.net socket question

[Silby]

I've been messing around with sockets for a bit and i got most of it down (i
think).
The server side is an asynchronous tcp socket listener with sits and waits
for data.
The client side uses TcpClient to connect.
Connecting, sending and receiving data, error handling, ... all works fine.
The problem is when closing the connection.

Now as i understand it, closing the socket works as follows:
client -> tcp finish command
server -> acknowledges and sets its own finish command
client -> acknowledges again

What i do in code is just this
myTCPClient.close()
Which i think should handle all the internal commands to wrap up (right ?,
they are tpc sockets afterall). This results in the server socket going
into CLOSE_WAIT state, and the client socket going into FIN_WAIT_2 state.
They stay in that state until i close either the server or the client.
I tried making the async socket do a close command too, but that didnt
change anything at all.
I've searched through almost all the documentation i could find, but i must
still be missing something.

Could someone tell me what it is i still need to do to wrap up closing the
sockets ...

[Jeremy Cowles]

> Could someone tell me what it is i still need to do to wrap up closing the

sockets ...
This is an issue with the TcpClient, not with windows sockets. What I did to
fix the problem, and still keep the functionality of the TcpClient, is I
inherited the TcpClient, and then exposed the underlying socket. The Close
method on the socket actually works, and it also allows you to check to see
if the socket is still connected. To disconnect, something like this should
close the connection 100%:

If TcpClientEx.IsConnected Then
TcpClientEx.Client.Shutdown(SocketShutdown.Both)
TcpClientEx.Client.Close()
TcpClientEx.Close()
End If
Here is the TcpClientEx Class:

Public Class TcpClientEx
Inherits Net.Sockets.TcpClient

Sub New()
Call MyBase.New()
End Sub

Sub New(ByVal LocalEP As Net.IPEndPoint)
Call MyBase.New(LocalEP)
End Sub

Sub New(ByVal HostName As String, ByVal Port As Integer)
Call MyBase.New(HostName, Port)
End Sub

Public Shadows Property Client() As Net.Sockets.Socket
Get
Return MyBase.Client
End Get
Set(ByVal Value As Net.Sockets.Socket)
MyBase.Client = Value
End Set
End Property

Public ReadOnly Property IsActive() As Boolean
Get
Return Me.Active
End Get
End Property

Private Function IsConnected() As Boolean
If Me.Client.Connected = False Then
Return False
Else
Dim bState As Boolean = Me.Client.Poll(1,
System.Net.Sockets.SelectMode.SelectRead)

If bState And (Me.Client.Available = 0) Then
Return False
Else
Return True
End If
End If
End Function
End Class
HTH,
Jeremy

"Silby" <Si***@nothanks.com> wrote in message
news:xf********************@phobos.telenet-ops.be... I've been messing around with sockets for a bit and i got most of it down (i think).
The server side is an asynchronous tcp socket listener with sits and waits
for data.
The client side uses TcpClient to connect.
Connecting, sending and receiving data, error handling, ... all works fine. The problem is when closing the connection.

Now as i understand it, closing the socket works as follows:
client -> tcp finish command
server -> acknowledges and sets its own finish command
client -> acknowledges again

What i do in code is just this
myTCPClient.close()
Which i think should handle all the internal commands to wrap up (right ?,
they are tpc sockets afterall). This results in the server socket going
into CLOSE_WAIT state, and the client socket going into FIN_WAIT_2 state.
They stay in that state until i close either the server or the client.
I tried making the async socket do a close command too, but that didnt
change anything at all.
I've searched through almost all the documentation i could find, but i must still be missing something.

Could someone tell me what it is i still need to do to wrap up closing the
sockets ...

[Silby]

This seems to do it, thanks .. I'd been struggling for days (and days to
come) !

"Jeremy Cowles" <jeremy.cowles[nosp@m]asifl.com> wrote in message
news:AD*********************@twister.tampabay.rr.c om...

Could someone tell me what it is i still need to do to wrap up closing the sockets ...
This is an issue with the TcpClient, not with windows sockets. What I did

to fix the problem, and still keep the functionality of the TcpClient, is I
inherited the TcpClient, and then exposed the underlying socket. The Close method on the socket actually works, and it also allows you to check to see if the socket is still connected. To disconnect, something like this should close the connection 100%:

If TcpClientEx.IsConnected Then
TcpClientEx.Client.Shutdown(SocketShutdown.Both)
TcpClientEx.Client.Close()
TcpClientEx.Close()
End If
Here is the TcpClientEx Class:

Public Class TcpClientEx
Inherits Net.Sockets.TcpClient

Sub New()
Call MyBase.New()
End Sub

Sub New(ByVal LocalEP As Net.IPEndPoint)
Call MyBase.New(LocalEP)
End Sub

Sub New(ByVal HostName As String, ByVal Port As Integer)
Call MyBase.New(HostName, Port)
End Sub

Public Shadows Property Client() As Net.Sockets.Socket
Get
Return MyBase.Client
End Get
Set(ByVal Value As Net.Sockets.Socket)
MyBase.Client = Value
End Set
End Property

Public ReadOnly Property IsActive() As Boolean
Get
Return Me.Active
End Get
End Property

Private Function IsConnected() As Boolean
If Me.Client.Connected = False Then
Return False
Else
Dim bState As Boolean = Me.Client.Poll(1,
System.Net.Sockets.SelectMode.SelectRead)

If bState And (Me.Client.Available = 0) Then
Return False
Else
Return True
End If
End If
End Function
End Class
HTH,
Jeremy