OT - advice on async I/O pls

[Terry Horsnell]

Apologies for this off-topic post. Pls point me elsewhere if
there's a more suitable list.

I'm using sendto and rcvfrom to handle a UDP connection to a
remote host. I send a msg using sendto, and then wait for
a reply using recvfrom, but I would like to be able to rapidly
timeout the rcvfrom if the remote host is down.

The async I/O set of commands aio_* offer what looks like
the perfect solution, but they require that I use aio_read
and aio_write (equivalent to read(2) and write(2) ) rather
than sendto/recvfrom.

I'd rather not sit in a loop waiting for a reply with
non-blocking I/O enabled. I'd much prefer to use blocking
I/O and have the recvfom come back to me either when the
input has completed, or it has timed out.

Any suggestions how I might achieve this?

Cheers,
Terry

[Siddhesh Poyarekar]

On Mon, 2009-04-06 at 11:29 +0100, T. Horsnell wrote:
>  I'm using sendto and rcvfrom to handle a UDP connection to a
>  remote host. I send a msg using sendto, and then wait for
>  a reply using recvfrom, but I would like to be able to rapidly
>  timeout the rcvfrom if the remote host is down.
>  
>  The async I/O set of commands aio_* offer what looks like
>  the perfect solution, but they require that I use aio_read
>  and aio_write (equivalent to read(2) and write(2) ) rather
>  than sendto/recvfrom.
>  
>  I'd rather not sit in a loop waiting for a reply with
>  non-blocking I/O enabled. I'd much prefer to use blocking
>  I/O and have the recvfom come back to me either when the
>  input has completed, or it has timed out.
>   
Check out GIOChannels in glib2:

http://library.gnome.org/devel/glib/stable/glib-IO-Channels.html

Siddhesh

--
http://siddhesh.in

[Gilboa Davara]

On Mon, 2009-04-06 at 11:29 +0100, T. Horsnell wrote:
>  Apologies for this off-topic post. Pls point me elsewhere if
>  there's a more suitable list.
>  
>  I'm using sendto and rcvfrom to handle a UDP connection to a
>  remote host. I send a msg using sendto, and then wait for
>  a reply using recvfrom, but I would like to be able to rapidly
>  timeout the rcvfrom if the remote host is down.
>  
>  The async I/O set of commands aio_* offer what looks like
>  the perfect solution, but they require that I use aio_read
>  and aio_write (equivalent to read(2) and write(2) ) rather
>  than sendto/recvfrom.
>  
>  I'd rather not sit in a loop waiting for a reply with
>  non-blocking I/O enabled. I'd much prefer to use blocking
>  I/O and have the recvfom come back to me either when the
>  input has completed, or it has timed out.
>  
>  Any suggestions how I might achieve this?
>  
>  Cheers,
>  Terry
>   
Have you considered using non-blocking send/recv and then use select to
"wait" on the socket(s)?
It's a far cheaper (performance wise) solution.

- Gilboa