Re: [myhdl-list] Module uses globals

[Christopher F. <chr...@gm...>]

On 4/16/15 3:11 AM, Henry Gomersall wrote:
> On 15/04/15 21:29, Christopher Felton wrote:
>> <snip>
>>>>>>>>
>>>>>>>> This totally defeats the beauty of object orientation in Python. For
>>>>>>>> example you cannot have two instances of a Simulation() at the same time.
>>>>>>
>>>>>> What is the rationale for more than one simulation
>>>>>> running at a time?  Why have two simulators running?
>>>>>>
>>>>
>>>> What is great about having a HDL simulation within a full blown language
>>>> like Python is the possibility of doing unconventional things. Some that I
>>>> can think of are, first, running a same model in delayed and asynchronous
>>>> versions, with a controlled, time varying delay and comparing states.
>> Sure, folks have experiment with aysnc simulations before
>> but did not require two simulation instances.
>>
>
> One thing that is quite hard to do is making blocking calls without
> pausing the simulator. It is always possible to run the blocking code in
> its own thread with polling on every tick, but there is plausibly a neat
> model with separate simulations representing entities that are not
> synchronous to one another.

In my opinion, you would not want to make "blocking"
calls because you are mixing the thread scheduling and
the simulator scheduling - bad idea.

Now, you might want to leverage some of the Python
communication objects like Queue but I would not use
them blocking (because of the mixed scheduling).

Taking the Queue as an example, I have wrapped it to
works with the Simulator:
https://github.com/cfelton/test_jpeg/blob/master/test/support/_SignalQueue.py

This way I can uses a Queue (non-blocking) with the
simulator scheduler.

Regards,
Chris