Typed characters are mis-ordered when CPU usage is high

[Takashi Yano]

On Fri, 18 Mar 2022 13:23:35 +0900
Takashi Yano <takashi.yano@nifty.ne.jp> wrote:

> On Thu, 17 Mar 2022 20:40:15 +0200
> Orgad Shaneh wrote:
> > On Fri, Mar 11, 2022 at 11:36 PM Takashi Yano <takashi.yano@nifty.ne.jp> wrote:
> > > I looked into this problem and found the cause.
> > > This seems to be due to a bug of fsync(). Cygwin's fsync()
> > > flushes the console input buffer unlike linux.
> > >
> > > I will propose a patch for this issue.
> > >
> > > --
> > > Takashi Yano <takashi.yano@nifty.ne.jp>
> > 
> > Thank you very much. Looks better now.
> > 
> > I'm sorry for nudging, but on msys2 I still get frequent mistypes when
> > typing fast.
> > 
> > I (still) don't have a consistent reproduction, but if I get it
> > correctly, it looks like one or more characters I type right when the
> > prompt appears show up before the buffered characters.
> > 
> > For instance, I run git fetch, and while it is running I type git
> > status, *sometimes* 1-2 characters "pop" to the left, so I get
> > something like tgit satus.
> > 
> > I wasn't able to reproduce it with cygwin, but on msys2 (with cygwin
> > 3.3 branch merged in) it happens to me all the time :/
> 
> Thansk for the report.
> 
> I cloned the msys2-runtime repository from
> https://github.com/msys2/msys2-runtime
> and applied patches in cygwin-3_3-branch against msys2-3_3_4-release
> branch. The patches applied are listed in cygwin-3_3-branch-merged.log
> attached. A few patches, which are not actually in cygwin-3_3-branch,
> are also applied just for avoiding conflict easily.
> 
> However, I cannot reproduce your problem. Have you surely applied the
> following patches especially important for this issue?
> 
> Could you please also check if the code of cons_master_thread() in
> fhandler_console.cc exactly matches with cons_master_thread.cc attached?

I also tried merge-3.3 branch from
https://github.com/orgads/msys2-runtime-1 (perhaps it's your repository),
and confirmed it works without the issue. What is the difference?

I tried the following steps.

1) Start cmd.exe (command prompt).
2) Run \msys64\usr\bin\bash -l
3) cd msys2-runtime
4) git fetch
5) Quickly type "git status" before the shell prompt is shown.
6) Repeat 4) and 5) many times.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>