FIX: Marshaling ADO Recordset Out-of-Process Causes Small Memory Leak (230487)

SYMPTOMS

When an ADO recordset is marshaled out-of-process from a COM server, a small leak in Private Bytes occurs in the COM server's process space.

This leak occurs when using either a disconnected ADO recordset or a recordset created with the RDS DataFactory if you are using versions of MDAC earlier than 2.1 sp2.

STATUS

This problem has been fixed in Microsoft Data Access Components 2.1 and later. You may download the latest version of Microsoft Data Access Components from the following site:

http://msdn.microsoft.com/library/default.asp?url=/downloads/list/dataaccess.asp

MORE INFORMATION

Steps to Reproduce Behavior

Create an Executable project in Visual Basic that will be the server application. Name the project LeakEXE, and within it, create a class module named LeakRS. Set a reference to the Microsoft ActiveX Data Objects Library. Use the following code within the LeakRS class:

Option Explicit

Function GetRS() As ADODB.Recordset
Dim rs As ADODB.Recordset
    
    On Error Resume Next
    Set rs = New ADODB.Recordset
    rs.Fields.Append "x", adInteger
    rs.Open
    rs.AddNew
    rs.Fields(0).Value = 1
    rs.Update
    rs.MoveFirst
    Set GetRS = rs
    
End Function

Next, create a client project in Visual Basic, using the following code. Then, set a reference to the ActiveX EXE and to Microsoft ActiveX Data Objects Library.

Sub OutofProcLeak()
Dim x As New LeakEXE.LeakRS
Dim rs As ADODB.Recordset

For i = 0 To 200000
    Set rs = x.GetRS
    Debug.Print Str(i)
    DoEvents
Next

Set rs = Nothing