Re: libssh write problem

[Vasuki Gubbi <gkvasuki@xxxxxxxxx>]

Anreas,

Thank you for your answer. But unfortunately, this was observed on
production system for which I did not have debug information.
But my stack trace shows a poll call when I am writing on ssh channel. Why
do we need a poll on socket when writing to a channel?

Also netstat shows no ssh socket open. So at socket level, socket is
closed, but poll is still not returned. Why is call trace struck at poll? I
am assuming this poll is poll on the socket.

Thanks and Regards,
Vasuki


On Sat, Nov 3, 2012 at 4:21 AM, Andreas Schneider <asn@xxxxxxxxxxxxxx>wrote:

> On Friday 02 November 2012 17:55:26 Vasuki Gubbi wrote:
> > Hello,
> >
> > I am using libssh 0.5.2 in a multithreaded application. I establish
> session
> > and also write simultaneously to multiple different hosts simultaneously.
> >
> > I have following code to work with pthread library.
> >
> > ssh_threads_set_callbacks(ssh_threads_get_pthread());
> > ssh_init();
> >
> > I am using sockets in blocking mode. But I see once in a while method
> > struck in channel_write call. I am enclosing the 2 threads that are
> struck
> > in this position and does not seem to comeout of it.
> >
> > Does anyone know if my usage of library is wrong or it is a some kind of
> > bug in libssh?
>
> A backtrace without debug symbols doesn't really help. Did you follow:
>
>     At all times, you may use different sessions inside threads, make
> parallel
>     connections, read/write on different sessions and so on. You *cannot*
> use
>     a single session (or channels for a single session) in several threads
> at
>     the same time. This will most likely lead to internal state corruption.
>     This limitation is being worked out and will maybe disappear later.
>
> http://api.libssh.org/stable/libssh_tutor_threads.html
>
> --
> Andreas Schneider                   GPG-ID: F33E3FC6
> www.cryptomilk.org                asn@xxxxxxxxxxxxxx
>
>
>