How to use two threads (GUI and backend)

[jmp]

On 10/26/2016 02:45 PM, pozz wrote:
> Il 26/10/2016 13:16, jmp ha scritto:
>> [...]
>> I suggest you write a GUI that make synchronous    calls to a remote
>> application, if possible. If the remote app is in python, you have
>> access to remote protocols already written for you, Pyro is one of them,
>> you can skip the low level communication part.
>
> I'm not sure Pyro (or similar alternatives) helps in my case.
>
> The real problem is that retrieving status from remote device is a slow
> operation.  If the GUI thread blocks waiting for the answer, the GUI
> blocks and the user complains.
>
>  From Pyro documentation:
> ---
> Normal method calls always block until the response is returned. This
> can be any normal return value, None, or an error in the form of a
> raised exception. The client code execution is suspended until the
> method call has finished and produced its result.
> ---
>
> So, even with Pyro, I need to have another thread that manages Pyro
> communication (instead of serial communication)... additional problems.
>

Also from the Pyro doc:

You can execute a remote method call and tell Pyro: “hey, I don’t need 
the results right now. Go ahead and compute them, I’ll come back later 
once I need them”. The call will be processed in the background and you 
can collect the results at a later time.

[...]

It is possible to define one or more callables (the “call chain”) that 
should be invoked automatically by Pyro as soon as the result value 
becomes available.

jm