This is the mail archive of the
mailing list for the Cygwin project.
Re: 1.7.9 Missing SIGPIPE?
On Thu, Oct 06, 2011 at 08:29:19PM +0200, Marco Atzeri wrote:
>On 10/4/2011 6:39 PM, Christopher Faylor wrote:
>> As I mentioned in the thread, that is supposed to be implemented in
>> Cygwin. I could never see a case where it wasn't sent.
>my understanding of your explanation:
>"Sort of. If the process is doing a read, it is supposed to detect that
>the tty has been closed and a SIGHUP is supposed to be sent. It is not
>precisely the same thing as sending a SIGHUP when the master closes but
>I'm surprised that, in principle, it doesn't amount to the same thing.
>Just see any of the SIGHUPs in fhandler_tty.cc. They are all supposed
>to be dealing with this scenario.
>So, unless bash is not waiting for input (which is unlikely) this should
>- it is not implemented
>- you see no pratical case were this could be a problem as
> the program waiting for data should recognize the closure
> and correctly handling it
>Checking fhandler_tty.cc , I see no implementation, but I can be wrong
>as my understanding of cygwin internals is limited.
>I admit that mc expectation is a corner case, but the subshell closure
>was based on such assumption (src/subshell.c)
>/* Close master side of pty. This is important; apart from */
>/* freeing up the descriptor for use in the subshell, it also */
>/* means that when MC exits, the subshell will get a SIGHUP and */
>/* exit too, because there will be no more descriptors pointing */
>/* at the master side of the pty and so it will disappear. */
>so as workaround I added a SIGHUP
> kill (subshell_pid, SIGHUP);
>just before mc exit on the main, to simulate the behaviour
>and the subshell closes as needed.
>Linux and BSD correctly handle the situation while only cygwin
>was reported missing this behaviour.
I was being imprecise in my response.
I understand what you say you did. There was no reason to reexplain.
Once again, I don't understand why Cygwin's current implementation is
inadequate to handle the problem that you are seeing. You can assert
that it must be because Cygwin does not explicitly send a SIGHUP on
close and you may be right but, again, I don't see why the current
implementation, which should amount to the same thing, does not work.
Yes. It isn't explicitly implemented but it shouldn't matter.
Problem reports: http://cygwin.com/problems.html
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple