[zeromq-dev] Non-contiguous message thoughts

[Martin Sustrik]

Hi Brian,

> I haven't been able to follow this thread very closely, but I do have
> one question:
> 
> You can already do non-copying sends of non-contiguous memory using
> 0MQ, you just have to send multiple messages.  What additional benefit
> would message groups give beyond that?

It's atomicity. Imagine load-balancing socket such as ZMQ_DOWNSTREAM. If 
there are two peers connected and you send 2 messages, one message will 
go to one peer while the second goes to the another.

Also, you don't want 0MQ to deliver 1st part of the message while 
remaining parts are not yet available. That kind of thing can possibly 
cause deadlocks.

Martin