tty-slave read() patch

[Christopher Faylor]

On Wed, Feb 28, 2001 at 11:53:10PM +0300, Egor Duda wrote:
>CF>    Won't  this  cause  problems when communicating with non-cygwin
>CF> applications?
>
>as far as i can understand from source, if slave have pipe's handle to
>get  input  from  master, it can assume that master is cygwin process.
>that  means  that  opening input_mutex from slave's side is safe, this
>mutex  (end  event) should already exist. if cygwin master opens  pipe
>and  communicate   though  it  with  non-cygwin  child, it will freely
>acquire and release input mutex, since noone else hold it.
>
>the  only  possible  problem is that master can have two children, one
>cygwin  and  one non-cygwin, and they both are trying to read. in this
>case  it's  possible that cygwin child will see input_available_event,
>but  won't  see  any  data in pipe, since non-cygwin child had already
>eaten it. but i think it was the same in old code, too.
>
>i've  tested  it  in  either  tty  or  notty  mode and with non-cygwin
>programs in local console and via ssh.

So, a non-cygwin program running under ssh, via a pty, will work correctly?
In that case, check her in, with much thanks.

One minor nit, however.  Please adhere to the coding standards of the
code your changing.  You seem to have added at least one or two
cases of:

	foo ( bar );

rather than

	foo (bar);

It's also:

	if (!foo)

not
	if (! foo)

(I don't know if you've done this, but I do find it, from time to time,
in cygwin code.)

Thanks again.  It sounds like this could speed up pty/tty handling in
cygwin.

Will this even get rid of the cvs/ssh hang problem on Windows 95?

cgf