Boston Linux & Unix (BLU) Home | Calendar | Mail Lists | List Archives | Desktop SIG | Hardware Hacking SIG
Wiki | Flickr | PicasaWeb | Video | Maps & Directions | Installfests | Keysignings
Linux Cafe | Meeting Notes | Blog | Linux Links | Bling | About BLU

BLU Discuss list archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

send problem

I'm having a really wierd problem with a bit of C code

I have an array of socket file descriptors that is looped though and
messages sent to.  If one of the remote applications dies it causes a
broken pipe in the application...

I'll try and illistrate the problem.

step 1)
when the client is working the network connections look like this:
Everything works perfectly and send returns the number of bytes written as

step 2)
But when the client dies the network switches to this:
server<=FIN_WAIT2 = client
server =CLOSE_WAIT=>client
But when you send data from the server it _still_ return the number of
bytes in the message as if it was a good connection.  ie if I sent
"Linux\0" it would return 6.  I was assuming that because the client is
dead that send would fail and return send's error code (-1) but it doesn't.
And errno doesn't seem to have anything usefull in it either :(

When the send has happened however the connection finally goes away.

step 3)
If it tries another send the program just gets a "Broken pipe" error
(inside send) and dies (with no core thank you very much)  Now I know why
the broken pipe is occuring... there is no connection to send across. but I
would think I should also get an error code returned here... but no.

So does anyone have any idea why am I not getting an error code at either
step 2 or 3?


BLU is a member of BostonUserGroups
BLU is a member of BostonUserGroups
We also thank MIT for the use of their facilities.

Valid HTML 4.01! Valid CSS!

Boston Linux & Unix /