Re: [Expectperl-discuss] Threading on top of IO::Tty seems to work

[Bryan B. <br...@bu...>]

> Hmm, could be the wait delay in soft/hard_close which is trying to
> send signals to the spawned process via "kill". Maybe that also
> doesn't work in a thread (like fork()). Could you try closing the
> Expect objects in the main thread? Maybe that gets rid of the delay...
>
> Seems a sensible rule to me: "Create and destroy Expect objects only
> in the main thread."
>

Actually its the other way around.  If i soft/hard close the object in the
thread it takes a reasonable amount of time.  If I soft/hard close it in
the main thread it takes longer.  The actual delay is in the join
function, then closing the objects works normally.  I re-wrote the last
script to output the number of seconds elapsed and here is the output:

Getting expect object for mythtv: 0 seconds
Getting expect object for valhalla: 0 seconds
Getting expect object for eldorado: 0 seconds
Spawning thread: 1 seconds
Spawning thread: 1 seconds
Spawning thread: 1 seconds
Joining thread 0 (mythtv): 1 seconds
Completed joining thread 0 (mythtv): 16 seconds
Closing expect object: 16 seconds
Joining thread 1 (eldorado): 16 seconds
Completed joining thread 1 (eldorado): 16 seconds
Closing expect object: 16 seconds
Joining thread 2 (valhalla): 16 seconds
Completed joining thread 2 (valhalla): 16 seconds
Closing expect object: 16 seconds

You can see it takes about 15 seconds to join the first thread and then
things progress normally.

>
> BTW, anybody tried to use Net::SSH2 instead of spawning ssh? Net::SSH2
> objects are tied filehandles, so they should be usable via
> exp_init()...
>
> Cheers!
> Roland
>

I persued Net::SSH2 over a year ago for just this purpose.  You can read
the thread I had with the author here:

http://sourceforge.net/mailarchive/message.php?msg_id=200601192208.43932.dbrobins%40cpan.org

Basically David Robins stated this:

Ah, then there's the problem. Fileno tries to get a real Unix filehandle out
of the object; since it isn't a real Unix file, you won't get one.

I could not get it to work, and David seemed to think that it should not
work.  In that thread there is very simple code that I wrote and even that
doesnt work.

However, all that aside, even without using Expect, Net::SSH2 was not
thread safe.  I sent emails regarding that as well, to no avail.  At this
point in time, I really think Expect on top of a spawned ssh command is
the best way to do things (from a perl perspective).

Thanks


Bryan Bueter
http://sourceforge.net/projects/rover