Re: TCP wait_for transmit question

[Richard Mortier <Richard.Mortier@xxxxxxxxxxxxxxxx>]

On 14 Jul 2012, at 17:10, Anil Madhavapeddy wrote:

> Interesting; so this check is also clamped to the TX MSS
> (Tcp.Pcb.write_available) and not to the max_size of the application
> buffer.
> 
> This is probably a good time to nail down the semantics of all these
> different modules, particularly as vchan/shmem will be coming along
> shortly.
> 
> Channel: buffered I/O, manual flush required
> Flow: unbuffered I/O, will be triggered immediately
> Tcp.Pcb: buffered if delay writes are used, unbuffered with nodelay
> 
> The TCP Nagle's buffer is necessary since only it knows if there are TX
> packets in flight, whereas the Channel module doesnt...

naive question- what's the relationship between Tcp.Pcb and Flow then?  ie., if 
i have a tcp connection underneath with nagling turned on, is my flow genuinely 
unbuffered, or just mostly so?


-- 
Cheers,

R.




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