Thanks for your answers... let me get a bit deeper into
the issue then. I'm doing some custom socket-
communications. I basically used the on-line help
examples to build this app. It all works fine and dandy..
UNTIL I set up a test program and simulated mulitiple
requests coming in at the same time.
My understanding is, this: BeginAccept just gets the ball
rolling and passes off a new socket which I use from there
on out. BeginReceive says, ok, let's get the conversation
going. Then you loop through BeginReceive building your
message if it is over your buffer size. At this point,
you process the message and send a response using
BeginSend. (My code is listed at the bottom of this
message.)
In my testing, I just put a do-loop in that ties up the
BeginReceive thread for a couple of seconds to simulate a
long database run. So, my first request comes in fine,
tracks all the way through to the 'processing' stage. I
send in a second request and it goes ok, but the third
request does not get processed until my simulation gets
finished.. now this is EXACTLY what I'm supposed to be
avoiding, right?
Multi-threading is a real pain to debug, of course, but I
managed to watch the thread ID's for this operation, and
indeed, as expected, they are all starting on separate
threads.... Why I asked the question about when are they
released, is because I'm guessing the reason it stops on
the third call is it has run out of threads. (just a
guess.)
Could this have anything to do with the new worker threads
being created inside another worker thread? I
shouldn't... Or is it all the ManualResetEvents I'm using?
Any help or comments would be appreciated. Here is the
code:
---------------------------------------------------------
Public Sub Listen(ByVal State As Object)
Try
' get the localendpoint
Dim Socket As New Socket
(AddressFamily.InterNetwork, SocketType.Stream,
ProtocolType.Tcp)
'open the port and start listening
Socket.Bind(BS3.Common.GetLocalEndPoint
(Port))
Socket.Listen(200)
While True
Stopper1.Reset()
'wait for something to arrive
Socket.BeginAccept(New AsyncCallback
(AddressOf RequestReceived), Socket)
Stopper1.WaitOne()
End While
End Sub
Private Sub RequestReceived(ByVal AR As
IAsyncResult)
Try
Receiving1 = True
Stopper1.Set() 'allow main thread to
continue and handle next incoming request
Dim Socket1 As Socket = CType
(AR.AsyncState, Socket)
'extract the sending socket
Dim Socket As Socket = Socket1.EndAccept
(AR)
Dim MH As New MessageHolder
MH.WorkSocket = Socket
Stopper2.Reset()
'start getting the message
Socket.BeginReceive(MH.Buffer, 0,
MH.BufferSize, 0, AddressOf ReadRequest, MH)
Stopper2.WaitOne()
End Sub
Private Sub ReadRequest(ByVal AR As IAsyncResult)
Dim mysocket As System.Net.Sockets.Socket
Try
Receiving2 = True
Stopper2.Set()
Dim MH As MessageHolder = CType
(AR.AsyncState, MessageHolder)
' extract the sending socket
mysocket = MH.WorkSocket
Dim M As Byte()
' Read data from the server
Dim bytesRead As Integer =
mysocket.EndReceive(AR)
If bytesRead > 0 Then
' There might be more data, so store
the data received so far.
MH.MS.Write(MH.Buffer, 0,
bytesRead) 'appends data to the memorystream
If EndOfMessage(M()) then
Dim Response() as byte =
Ascii.GetBytes("Here is my response.")
'simulate database run here
Dim n As Date = Now
Do Until n < DateAdd
(DateInterval.Second, -10, Now)
Loop
' Send response
sendDone.Reset()
mysocket.BeginSend(Response,
0, Response.Length, 0, AddressOf SendCallback, mysocket)
sendDone.WaitOne()
End If
Else
'not finished, get more
mysocket.BeginReceive(MH.Buffer,
0, MH.BufferSize, 0, AddressOf ReadRequest, MH)
End If
End If
End Sub
Private Sub SendCallback(ByVal ar As IAsyncResult)
Try
CType(ar.AsyncState,
System.Net.Sockets.Socket).EndSend(ar)
Catch ex As Exception
CallBack.Invoke(CallBackEventTypes.Error,
ex.Message, ex.StackTrace)
Finally
sendDone.Set()
End Try
End Sub 'SendCallback
End Class
I haven't ever seen anything in the docs