[PATCH v2] Cygwin: pty: Revise code waiting for forwarding again.

[Koichi Murase]

> On Jan 23 13:30, Takashi Yano wrote:
> > - After commit 6cc299f0e20e4b76f7dbab5ea8c296ffa4859b62, outputs of
> >   cygwin programs which call both printf() and WriteConsole() are
> >   frequently distorted. This patch reverts waiting function to dumb
> >   Sleep().

    Hi, I have a question related to this patch. (When I have a
question on a specific patch like this, which mailing list should I
come?  If I should not make a reply to the original cygwin-patch
mailing list, let me apologize in advance.  If so, I'll move to
cygwin mailing list.)

    When I try to use the recent commit 6d79e0a58 (tag: newlib-3.3.0),
any Cygwin program fails to start leaving the following message:

      0 [main] XXXX (YYYY) shared_info::initialize: size of shared
      memory region changed from 50104 to 49080

where XXXX and YYYY are the program name and PID.  I also tried with
the current master branch 8f502bd33, and the result was the same.  I
tested each commit one by one, and found that this problem is caused
after this patch:

  6cc299f0e - (2 days ago) Cygwin: pty: Revise code waiting for
  forwarding by master_fwd_thread. - Takashi Yano

In fact, if I drop this commit from the master branch, the problem
disappears.


    But, as there are no related reports here, I suspect this is the
problem specific to my environment.  In particular, I suspect that
this is caused by the compatibility of different versions of
`cygwin1.dll'.  Currently, when I try to use the new `cygwin1.dll', I
just replace `C:\cygwin64\bin\cygwin1.dll' with the version I built
from recent a commit (`new-cygwin1.dll') following the instruction for
snapshots which is found at

  https://cygwin.com/faq.html#faq.setup.snapshots

Here my question is, if this is caused by the way I try the new
version, what is the correct way to try the latest version built from
a commit in the git repository (do I need to rebuild all the
toolchain)?  Or, is this problem caused by other conditions?  I would
appreciate it if you could provide me some hints.


    Here is some trials in command prompt:

  C:\cygwin64\bin>bash
        0 [main] bash (18936) shared_info::initialize: size of shared
  memory region changed from 50104 to 49080

  C:\cygwin64\bin>dash
        0 [main] dash (7900) shared_info::initialize: size of shared
  memory region changed from 50104 to 49080

  C:\cygwin64\bin>stty
        0 [main] stty (2920) shared_info::initialize: size of shared
  memory region changed from 50104 to 49080

  C:\cygwin64\bin>cat
        0 [main] cat (21340) shared_info::initialize: size of shared
  memory region changed from 50104 to 49080

  C:\cygwin64\bin>mintty

mintty fails without any messages.


Thank you,

Koichi