[Click] Master::run_selects with socket element bug

[Eddie Kohler]

Hi Beyers,

How exactly do you mean "hard lock"?  The kernel hangs?  Are you running 
kernel Click?

So I ran this config:

InfiniteSource -> Socket(TCP, 0.0.0.0, 9000) -> Print -> Discard; 
TimedSource(1) -> Print -> Discard

and telneted to the relevant port, then suspended the telnet.  The receive 
window dropped to 0, but the timedsource continued just fine.

Eddie


Beyers Cronje wrote:
> Hi all,
> 
> I'm picking up a bug in the following scenario. I have a socket element 
> that sends data to a remote host via a TCP stream socket. Everything 
> works perfectly until the remote host TCP Window size reaches 0, as soon 
> as this happens I get a hard lock on the click box. I suspect the 
> problem comes in somewhere in the Master::run_selects function. I have 
> confirmed the hang does not occur anywhere in the socket element itself.
> 
> Anyone has any pointers for where I should start looking? What does  
> poll() or select() return on a TCP socket when the remote host has a TCP 
> window size of 0?
> 
> Any pointers will be greatly appreciated :)
> 
> Cheers
> 
> Beyers