Re: console popping up unnecessarily in xterm (cygwin 1.3.3)

[Christopher Faylor <cgf at redhat dot com>]

On Sat, Oct 06, 2001 at 03:56:06AM +0900, Kazuhiro Fujieda wrote:
>>>> On 05 Oct 2001 23:21:20 +0900
>>>> Kazuhiro Fujieda <fujieda@jaist.ac.jp> said:
>
>> The same logic should also solve it on xterm. I guess another
>> bug disturbs it. As you may know, Cygwin DLL 1.3.3 has a bug
>> related to the inheritance of file descriptors in fork. It is
>> fixed in the recent development snapshots.
>
>I'm sorry. I found the logic was insufficient to solve the
>problem on xterm. The following patch should solve it.
>I feel these changes are cheap tricks. I'll make a radical
>cure in the near future.

Hmm.  I'm not sure that I understand the logic here.  I understand why
this would cure the problem with xterm since it uses a pty, but you're
now saying that if a process is using ptys it should not free its
console.  That seems sort of arbitrary.

I know that you know this.  I'm just stating it "out loud".

Of course, having said it out loud, I have no idea how to fix this any
other way, either.

I'll probably end up checking this in but I'd like to think about it a
little first.  Please bug me in a couple of days if it seems like I've
forgotten about it.

cgf


>2001-10-06  Kazuhiro Fujieda  <fujieda@jaist.ac.jp>
>
>	* winsup.h: Declare check_pty_fds.
>	* syscalls.cc (check_pty_fds): Renamed from check_ttys_fds. Also
>	check pty master.
>	(setsid): Use check_pty_fds.
>	* dtable.cc (dtable::dec_console_fds): Add check on pty fds.
>
>Index: dtable.cc
>===================================================================
>RCS file: /cvs/src/src/winsup/cygwin/dtable.cc,v
>retrieving revision 1.57
>diff -u -p -r1.57 dtable.cc
>--- dtable.cc	2001/10/03 03:49:26	1.57
>+++ dtable.cc	2001/10/05 18:38:36
>@@ -55,7 +55,8 @@ set_std_handle (int fd)
> void
> dtable::dec_console_fds ()
> {
>-  if (console_fds > 0 && !--console_fds && myself->ctty != TTY_CONSOLE)
>+  if (console_fds > 0 && !--console_fds &&
>+      myself->ctty != TTY_CONSOLE && !check_pty_fds())
>     FreeConsole ();
> }
> 
>Index: syscalls.cc
>===================================================================
>RCS file: /cvs/src/src/winsup/cygwin/syscalls.cc,v
>retrieving revision 1.155
>diff -u -p -r1.155 syscalls.cc
>--- syscalls.cc	2001/10/05 04:21:41	1.155
>+++ syscalls.cc	2001/10/05 18:38:36
>@@ -65,19 +65,20 @@ close_all_files (void)
>   cygwin_shared->delqueue.process_queue ();
> }
> 
>-static BOOL __stdcall
>-check_ttys_fds (void)
>+BOOL __stdcall
>+check_pty_fds (void)
> {
>   int res = FALSE;
>-  SetResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "close_all_files");
>+  SetResourceLock (LOCK_FD_LIST, WRITE_LOCK, "check_pty_fds");
>   fhandler_base *fh;
>   for (int i = 0; i < (int) cygheap->fdtab.size; i++)
>-    if ((fh = cygheap->fdtab[i]) != NULL && fh->get_device() == FH_TTYS)
>+    if ((fh = cygheap->fdtab[i]) != NULL &&
>+	(fh->get_device() == FH_TTYS || fh->get_device() == FH_PTYM))
>       {
> 	res = TRUE;
> 	break;
>       }
>-  ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "close_all_files");
>+  ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK, "check_pty_fds");
>   return res;
> }
> 
>@@ -270,7 +271,7 @@ setsid (void)
>     {
>       if (myself->ctty == TTY_CONSOLE &&
> 	  !cygheap->fdtab.has_console_fds () &&
>-	  !check_ttys_fds ())
>+	  !check_pty_fds ())
> 	FreeConsole ();
>       myself->ctty = -1;
>       myself->sid = _getpid ();
>Index: winsup.h
>===================================================================
>RCS file: /cvs/src/src/winsup/cygwin/winsup.h,v
>retrieving revision 1.70
>diff -u -p -r1.70 winsup.h
>--- winsup.h	2001/10/05 00:17:57	1.70
>+++ winsup.h	2001/10/05 18:38:36
>@@ -144,6 +144,7 @@ void events_init (void);
> void events_terminate (void);
> 
> void __stdcall close_all_files (void);
>+BOOL __stdcall check_pty_fds (void);
> 
> /* Invisible window initialization/termination. */
> HWND __stdcall gethwnd (void);
>
>____
>  | AIST      Kazuhiro Fujieda <fujieda@jaist.ac.jp>
>  | HOKURIKU  Center for Information Science
>o_/ 1990      Japan Advanced Institute of Science and Technology

-- 
cgf@cygnus.com                        Red Hat, Inc.
http://sources.redhat.com/            http://www.redhat.com/