I have a simple subroutine (see below) which reads a table and populates the items of a combobox.  As the subroutine is executed, I'm watching the taskmanager and the memory in use increases; however, once I get to the Error_Exit: logic and start to close and dispose my memory variables, the memory is not released and does not decrease in the task manager.  Why is that?  Eventually, my program is giving me "Insufficient memory" errors.

****************************************************************************************

On Error GoTo Error_Handling

Dim cnn As New Odbc.OdbcConnection
Dim cmd As New Odbc.OdbcCommand
Dim rdr As Odbc.OdbcDataReader

cnn.ConnectionString = "dsn=" & accpac_companyid
cnn.Open()
cmd.Connection = cnn
cmd.CommandText = "select schedkey, scheddesc from cssktb order by schedkey"
rdr = cmd.ExecuteReader

Do While rdr.Read
    combo.Items.Add(rdr("schedkey").ToString.Trim)
Loop

Error_Exit:
    If Not IsNothing(rdr) Then
        rdr.Close()
        cmd.Connection.Close()
        cmd.Dispose()
        cnn.Close()
        cnn.Dispose()
    End If

    rdr = Nothing
    cmd = Nothing
    cnn = Nothing
Exit Sub

Error_Handling:
    Select Case Err.Number
    Case Else
        MsgBox("The following error occured in LoadSchedules()" & vbCrLf & Err.Description)
    End Select

Resume Error_Exit

You should try profiling with a memory profiler to see who is holding the objects, if actually somebody is holding them.

  I have a simple subroutine (see below) which reads a table and populates the items of a combobox.  As the subroutine is executed, I'm watching the taskmanager and the memory in use increases; however, once I get to the Error_Exit: logic and start to close and dispose my memory variables, the memory is not released and does not decrease in the task manager.  Why is that?  Eventually, my program is giving me "Insufficient memory" errors.

  ****************************************************************************************

  On Error GoTo Error_Handling

  Dim cnn As New Odbc.OdbcConnection
  Dim cmd As New Odbc.OdbcCommand
  Dim rdr As Odbc.OdbcDataReader

  cnn.ConnectionString = "dsn=" & accpac_companyid
  cnn.Open()
  cmd.Connection = cnn
  cmd.CommandText = "select schedkey, scheddesc from cssktb order by schedkey"
  rdr = cmd.ExecuteReader

  Do While rdr.Read
      combo.Items.Add(rdr("schedkey").ToString.Trim)
  Loop

  Error_Exit:
      If Not IsNothing(rdr) Then
          rdr.Close()
          cmd.Connection.Close()
          cmd.Dispose()
          cnn.Close()
          cnn.Dispose()
      End If

      rdr = Nothing
      cmd = Nothing
      cnn = Nothing
  Exit Sub

  Error_Handling:
      Select Case Err.Number
      Case Else
          MsgBox("The following error occured in LoadSchedules()" & vbCrLf & Err.Description)
      End Select

  Resume Error_Exit

I've tried profiling the code with AntsProfiler (and many others), but I
have NO IDEA what I'm looking at there.  Am I wrong in assuming the memory
in use should return to the value before the subroutine executes if all the
variables are terminated properly?

  You should try profiling with a memory profiler to see who is holding the objects, if actually somebody is holding them.

  --
  Miha Markic [MVP C#, INETA Country Leader for Slovenia]
  RightHand .NET consulting & development www.rthand.com
  Blog: http://cs.rthand.com/blogs/blog_with_righthand/
    I have a simple subroutine (see below) which reads a table and populates the items of a combobox.  As the subroutine is executed, I'm watching the taskmanager and the memory in use increases; however, once I get to the Error_Exit: logic and start to close and dispose my memory variables, the memory is not released and does not decrease in the task manager.  Why is that?  Eventually, my program is giving me "Insufficient memory" errors.

    ****************************************************************************************

    On Error GoTo Error_Handling

    Dim cnn As New Odbc.OdbcConnection
    Dim cmd As New Odbc.OdbcCommand
    Dim rdr As Odbc.OdbcDataReader

    cnn.ConnectionString = "dsn=" & accpac_companyid
    cnn.Open()
    cmd.Connection = cnn
    cmd.CommandText = "select schedkey, scheddesc from cssktb order by schedkey"
    rdr = cmd.ExecuteReader

    Do While rdr.Read
        combo.Items.Add(rdr("schedkey").ToString.Trim)
    Loop

    Error_Exit:
        If Not IsNothing(rdr) Then
            rdr.Close()
            cmd.Connection.Close()
            cmd.Dispose()
            cnn.Close()
            cnn.Dispose()
        End If

        rdr = Nothing
        cmd = Nothing
        cnn = Nothing
    Exit Sub

    Error_Handling:
        Select Case Err.Number
        Case Else
            MsgBox("The following error occured in LoadSchedules()" & vbCrLf & Err.Description)
        End Select

    Resume Error_Exit

Well, no, if your combo is a global variable and you don't clear its items.

  I've tried profiling the code with AntsProfiler (and many others), but I
  have NO IDEA what I'm looking at there.  Am I wrong in assuming the memory
  in use should return to the value before the subroutine executes if all the
  variables are terminated properly?

    You should try profiling with a memory profiler to see who is holding the objects, if actually somebody is holding them.

    --
    Miha Markic [MVP C#, INETA Country Leader for Slovenia]
    RightHand .NET consulting & development www.rthand.com
    Blog: http://cs.rthand.com/blogs/blog_with_righthand/
      I have a simple subroutine (see below) which reads a table and populates the items of a combobox.  As the subroutine is executed, I'm watching the taskmanager and the memory in use increases; however, once I get to the Error_Exit: logic and start to close and dispose my memory variables, the memory is not released and does not decrease in the task manager.  Why is that?  Eventually, my program is giving me "Insufficient memory" errors.

      ****************************************************************************************

      On Error GoTo Error_Handling

      Dim cnn As New Odbc.OdbcConnection
      Dim cmd As New Odbc.OdbcCommand
      Dim rdr As Odbc.OdbcDataReader

      cnn.ConnectionString = "dsn=" & accpac_companyid
      cnn.Open()
      cmd.Connection = cnn
      cmd.CommandText = "select schedkey, scheddesc from cssktb order by schedkey"
      rdr = cmd.ExecuteReader

      Do While rdr.Read
          combo.Items.Add(rdr("schedkey").ToString.Trim)
      Loop

      Error_Exit:
          If Not IsNothing(rdr) Then
              rdr.Close()
              cmd.Connection.Close()
              cmd.Dispose()
              cnn.Close()
              cnn.Dispose()
          End If

          rdr = Nothing
          cmd = Nothing
          cnn = Nothing
      Exit Sub

      Error_Handling:
          Select Case Err.Number
          Case Else
              MsgBox("The following error occured in LoadSchedules()" & vbCrLf & Err.Description)
          End Select

      Resume Error_Exit

All you should need to do is call close on the reader and the connection.
After that the garbage collector should take care of the unused objects.

I'm a tad confused as to why you are using the old style VB 6 error
handling instead of using a Try Catch block. I'd try to run away as fast as
possible from using that type of error handling. It's clunky and doesn't
really give you very good information when you're trying to debug an error.

If worse comes to worse you'll probably need to get a memory dump and see
if there are a lot of uncollected/rooted objects in memory.

It's also possible that you are leaking objects somewhere else rather than
in the section of code you have displayed.
-------------------------------------
Chris Alton, Microsoft Corp.
SQL Server Developer Support Engineer
This posting is provided "AS IS" with no warranties, and confers no rights.
--------------------
the items of a combobox.  As the subroutine is executed, I'm watching the
taskmanager and the memory in use increases; however, once I get to the
Error_Exit: logic and start to close and dispose my memory variables, the
memory is not released and does not decrease in the task manager.  Why is
that?  Eventually, my program is giving me "Insufficient memory" errors.
Show quoteHide quote& Err.Description)
Show quoteHide quote

vs 20028 when??
Memory Leak Caused by Using DataTable.Select
Timeout expired on Insert
"@p5 : Byte array truncation to a length of 8000."
The DataTable / DataSet size