hacking - aio_sendfile()

[Adrian Chadd]

Hiya,

I'm more interested in the API than the implementation at the moment.

Yes, you're right - it should eventually be driven using disk io
completion upcalls which triggers the push of data into the socket
buffer. I totally agree.

I'm hacking up some libevent-ish looking thing that uses kqueue and
wraps aio, read, write, and other event types into something I can
easily shoehorn this stuff into. I'll then throughly test it (and
other options) out. You're right, it's likely going to end up with a
whole lot of aio threads sitting there waiting for disk IO to complete
- and at that point, I'll start hacking at sendfile() to split it into
two halves and have it driven by a completion call from g_up or
wherever, triggering the socket write side of things.

There are some other questions too - like whether the IO completion
should just queue socket IO (and have it potentially block in the TCP
code) or whether it should funnel completions into a per-CPU aio
completion thread which does the socket write bit. That way disk IO
completion isn't going to be blocked by longer-held locks in the
networking stack.

Thanks,


-adrian