[lkml]   [1998]   [Sep]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Linux tcp/ip code has trouble with async network I/O notification,
Wim Ten Have wrote:

> I think that there is a major ;-) problem around in the Linux TCP/IP
> code when using Async (SIGIO) controlled network code setups.


> The idea of the re pro is that a certain server process needs ASYNC
> I/O notification when recv network I/O is possible. Under Linux
> this only works "well" for local clients though clients routed via
> external physical devices have difficulties.


> Some understanding wrt this problem I currently hold is that the
> SIGIO is posted before the socket connection state is set to
> ESTABLISHED making the select(2) miss the available data. Local
> clients have the advantage that their data is already available so I
> think they are served by accident.

After all the stupid flamage (my threads are bigger than yours kind of things), I
remember having found some messages in linux-java where they basically came to the
conclusion that in Linux the SIGIO is delivered before the full TCP handshake is
I was able to reproduce the bad behavior when connecting accross a modem, but not
locally or on the same (idle) subnet.
There is a patch hanging somewhere for 2.0.3x. The problem was said to be fixed in
2.1.xx (which obviously isn't). I will look for the patch if I can still find it.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:44    [W:0.076 / U:12.764 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site