[Haskell] A simple server (or how to do io).
ekarttun at cs.helsinki.fi
Tue Dec 20 21:43:34 EST 2005
On 20.12 21:52, Pupeno wrote:
> It works, but I have the following problems:
> When I run server "10013" from ghci, the prompt returns immediately and if I
> do a query to that port I don't get anything, until I go and press enter on
> ghci and the daytime is sent to the client. Like if the prompt was blocking
> all IO or something like that.
> The other problem is that I tried to make a program, so I made
Your problem is that the ghci prompt *is* blocking everything. ghci is
builded non-threaded. Ghci uses a blocking call to read the lines
which means that all other computations are stopped.
> I compile it and run it. It returns immediately and the server of course, is
> not running.
It spawns the server threads and returns immediately.
> I think what I am missing is that server, after running runStreamServer should
> block and be able to reply to all the queries (in the final version I'll also
> have runDgramServer as well) and be able to receive a signal, upon which it
> should close the socket and finish. How can do that ? Any help will be
Catch the signal and kill the listening threads. If you
are using the new 0.3.1 release then you can use the
ps. I think it may be best to continue on haskell-cafe@ rather
than the main list.
- Einar Karttunen
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