the prompt, there is now a very noticeable delay before key echo occurs
• When the screen clears such as when exiting editing of a text file with Vim, there is again a noticeable delay before NVDA starts reading text
• When using commands like git status and nvda+up arrow to read previous lines, NVDA seems to be "stuck" on the last line or two of output for a few seconds before nvda + up arrow is able to read previous lines of output beyond the last 2 lines.

Expected behavior:

None of this should be happening, unsure if it s aregression with NVDA or Terminal

NVDA logs, crash dumps and other attachments:

None

System configuration

NVDA installed/portable/running from source:

Installed

NVDA version:

alpha-26524,bc1f92f9 (2022.4.0.26524)

Windows version:

10.0.19044.2006

Name and version of other software in use when reproducing the issue:

Windows terminal 1.14.2281.0

Other information about your system:

Other questions

Does the issue still occur after restarting your computer?

Yes

Have you tried any other versions of NVDA? If so, please report their behaviors.

I have also seen this on another laptop which is on a more recent alpha build

If NVDA add-ons are disabled, is your problem still occurring?

Yes

Does the issue still occur after you run the COM Registration Fixing Tool in NVDA's tools menu?

[seanbudd]

@codeofdusk @carlos-zamora - any ideas on this one?

[Neurrone]

After a few weeks of usage, I haven't seen the first item occur often, maybe my computer was under high load or something.

I suspect that the second item happens when there is a lot of text already in the terminal although I'd need to test this more.

The third item where it gets stuck on the first couple of most recent lines for a while before you can read further above happens for me all the time and is something I can reliably reproduce.

[brunoprietog]

I can confirm this, especially when exiting vim

[seanbudd]

@brunoprietog, which version of NVDA are you using?

[brunoprietog]

NVDA alpha-27157,0fc81e9f

[tage64]

I have this annoying issue all the time, every day, and it is very frustrating. Specificly I have the "third" problem where moving the review cursor becomes slow after a massive flow of terminal output. It helps to restart the terminal and restart NVDA, but I have to do that every 30 minutes or so which is frustrating.

If anyone has any idea how to solve this issue or want to investigate this, I would be very thankful.

Best regards,
Tage

[Adriani90]

@Neurrone, @brunoprietog, @tage64 can you test please with the last alpha version of NVDA? The one which contains code from #14888? This might have fixed this issue.

[tage64]

Yes! The issue seem to be fixed in the latest alpha (alpha-30080,dd8a44cf)! Thanks alot!

[Neurrone]

@tage64 what version of NVDA and Windows terminal are you using?

I haven't seen this in a while, even without the code from #14888

[tage64]

I was using NVDA 2023.3 on Windows 11 version 22H2. I don't know how to check the terminal version but the computer was installed only a month ago so it shouldn't be too old.

[Adriani90]

Thanks for the update, closing as works for me.