Tcp Server for several clients data conflict ?

[Sharon]

I'm writing a TCP server that receive data from several clients.

The code:

Socket clientSocket = server.AcceptSocket(); // server is a TcpListener
object.

And now I start a thread that handle the clientSocket received data from the
client, and I going back to wait on the server.AcceptSocket() above for the
new client, and so on.

The trouble is that thread that handle one client receive data sent from
another client. And this is bad for me !
For each accepted socket the RemoteEndPoint is different but the
LocalEndPoint is the same, I think this is the trouble, but I do not know I
how to fix it. Here is the server must listen on a single port but should
handle several sockets connections at the same time. I guess every new socket
should be moved to a different port, but I found no way to do this.
Can anyone help we with that?

---------
Thanks
Sharon

[Claire]

Nope, that's right. You must be doing something wrong in your code, servers
are meant to be able to accept multiple connections on a single socket
I haven't done any dotnet socket stuff yet so can't help.
Can you post some of your code.

[Sharon]

Ok, here is the summarized code I'm using:

///////////////////////////////////////////////////////////////////////////////
IPAddress DEFAULT_SERVER = IPAddress.Parse("127.0.0.1");
IPEndPoint ipNport = new IPEndPoint(DEFAULT_SERVER, 31001);
TcpListener m_server = new TcpListener(ipNport);

while( true )// For ever for this example
{
Socket clientSocket = m_server.AcceptSocket();
Thread m_clientListenerThread = new Thread(new
ThreadStart(SocketListenerThreadStart));
m_clientListenerThread.Start();
}

private void SocketListenerThreadStart()
{
int size = 0;
byte [] byteBuffer = new byte[131072];// 128 Kilobyte.

while( true )// For ever for this example
{
size = m_clientSocket.Receive(byteBuffer);
// ERROR: In here I get mixed data, I mean that I get data received
from more then one client !!!
}
}
///////////////////////////////////////////////////////////////////////////////

Any idea???

------------
Thanks
Sharon

[Claire]

Where is "m_clientSocket" set? I can see "clientSocket" in the first bit but
I can't see where the m_clientSocket comes from in the thread method.
If there are several, check you're selecting the correct one.

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

What is happening is that m_clientSocket variable is defined as an instance
member, hence it's available to all the thread, when a new socket is
received you assign to m_clientSocket the new one, losing the old one and
hence the mix

do this, use a Sync queue
Queue q = Queue.Syncronized( new Queue );

while(true)
{
Socket clientSocket = m_server.AcceptSocket();
q.Push( clientSocket )
.....
}

in the listening method:
private void SocketListenerThreadStart()
{
Socket clientSocket = (Socket) Queue.Pop();
..
Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation


"Sharon" <Sh****@discussions.microsoft.com> wrote in message
news:8A**********************************@microsof t.com...

Ok, here is the summarized code I'm using:

///////////////////////////////////////////////////////////////////////////////
IPAddress DEFAULT_SERVER = IPAddress.Parse("127.0.0.1");
IPEndPoint ipNport = new IPEndPoint(DEFAULT_SERVER, 31001);
TcpListener m_server = new TcpListener(ipNport);

while( true )// For ever for this example
{
Socket clientSocket = m_server.AcceptSocket();
Thread m_clientListenerThread = new Thread(new
ThreadStart(SocketListenerThreadStart));
m_clientListenerThread.Start();
}

private void SocketListenerThreadStart()
{
int size = 0;
byte [] byteBuffer = new byte[131072];// 128 Kilobyte.

while( true )// For ever for this example
{
size = m_clientSocket.Receive(byteBuffer);
// ERROR: In here I get mixed data, I mean that I get data received
from more then one client !!!
}
}
///////////////////////////////////////////////////////////////////////////////

Any idea???

------------
Thanks
Sharon

[Sharon]

Sorry, I posted typing error, here is the fix one,
The clientSocket and the m_clientSocket are the same socket which is data
member of the class:

///////////////////////////////////////////////////////////////////////////////
IPAddress DEFAULT_SERVER = IPAddress.Parse("127.0.0.1");
IPEndPoint ipNport = new IPEndPoint(DEFAULT_SERVER, 31001);
TcpListener m_server = new TcpListener(ipNport);

while( true )// For ever for this example
{
Socket m_clientSocket = m_server.AcceptSocket();
Thread m_clientListenerThread = new Thread(new
ThreadStart(SocketListenerThreadStart));
m_clientListenerThread.Start();
}

private void SocketListenerThreadStart()
{
int size = 0;
byte [] byteBuffer = new byte[131072];// 128 Kilobyte.

while( true )// For ever for this example
{
size = m_clientSocket.Receive(byteBuffer);
// ERROR: In here I get mixed data, I mean that I get data received
from more then one client !!!
}

///////////////////////////////////////////////////////////////////////////////

Hope it's clear now.

-----------
Thanks
Sharon

[Claire]

So every time a new client attaches, the value of m_ClientSocket changes, as
Ignacio and I suspected.
You need to store an array of client sockets, check which one you need to
use in the thread method before storing data from it.

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

He may use a Sync queue as I shown in my previous post, it does work fine
that way

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Claire" <as*******@ntlworld.com> wrote in message
news:%2******************@TK2MSFTNGP14.phx.gbl...

So every time a new client attaches, the value of m_ClientSocket changes,
as Ignacio and I suspected.
You need to store an array of client sockets, check which one you need to
use in the thread method before storing data from it.

[Sharon]

Thanks

[Sharon]

Thanks