.net - vb.Net- navngivne rør - NamedPipeServerStream - StackOverflowException

Indlæg af Hanne Mølgaard Plasc

Problem



Jeg forsøger at bruge navngivne rør til at kommunikere mellem en Windows-service og en WPF-applikation, begge skrevet i VB.Net. Windows-tjenesten kører altid.


Men efter flere timer med at køre WPF ansøgningen kastes en StackOverflowException.


PipeServerThread() i WPF-applikationen er den eneste funktion, der kaldes gentagne gange i den administrerede stak på tidspunktet for undtagelsen (jeg sporede dette ned ved hjælp af WinDbg).


Tjenesten indeholder NamedPipeClientStream, Programmet indeholder NamedPipeServerStream.


Når klienten og serveren kommunikerer, læser serveren det endelige klientrespons efter nogle få kontroller, og overfører klientstrengen til en funktion andetsteds i koden.


Rørserveren spyles derefter, lukkes og anbringes.


PipeServerThread() kaldes derefter igen for at oprette en anden pipeserver til kommunikation. Bemærk denne PipeServerThread () kaldes gentagne gange.


Kan nogen kaste lys over hvad i koden til sidst forårsager StackOverflowException at forekomme?


PipeServer:


Dim PipeServers(1) As Thread
PipeServers(1) = New Thread(AddressOf PipeServerThread)
PipeServers(1).IsBackground = True
PipeServers(1).Start()

Private Sub PipeServerThread()

    Dim ps = New System.IO.Pipes.PipeSecurity

    Try
        ps.AddAccessRule(New System.IO.Pipes.PipeAccessRule("Users", System.IO.Pipes.PipeAccessRights.FullControl, System.Security.AccessControl.AccessControlType.Allow))
        ps.AddAccessRule(New System.IO.Pipes.PipeAccessRule("CREATOR OWNER", System.IO.Pipes.PipeAccessRights.FullControl, System.Security.AccessControl.AccessControlType.Allow))
        ps.AddAccessRule(New System.IO.Pipes.PipeAccessRule("SYSTEM", System.IO.Pipes.PipeAccessRights.FullControl, System.Security.AccessControl.AccessControlType.Allow))

        Dim pipeserver = New System.IO.Pipes.NamedPipeServerStream("testpipe", Pipes.PipeDirection.InOut, 10, Pipes.PipeTransmissionMode.Byte, Pipes.PipeOptions.None, 4024, 4024, ps)

        Debug.WriteLine("Pipeserver waiting for connection")
        pipeserver.WaitForConnection()
        Try
            'Debug.WriteLine("Pipeserver now within Try block.")
            Dim ss As New StreamString(pipeserver)
            'This server writes to pipe immediately on connection
            Debug.WriteLine("Server now writing to Pipe")
            ss.WriteString("Hello Client. Who are you?")                                            'Action 1 - server writes to Pipe

            'Response from client is read
            Dim ClientName As String = ss.ReadString                                                'Action 4 - server reads from Pipe
            Debug.WriteLine("Client's name is: " & ClientName)
            If ClientName = "PipeWriterService" Then
                'The client is the PipeWriterService
                'Tell it what state is being requested
                ss.WriteString(RequestedCommState)                                                  'Action 5 (if) - server writes to Pipe
            Else
                'The client is someting else
                ss.WriteString("wrong client")                                                      'Action 5 (else) - server writes to Pipe
            End If

            Dim ClientResponse As String = ss.ReadString()
            Debug.WriteLine("Server has read client Response as: " & ClientResponse)                'Action 8 - server reads from Pipe
            DeviceInfo.Dispatcher.BeginInvoke(Windows.Threading.DispatcherPriority.Normal, New OneArgDelegate3(AddressOf ProcessPipeString), ClientResponse)
        Catch ex As Exception
            Debug.WriteLine("Error is Server Try block: " & ex.Message)
        End Try
        pipeserver.Flush()
        pipeserver.Close()                                                                          'Action 9 - server closes Pipe
        pipeserver.Dispose()
        Debug.WriteLine("PipeServer now closed")
    Catch ex As Exception

    End Try

    Call PipeServerThread()
End Sub


PipeClient:


    Private Sub PipeWriter(StringToWrite As String)
    Dim pipeClient As New NamedPipeClientStream(".", "testpipe", PipeDirection.InOut, PipeOptions.None)
    Try
        pipeClient.Connect(50)
        Dim ss As New StreamString(pipeClient)
        'Once a connection is established, Server will write to pipe first
        'This is read by the client in the line below
        Debug.WriteLine("First string from Server: " & ss.ReadString())                             'Action 2: Client Reads from Pipe
        'Server is now waiting. This client responds with its name
        ss.WriteString("PipeWriterService")                                                           'Action 3: Client Writes to Pipe
        'Server will respond again
        'This is read by the client in the line below
        RequestedCommState = ss.ReadString()                                                    'Action 6: Client reads from Pipe
        Debug.WriteLine("Second string from Server: " & RequestedCommState)
        'This response contains the desired 3G comm status from the server
        'Server is now waiting. This client responds with whatever it wants to say to server
        ss.WriteString(StringToWrite)                                                               'Action 7: Client writes to Pipe
    Catch ex As Exception
        Debug.WriteLine("Error in PipeWriter. Error is: " & ex.Message)
    End Try

End Sub

Bedste reference