[zeromq-dev] patch: non-blocking tcp accept

[Martin Sustrik]

Hi Dhammika,

> Patch to add non-blocking tcp accept.
> 
> 1. sets non-blocking flag in tcp listener socket
> 2. moves accept to tcp_listener.in_event()
> 3. passes native socket descriptor to tcp_socket constructor
> 
> Builds and tested on linux.
> Would appreciate if someone can run a quick build on a win32 box.
> Hopefully it'll build without any drama.
> 
> Requires few changes in zmq_server, perf and examples (mainly in
> tcp_socket constructor).
> If we're happy with this, I'll send a full patch.

The patch looks OK. Please, do send the full patch (and state it's 
licensed under MIT license).

The one thing I'm unsure of is EAGAIN/EWOULDBLOCK distinction. It seems 
that both Linux and Win32 assign the same numeric value to both errors. 
I am not sure of other platforms.

POSIX says:

[EAGAIN]
     Resource unavailable, try again (may be the same value as 
[EWOULDBLOCK]).

[EWOULDBLOCK]
     Operation would block (may be the same value as [EAGAIN]).

Pretty confusing...

Martin