Cancel read on socket

[Leon Pollak]

On Tuesday, 27 בMay 2008, Torsten Landschoff wrote:
> Leon Pollak wrote:
> > Is there any way to cancel currently waiting read operation on UDP
> > socket? I do not want to close it (need to use it immediately) or use
> > select() (consumes a lot of CPU time).
>
> Why does select() consume a lot of CPU time!? 
Just look into the code...
Well, everything in this world is relative...:-)
The code has a lot of operations, even rtems calls...


> Wouldn't it be obvious to 
> fix select() then? Or poll for that matter...
I do not think the select needs fixing - it does fine what it should do...


> AFAIK, the standard approach is to use a non-blocking socket, try a read
> and only use select() if no data was available.
My case is simple: other side sends A LOT of data all the time. Then, once 
upon a time from another task I send it "stop". The receiving task hangs 
on 'read', while I need it to exit from read, do something and return back.

I do not want to waste the CPU for 99% unnecessary work doing select() or 
checking asynchronous ready.

The Joel's suggestion will allow to solve the issue with just one 'if' 
operator.


> Sorry for not knowing a better/tested solution...
>   Torsten

Thanks for your willing to help.

-- 
Leon