Re: [pysnmp-users] CLI interaction?

[Ilya E. <il...@gl...>]

The first thing I do not quite understand is why your SNMP call blocks
(?) your cly app if your (blocking) pysnmp code runs in a dedicated
thread. Can you please elaborate on that point?

Alternatively, as Craig says, you may try to switch your stdin file
descriptor into non-blocking mode and serve both FD's (SNMP and stdin)
by a single select() within a main loop.

To start with the second approach, I'd investigate the way how to extent
ply input driver to run non-blocking and being managed by a select().
I've looked at the ply code:

https://github.com/alecthomas/cly/blob/master/cly/interactive.py

so ReadlineDriver class is the place that should probably be
hacked/extended to replace blocking raw_inpit() with a non-blocking and
select()-managed version like discussed here:

http://stackoverflow.com/questions/9027311/how-to-make-non-blocking-raw-input-when-using-eventlet-monkey-patch-and-why-it

Once this is working, I could elaborate on
two-FDs-been-managed-by-single-select thing. I will probably try to come
up with an example script to make it generally useful.

-ilya

On 11/12/2015 11:15 AM, Craig Small wrote:
> Avtually re-reading your email, its not two sockets its an interactive
> terminal and a socket. What you can do is put your stdin socket (well
> FD) into the socket map. That way the select() is looking at both your
> network SNMP socket/fd and your keyboard stdin
> 
>  - Craig
> 
> 
> On Thu, Nov 12, 2015 at 9:09 PM Craig Small <cs...@en...
> <mailto:cs...@en...>> wrote:
> 
> 
>     Get's a bit tricky with sockets floating around. What I had to do
>     was create a new SNMP engine and dispatcher that used my own
>     socket_map. The socket_map is important because this is what the
>     select() system calls to listen for the sockets. You can have only
>     one select()
> 
>     You then need to run the dispatcher's jobsArePending and
>     handleTimerTick to keep the the snmp dispatcher happy.
> 
>     I then have the the socket running select(), because you have used
>     YOUR socket_map then pysnmp has added its socket to the map.
>     I asked almost the very same thing and Ilya responded here:
> 
>     http://sourceforge.net/p/pysnmp/mailman/message/31494830/
> 
> 
> 
>     On Thu, Nov 12, 2015 at 11:57 AM Michael R Anderson
>     <mic...@gm... <mailto:mic...@gm...>>
>     wrote:
> 
>         I am using cly to drive my CLI.  It works great.  I recently added
>         pysmp.  Now when it gets to runDispatcher() (in it's own thread), it
>         looks like my CLI input line gets hijacked so that no more command
>         line input can be done.
> 
>         I read runDispacther uses an I/O mainloop somehow.  Can this be
>         causing my CLI is no responsive problem?
> 
>         Any suggestions?
> 
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