ContextSwitch Deadlock - Timer infinite loop.

[adshocker]

Hi,

I need to create an application that will check certain records from the database and then do some processing on these records. These needs to be done every few seconds. I have now a console application that does this and used Timer class for the loop. Problem I'm getting is that I get the ContextSwitch Deadlock error.

Imports System.Data.OracleClient

Module Standard

    Private ORACLEXE_OracleConnection As New OracleConnection
    Private ORACLEXE_OracleConnectionStringBuilder As New OracleConnectionStringBuilder
    Private APPCONCURRENTREQUEST_DataTable As New DataTable
    Private APPCONCURRENTREQUEST_DataAdapter As New OracleDataAdapter
    Private APPCONCURRENTREQUEST_SelectCommand As New OracleCommand
    Private APPCONCURRENTREQUEST_UpdateCommand As New OracleCommand

    Private Function ExecutableFile(ByVal intProgramId As Integer) As String
        Dim strExecutableFile As String = String.Empty
        Dim drExecutableFile As OracleDataReader
        Dim selExecutableFile As New OracleCommand

        With selExecutableFile
            .CommandType = CommandType.Text
            .CommandText = "select ad.directory_path || '\' || se.executable_file_name " _
                         & "  from fnd_concurrent_programs scp" _
                         & "     , fnd_executables se" _
                         & "     , fnd_executable_types st" _
                         & "     , fnd_applications sa" _
                         & "     , all_directories ad" _
                         & " where scp.executable_id = se.executable_id" _
                         & "   and se.executable_type_code = st.executable_type_code" _
                         & "   and se.application_id = sa.application_id" _
                         & "   and ad.directory_name = sa.application_base || st.executable_base" _
                         & "   and scp.concurrent_program_id = :concurrent_program_id"
            .Parameters.AddWithValue("concurrent_program_id", intProgramId)
            .Connection = ORACLEXE_OracleConnection
        End With

        drExecutableFile = selExecutableFile.ExecuteReader

        Do While drExecutableFile.Read
            strExecutableFile = drExecutableFile.GetString(0)
        Loop

        Return strExecutableFile
    End Function

    Private Sub Check()
        ' For each row, print the values of each column. 
        Dim row As DataRow

        For Each row In APPCONCURRENTREQUEST_DataTable.Rows
            Console.WriteLine(ExecutableFile(row("CONCURRENT_PROGRAM_ID")))
        Next row
    End Sub


    Sub Main()
        Try
            With ORACLEXE_OracleConnectionStringBuilder
                .DataSource = "XE"
                .UserID = "USER"
                .Password = "pass"
            End With

            With ORACLEXE_OracleConnection
                .ConnectionString = ORACLEXE_OracleConnectionStringBuilder.ConnectionString
                .Open()
            End With

            With APPCONCURRENTREQUEST_SelectCommand
                .CommandType = CommandType.Text
                .CommandText = "select * from fnd_concurrent_requests where phase_code = 'P' order by requested_start_date"
                .Connection = ORACLEXE_OracleConnection
            End With

            With APPCONCURRENTREQUEST_UpdateCommand
                .CommandType = CommandType.Text
                .CommandText = "update fnd_concurrent_requests set phase_code = 'R' and pid = :pid where request_id = :request_id"
                .Connection = ORACLEXE_OracleConnection
            End With

            With APPCONCURRENTREQUEST_DataAdapter
                .SelectCommand = APPCONCURRENTREQUEST_SelectCommand
                .UpdateCommand = APPCONCURRENTREQUEST_UpdateCommand
                .Fill(APPCONCURRENTREQUEST_DataTable)
            End With

            Dim timerStandard As New Timers.Timer
            With timerStandard
                '.AutoReset = True
                .Interval = 10000
                AddHandler timerStandard.Elapsed, AddressOf timerStandard_Tick
                .Start()
                Console.ReadKey()
            End With

        Catch ex As Exception
            ORACLEXE_OracleConnection.Close()
            ORACLEXE_OracleConnection.Dispose()

        Finally
            ORACLEXE_OracleConnection.Close()
            ORACLEXE_OracleConnection.Dispose()

        End Try

    End Sub

    Private Sub timerStandard_Tick(ByVal sender As Object, ByVal e As System.Timers.ElapsedEventArgs)
        Console.WriteLine("Tick")
        Check()
    End Sub

End Module

How do I fix this error? It doesn't occur until for about a minute or so.

Thanks.

[dunfiddlin]

From the horse's mouth .... http://msdn.microsoft.com/en-us/library/ms172233.aspx

[adshocker]

From the horse's mouth .... http://msdn.microsoft.com/en-us/library/ms172233.aspx

Ok. Thanks.

I got a solution from a link on that article..

http://msdn.microsoft.com/en-us/library/d21c150d.aspx

Followed these steps.

However, disabling the hosting process can affect performance. You can avoid the need to disable MDAs by preventing Visual Studio from displaying the MDA dialog box whenever an MDA notification is received. To do that, click Exceptions on the Debug menu, expand the Managed Debugging Assistants list, and then select or clear the Thrown check box for the individual MDA.

Seems to be working fine now. I also check the CPU Usage and it doesn't go beyong 10%. Hopefully that solves it.