Session Manager in 15.2.69 stops working sometimes

[Alexandre Machado]

When you say you get an AV, where exactly does it happen? Do you have the call stack (the exception logger, if active, should contain all details about it).

We get an "Invalid Pointer Operation" in the TIWForm.Dispose calling inherited Dispose:

Code:

TIWForm.Dispose inherited dispose
[000000005EDE9A63] System.ErrorAt
[000000005EDE9AB1] System.Error
[000000005EDE97D1] System.@FreeMem
[000000005EE1FFEA] System.SysUtils.StrDispose
[000000005F10BEC9] Vcl.Controls.TControl.Destroy
[00000000607CDA64] IWVCLBaseControl.TIWVCLBaseControl.Destroy (Line 176, "IWVCLBaseControl.pas")
[000000005EDEEED8] System.TObject.Free
[00000000607AACFB] IWContainer.TIWContainer.Dispose (Line 545, "IWContainer.pas")
[00000000607CE8E0] IWFormDsn.TIWModuleDsn.Dispose (Line 139, "IWFormDsn.pas")
[00000000607D12CD] IWBaseForm.TIWBaseForm.Dispose (Line 494, "IWBaseForm.pas")
[000000005FE6F569] IWBaseHTMLForm.TIWBaseHTMLForm.Dispose (Line 90, "IWBaseHTMLForm.pas")
[00000000607BFB5B] IWForm.TIWForm.Dispose (Line 523, "IWForm.pas")
[000000006064A8B3] UnitCaiwBaseForm.TIWCaiwBaseForm.Dispose (Line 1653, "UnitCaiwBaseForm.pas")
[000000005F1E3C66] IWVCLBaseContainer.TIWBaseContainer.Destroy (Line 228, "IWVCLBaseContainer.pas")
[00000000607D0E7D] IWBaseForm.TIWBaseForm.Destroy (Line 394, "IWBaseForm.pas")
[00000000607BF0CF] IWForm.TIWForm.Destroy (Line 361, "IWForm.pas")
[00000000606496D4] UnitCaiwBaseForm.TIWCaiwBaseForm.Destroy (Line 1541, "UnitCaiwBaseForm.pas")
[000000005EDEEED8] System.TObject.Free
[000000005EF25C8F] System.Classes.TComponent.DestroyComponents
[000000005EF2547F] System.Classes.TComponent.Destroy
[00000000607D9C0E] IWApplication.TIWApplication.Destroy (Line 819, "IWApplication.pas")
[000000005EDEEED8] System.TObject.Free
[000000005F1D75C7] IWServerControllerBase.TSessionTimeoutThread.DoExecute (Line 1658, "IWServerControllerBase.pas")
[000000005EFABE2C] IW.Common.Threads.TIWTimedThread.Execute (Line 228, "IW.Common.Threads.pas")
[000000005EF23263] System.Classes.ThreadProc
[000000005EDF224D] System.ThreadWrapper
[00007FFC896C4DE0] BaseThreadInitThunk
[00007FFC8ABBED9B] RtlUserThreadStart
: Invalid pointer operation

Hi Dr. Bob,

From your call stack it's clear to me that the exception affected the session timout thread. I'll have to revisit the code of this version and check why it happened. At least the call stack is very clear about this, which is good..

It there anything special regarding this form in your application? Maybe some dynamic components being created/destroyed or changing parents at runime (e.g. IWGrids)?

TIWCaiwBaseForm

It would be good to also understand why the exception happened. Seems that a TIWVCLBaseControl (any TIWControl descendant basically) raised that exception when being destroyed. It smells like it has been already destroyed previously, before the actual form destruction.

Thanks for the valuable information