Memory leak in daMetaData.TdaMetaData.GetFieldNamesFromDataSet

rbuser

Hi,

I am using a unit called MemCheck.Pas

(http://v.mahon.free.fr/pro/freeware/memcheck/)

while developing to check for leaks.

One reported leak is,

TdaMetaData.GetFieldNamesFromDataSet.


lFields := TList.Create;

GetFieldsFromDataSet(aMetaTable, lFields);

...

lFields.Free;

But the contents of lFields are objects and are not destroyed by the TList.

The is RBuilder 6.03. I don't know if I should be patching the code
myself when I come across leaks. Will there be any updates for version
6? Should I correct the leaks and/or report them?

Best regards,

Michel

nicocizik

Hi Michel,

Thanks for the information.

Please send us an example of the code you are using to cause the leak and we
will test with ReportBuilder 7.02 to see if it still exists and possibly fix
it.

--

rbuser

Hi Nico,

The code is quite huge. I created DADE classes for ODBC access and
testing on a database with more than 110 tables.

The leak is very simple,

In TdaMetaData.GetFieldsFromDataSet a field is created and added to the
aList parameter:

aFields.Add(lField);

But since aFields is simply a TList, it does not destroy it items.


Then in TdaMetaData.GetFieldNamesFromDataSet a list is created then
destroyed, but the fields inside the list are not destroyed:


lFields := TList.Create;

GetFieldsFromDataSet(aMetaTable, lFields);
...
lFields.Free;

I can correct the leak if you want, it is just a matter of iterating
though lFields, but I don't want to have a different code base.

Do you want me to correct the leaks I find and send you the changes?

If you prefer I have also attached the call stack if you prefer to look
into this directly.

Best regards,

Michel

Call stack:
Leak #0 - 11 occurence(s) - CLASS TdaMetaField, Size: 32, allocated at
0030A26B Module daMetaData.pas Routine
TdaMetaData.CreateMetaFieldFromDataSetField Line 853
TdaMetaField call stack -1 : 00309DA3 Module daMetaData.pas Routine
TdaMetaData.GetFieldsFromDataSet Line 704
call stack -2 : 00309EA1 Module daMetaData.pas Routine
TdaMetaData.GetFieldNamesFromDataSet Line 731
call stack -3 : 0030A358 Module daMetaData.pas Routine
TdaMetaData.ValidateFieldNames Line 883
call stack -4 : 00309C01 Module daMetaData.pas Routine
TdaMetaData.GetFields Line 653
call stack -5 : 00313F26 Module daSQL.pas Routine
TdaSQL.CreateFieldsForTable Line 2714
call stack -6 : 00313CEB Module daSQL.pas Routine
TdaSQL.CreateAvailableFieldList Line 2621
call stack -7 : 003196F3 Module daSQL.pas Routine
TdaSQL.SyncFields Line 6626
call stack -8 : 00319960 Module daSQL.pas Routine
TdaSQL.SyncSelectFields Line 6750
call stack -9 : 003156BD Module daSQL.pas Routine
TdaSQL.GetAvailableSelectFieldCount Line 3787
call stack -: : 0034DAF7 Module daQueryWizard.pas Routine
TdaWizardFieldPage.GetAvailableChildCount Line 2106
call stack -; : 0034C63B Module daQueryWizard.pas Routine
TdaWizardDualListPage.SQLToControls Line 1317
call stack -< : 0034DA37 Module daQueryWizard.pas Routine
TdaWizardFieldPage.SQLToControls Line 2062
call stack -= : 0034B8F4 Module daQueryWizard.pas Routine
TdaWizardPage.Activate Line 1023
call stack -> : 0034B4BE Module daQueryWizard.pas Routine
TdaQueryWizardDialog.ActivatePage Line 824
call stack -? : 0034B6C2 Module daQueryWizard.pas Routine
TdaQueryWizardDialog.btnNextClick Line 922
call stack -@ : 000399F4 Routine TControl.Click
call stack -A : 00031401 Routine TButtonControl.WndProc
call stack -B : 0003C164 Routine DoControlMsg
call stack -C : 0004F36C (no debug info)
call stack -D : 0003BD1B Routine TWinControl.MainWndProc
call stack -E : 0004C782 Routine StdWndProc
call stack -F : 77A3A240 (no debug info)
call stack -G : 77A16B1D (no debug info)
call stack -H : 77A24F46 (no debug info)
call stack -I : 712F5DBD (no debug info)
call stack -J : 712F5CDC (no debug info)