ExcelApp.WorkBooks.Open() memory leak

[GringoStarr 0]

I've written a procedure that opens .csv files and saves them
in an excel workbook. It works fine, however, I noticed that
memory is not being released. After some checking I found that
it is the ExcelApp.Workbooks.Open() function that's not releasing
memory. Here's the code:

for var CSVItem in CSVDataDict do with CSVItem do begin
  const LineCount = Value.Count - 2;
  const CSVFile = Path + Key + '.csv';
  var ColumnWidths : IntegerArray;

  TFile.WriteAllText(CSVFile, Value.GetText, Encoding);
  SrcWorkBook := ExcelApp.Workbooks.Open(CSVFile, EmptyParam, EmptyParam, 
                 EmptyParam, EmptyParam, EmptyParam, EmptyParam, EmptyParam,
                 EmptyParam, EmptyParam, EmptyParam, EmptyParam, EmptyParam, 
         EmptyParam, EmptyParam, LCID);
  ExcelWorkSheet := SrcWorkBook.Worksheets[1] as _Worksheet;
  CalculateColumnWidths(Key, ColumnWidths, Value);
  SetWorkSheetAttributes(Key, ExcelWorkSheet, ColumnWidths, LineCount);
  Count := ExcelWorkBook.Worksheets.Count;
  ExcelWorkSheet.Copy(EmptyParam, ExcelWorkBook.Worksheets[Count], LCID);
end;

I'm using Excel2010 in my application. I'm kind of new to Delphi Pascal
and it's hard to find good examples on how to use Excel Automation. Maybe
I'm not doing it right or is there a problem with memory leaks in the 
Workbooks.Open() function?

[David Heffernan 2300]

How are you detecting that the memory has been leaked? 

[PeterBelow 218]

Your code snippet is too incomplete to say for sure but are you ever freeing the SrcWorkbook and ExcelWorkSheet instances you get there? I don't remember whether these are interface types or class wrappers, you have to check the source of the Excel2010 to see what they are.  If the two variables are defined in a local scope and are interface types they would be released automatically but not if they are objects...

[Sherlock 632]

@GringoStarr Please refrain from posting the same question in different subforums for your own benefit. It will just divide attention.

[GringoStarr 0]

Sorry about that. I posted it to the wrong forum. I found out that it's not the WorkBooks.Open()

statement but TFile.WriteAllText(...). It's the Value.GetText statement, which I didn't expect.

[David Heffernan 2300]

We've no idea what Value is. How are you detecting that there's a leak. 

[GringoStarr 0]

Forgot to mention that. It's a TStringList. CSVDataDict is a TDictionary<String, TStringList>.

Running the for-loop

var TextData : String;
for var CSVItem in CSVDataDict do with CSVItem do begin
  TextData := CSVItem .GetText;
end

 

results in memory leakage. Removing the assignment statement inside the for-loop

there is no leakage.

[GringoStarr 0]

The leakage is detected when i close the application.

[GringoStarr 0]

I don't know why but the memory leakage disappeared when I use Value.Text instead of Value.GetText

in the statement TFile.WriteAllText(CSVFile, Value.GetText, Encoding).

[David Heffernan 2300]

We can't guess what the code is. We still don't know how you are detecting. 

[GringoStarr 0]

I don't know if you missed the last 3 posts I sent. The memory leakage is detected when

I close the application after running the for-loop. When you shut down the application a

window pops up with a long list of leaked memory blocks. Anyway, the problem is solved.

The leakage disappeared when I changed Value.GetText to Value.Text in the statement

 

TFile.WriteAllText(CSVFile, Value.GetText, Encoding);

inside the for-loop. Apparently, the expression Value.GetText is what caused the memory leaks.

Sorry for my sloppy posts.

[David Heffernan 2300]

Yes, but what is reporting the memory leak? There are lots of leak detection tools. If you use full fastmm then you can get allocation stack traces. 

 

It doesn't sound like you've really understood the issue. Normally Text would just map directly to GetText. But we still have no idea what Value is. 

 

This thread displays a deeper problem. That you think we can tell you what is happening with such incomplete details highlights the fact that you are also trying to solve the problem without those details. 

[Fons N 17]

 

On 9/22/2023 at 11:24 PM, GringoStarr said:

new to Delphi Pascal
and it's hard to find good examples on how to use Excel Automation

 

I found this website to be very helpful.

 

https://www.physiologyweb.com/delphi_code_examples/microsoft_excel_automation_with_delphi.html

 

[GringoStarr 0]

Thanks for your help.