winsock client closure

Hey all you winsock fans! (my cherry post!)

Ive been working on a chat server/client and am having
a problem with remote termination of a client crashing the server
Everything works fine if the remote user uses the designed
means by which to exit the prog. but if their ISP kicks it then
it crashes my server. As the winsock control for the the terminated
client is still active on the server,the server will
still try to echo back to the disconnected client. I would like to
know the most efficient way to verify connectivity and/or take
the appropriate action when it ceases.

ie. Will the 'if winsock=sckclosed' actually determine if a sudden
remote termination has taken place, like an remote system crash?

or should i 'ping' the client with a packet of data bound to a timer,
wait for a nonresponse and take the appropriate client closure
action during the error event?

im looking for the most comprehensive and most efficient answer
involving the least amount network congestion that will
allow for the continuous, fluid function of the server/host.


:)

You recieve a "Close" event when a remote system disconnects from your system.

I usually have a refresh loop that I do now and then (actually whenever there is a change in the userlist).

Which basically checks the sock and if its not connected it closes it.

VB Code:

If wsServer(x).state<>sckConnected then
    wsServer(x).close
end if

Thats not the exact code I use, because I don't have it with me right now, but you get the picture.

Make use of the Winsock Error event. i.e.

VB Code:

Private Sub Winsock1_Error(ByVal Number As Integer, Description As String, ByVal Scode As Long, ByVal Source As String, ByVal HelpFile As String, ByVal HelpContext As Long, CancelDisplay As Boolean)
    
    Select Case Number
        
        Case sckConnectionReset
        
            Debug.Print "Error: Connection reset by remote client."
        
        'Case ...
        
    End Select
    
End Sub

This will inform you of any significant event such as a disconnection etc. The constants are listed in the VB Object browser, and in MSDN.

Hope this helps.
Laterz

I'm working on a chat prog too.
Can some1 plz tell me how can i use the winsock with multi users?

http://www.vbforums.com/showthread.p...148#post649148

WOW! thanks guys!
I just got in from class and it might take me a little bit to implement
some fo the suggestions...ill let you know!
-THX!:) :) :)

HEY ...im back!

*ABDUL... yes i recieve a close event if the client closes NORMALLY
but if they're terminated buy their network connection (ie crummy ISP)
then winsock dosent evoke the close event..the only way to know
is when you try to send something else to that client and get the
error.....so far!

*Edneeis, im working on a solution in line with what you have
suggested. but im going to have to clean up my code abit to
make it work in its own seperate event ( because i have unload the wsServer()
control in another err. event ;)

*digital, I think your way is the proper way to go but i tried to evoke a
failure on my subnet and failed (ie It worked fine) so im holding out
for my friend with the crummy ISP to trip it and see whats up.
but such a remedy is obviously best left to an errorhandler ;)

SYNOPSIS
I am coding in both into the prog. and will await subsequent crashes.
Theyre not frequent but they do happen and it annoys me to see my
server crashed when i come home!) :(

Quote:

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I'm working on a chat prog too.

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Stiletto.
Each client has its own winsock control
the server loads a SEPERATE control as an array at runtime upon a connection request
ie. wsServer(x) to make the control an array, when you load the control on the server form put a 'zero' in the index box!

if you need more help there are many posts here or
i can send you a cool .zip example i dnloaded from www.vbcode.com with FULL notation included!
(i dont have the link but i have the .zip vb prog)
email me...... [email protected]

thx digital! worked great!

I unload the client when the error event occurs and Voila!
and I write the err. description ot a .log file for future reference!:D

Quote:

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Originally posted by jhov
thx digital! worked great!

I unload the client when the error event occurs and Voila!
and I write the err. description ot a .log file for future reference!:D

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:cool:;)