[Twisted-Python] verilog simulation calling out to twisted

[Bryan Murdock]

Hi,

I've been writing Verilog simulations for years, and tinkering with
Python for years.  In the last couple years I have been calling out to
Python from Verilog simulations, which has been awesome.  Just this
week I tried twisted out for the first time to write a simple custom
TCP server.  It was a great experience and even though I still know
next to nothing about twisted, I think I'm in love :-)

Now I have a crazy idea.  I'd like that Python code that my Verilog
calls out to to use twisted.  OK, actually I've already done that, my
Verilog calls out to my that TCP server that I wrote.  I had to spawn
a thread and run the server in that thread so that the Verilog could
continue to do stuff in parallel with the server.  It's working great.

The real crazy thing I want is for the Verilog to call out to a
twisted TCP client as well.  Again, I need the client and server to
not block the Verilog.  My first attempt was to run client and server
in two separate threads.  I start the server thread, then I start the
client thread and only in the client thread do I call reactor.run().
It seems to not be working.  Before I try to figure out why, I thought
I might ask here if it even should work.

Here's a different way to explain it, in case that helps:

main thread is verilog which spawns server_thread

def server_thread():
    reactor.listenTCP(ServerFactory())

main thread spawns client_thread

def client_thread()
    reactor.connectTCP(ClientFactory())
    reactor.run()

I read the page on threads in twisted and I'm guessing  Would it be
better to have the main thread just spawn one thread that does this?

def client_server_thread():
    reactor.listenTCP(...)
    reactor.connectTCP(...)
    reactor.run()

Hmm, as I finish typing this all out, I'm realizing that surely
someone has written at TCP proxy (essentially what this verilog
simulation is doing) in twisted before.  A quick internet search tells
me yes...and of course they are not using threads.

The way the whole verilog mess is written right now it would be much
easier to use separate threads for client and server.  Is that
possible?  If not I'll have to find a way to justify re-architecting
the verilog mess.

Thanks,

Bryan