[PATCH v2] Cygwin: dtable: Delete old kludge code for /dev/tty.

[PATCH v2] Cygwin: dtable: Delete old kludge code for /dev/tty.

[Takashi Yano]

This old kludge code assigns fhandler_console for /dev/tty even
if the CTTY is not a console when stat() has been called. Due to
this, the problem reported in
https://cygwin.com/pipermail/cygwin/2023-June/253888.html
occurs after the commit 3721a756b0d8 ("Cygwin: console: Make the
console accessible from other terminals.").

This patch fixes the issue by dropping the old kludge code.

Though the exact reason why the kludge code was necessary is not
clear enough, this kluge code has no longer seemed to be necessary
after the commit 6ae28c22639d. This is because even when /dev/tty
is not opened, /dev/tty became able to be refered via last_tty_dev,
which was introduced by the commit 6ae28c22639d.

Fixes: 23771fa1f7028 ("dtable.cc (fh_alloc): Make different decisions
  when generating fhandler for not-opened devices. Add kludge to deal
  with opening /dev/tty.")
Reported-by: Bruce Jerrick <bmj001@gmail.com>
Reviewed-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
---
 winsup/cygwin/dtable.cc | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/winsup/cygwin/dtable.cc b/winsup/cygwin/dtable.cc
index 18e0f3097..9427e238e 100644
--- a/winsup/cygwin/dtable.cc
+++ b/winsup/cygwin/dtable.cc
@@ -598,12 +598,7 @@ fh_alloc (path_conv& pc)
 	  fh = cnew (fhandler_mqueue);
 	  break;
 	case FH_TTY:
-	  if (!pc.isopen ())
-	    {
-	      fhraw = cnew_no_ctor (fhandler_console, -1);
-	      debug_printf ("not called from open for /dev/tty");
-	    }
-	  else if (!CTTY_IS_VALID (myself->ctty) && last_tty_dev
+	  if (!CTTY_IS_VALID (myself->ctty) && last_tty_dev
 		   && !myself->set_ctty (fh_last_tty_dev, 0))
 	    debug_printf ("no /dev/tty assigned");
 	  else if (CTTY_IS_VALID (myself->ctty))
-- 
2.39.0

Re: [PATCH v2] Cygwin: dtable: Delete old kludge code for /dev/tty.

[Corinna Vinschen]

On Jul  4 19:03, Takashi Yano wrote:
> This old kludge code assigns fhandler_console for /dev/tty even
> if the CTTY is not a console when stat() has been called. Due to
> this, the problem reported in
> https://cygwin.com/pipermail/cygwin/2023-June/253888.html
> occurs after the commit 3721a756b0d8 ("Cygwin: console: Make the
> console accessible from other terminals.").
> 
> This patch fixes the issue by dropping the old kludge code.
> 
> Though the exact reason why the kludge code was necessary is not
> clear enough, this kluge code has no longer seemed to be necessary
                                ^^^^^^^^^^^^^^^^^^^^
I'm not a native speaker myself, but

				no longer seems

might be better here.

Anyway, this is GTG.


Thanks,
Corinna

Re: [PATCH v2] Cygwin: dtable: Delete old kludge code for /dev/tty.

[Takashi Yano]

Hi Corinna,

On Tue, 4 Jul 2023 16:36:26 +0200
Corinna Vinschen wrote:
> On Jul  4 19:03, Takashi Yano wrote:
> > This old kludge code assigns fhandler_console for /dev/tty even
> > if the CTTY is not a console when stat() has been called. Due to
> > this, the problem reported in
> > https://cygwin.com/pipermail/cygwin/2023-June/253888.html
> > occurs after the commit 3721a756b0d8 ("Cygwin: console: Make the
> > console accessible from other terminals.").
> > 
> > This patch fixes the issue by dropping the old kludge code.
> > 
> > Though the exact reason why the kludge code was necessary is not
> > clear enough, this kluge code has no longer seemed to be necessary
>                                 ^^^^^^^^^^^^^^^^^^^^
> I'm not a native speaker myself, but
> 
> 				no longer seems
> 
> might be better here.
> 
> Anyway, this is GTG.

I think I understand correctly the concept of cnew_no_ctor macro in
dtable.cc now. cnew_no_ctor calls fhandler_console(void *) instead of
fhandler_console(fh_devices) to omits initialization of instance for
stat() call. This might make stat() slightly faster.

Based on this understanding, I would like to withdraw the previous
patch, and propose new patch series.

Could you please review the patch seriese?

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

Re: [PATCH v2] Cygwin: dtable: Delete old kludge code for /dev/tty.

[Corinna Vinschen]

On Jul  7 12:30, Takashi Yano wrote:
> Hi Corinna,
> 
> On Tue, 4 Jul 2023 16:36:26 +0200
> Corinna Vinschen wrote:
> > On Jul  4 19:03, Takashi Yano wrote:
> > > This old kludge code assigns fhandler_console for /dev/tty even
> > > if the CTTY is not a console when stat() has been called. Due to
> > > this, the problem reported in
> > > https://cygwin.com/pipermail/cygwin/2023-June/253888.html
> > > occurs after the commit 3721a756b0d8 ("Cygwin: console: Make the
> > > console accessible from other terminals.").
> > > 
> > > This patch fixes the issue by dropping the old kludge code.
> > > 
> > > Though the exact reason why the kludge code was necessary is not
> > > clear enough, this kluge code has no longer seemed to be necessary
> >                                 ^^^^^^^^^^^^^^^^^^^^
> > I'm not a native speaker myself, but
> > 
> > 				no longer seems
> > 
> > might be better here.
> > 
> > Anyway, this is GTG.
> 
> I think I understand correctly the concept of cnew_no_ctor macro in
> dtable.cc now. cnew_no_ctor calls fhandler_console(void *) instead of
> fhandler_console(fh_devices) to omits initialization of instance for
> stat() call. This might make stat() slightly faster.
> 
> Based on this understanding, I would like to withdraw the previous
> patch, and propose new patch series.
> 
> Could you please review the patch seriese?

Great, will do!


Thanks,
Corinna