Re: [RTnet-developers] Maintaining UDP sockets in a hash instead of a list.

[Gilles C. <gil...@xe...>]

Wolfgang Grandegger wrote:
> Hi Gilles,
> 
> Gilles Chanteperdrix wrote:
>> Hi,
>>
>> here is another patch to RTnet, which replaces the list of UDP sockets
>> with a hash, so makes the searching for an RTnet registered socket a bit
>> faster.
> 
> What does a "bit faster" mean. I'm curious, do you have some benchmark 
> figures at hand?

No, but the current scheme is to test every packet against every socket 
(until one is found). This is O(N).
With a hash, and a well dimensioned/behaved system, you get O(1).
So, no doubt there is a gain, at least on systems with many sockets 
opened, and especially when you receive many non real-time UDP packets 
which you must send to the proxy: non real-time packets are tested 
against all opened sockets, to finally find that they are matching none 
of them.

-- 
                                                  Gilles.