[zeromq-dev] P/Invoke-based CLR access to zeroMQ

Martin Sustrik sustrik at fastmq.com
Mon Feb 23 11:03:41 CET 2009


> Well, the CLR is an amazing piece of technology. Please check the
> attached dnzmq.cs, I think I made the Send function work without
> modifications to the C-API. So all that's needed now would be a receive
> with a allocator callback.

It looks pretty elegant.

> There is just one minor problem: with messages of 512 bytes size, the
> original copy-based implementation is twice as fast as the new one...


This is why I've proposed to use zero-copy only for large messages. On 
low layers (like OS kernel) the low limit for messages to be more 
effective with zero-copy is somewhere at several kilobytes of size. With 
the functionality on higher level of stack, this limit may be even higher.

Once we have a little time we'll give your implementation a try testing 
it for different message sizes. Testing it for both zero-copy and copy 
algorithms should yield 2 linear graphs. The intersection of the two 
lines should be a located at the message size where zero-copy starts to 
be more efficient than copy algorithm.

Btw, we've fixed the bugs you've reported and merged the fixes into the 
trunk. The only exception is the SCTP-related problem which will take a 
some time to fix as we are having problems with SCTP API not being fully 
standardised at the moment.


More information about the zeromq-dev mailing list