socket.rcv timeout while-loop

[Stephen Hansen]

On 2/4/11 6:55 AM, Dwayne Blind wrote:
> @ Jean-Michel Pichavant
> I am writing a small multiplayer game. Several clients are connected to
> the server. Games last, say, 20 seconds.
> You can think of the game as a small chat lasting 20 seconds. All the
> data received by the server is sent back to the clients.
>  
> @ Stephen Hansen
> Each player can send as many words as he wants. I think this is why I
> need the loop. Don't you think so ?

No. I've never seen or used network code which operated in any way like
that. Sometimes you want code which blocks, sometimes you want code that
doesn't: sometimes you want stuff that may block for a little while, but
with a timeout.

I can't even imagine why you'd want code which aggressively tries to
read for multiple seconds before moving on.

Either the read works and you have data; or it doesn't, and you move on
to do something else and try again later. Perhaps after trying to read
from another socket-- or, perhaps after a select.select() call tells you
there's something more to read. T

But you need to separate the logic of your game from this network
infrastructure.

From your game logic perspective, perhaps you process the responses line
by line. From your network logic perspective, you may happen to get one
character at a time-- or it may burst to you all at once. The socket
interfaces will try to give you up to the requested number of bytes but
the network layer has every possibility of just giving you partial
responses.

So the network layer should just gather up the data as it arrives,
buffer it -- and pass it off to the game logic layer as each line is
complete (i.e., as \r\n or \n's are received). But there's no reason at
all to do a while loop to aggressively try to read from one particular
socket repeatedly for multiple seconds. At least, none that I've ever
run into.

Granted, I'm not at all a master of socket-fu.
-- 

   Stephen Hansen
   ... Also: Ixokai
   ... Mail: me+list/python (AT) ixokai (DOT) io
   ... Blog: http://meh.ixokai.io/

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