R.,

I have managed to reproduce the problem; and, it appears that there indeed is a memory leak inside the component, related to “writes”. I have used recent build of COM Version 5.02.

I then attempted to find the cause of it, and spent good amount of time on it, but so far unsuccessful. It certainly can be found; however, I have also tried to use the Beta of Version 5.10, and the leak is NOT present in this new version.
[.....]

Best regards,
<span style="font-family: "Arial","sans-serif"; color: #1f497d; font-size: 10pt">Zbynek Zahradnik

<span style="font-family: "Tahoma","sans-serif"; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'">From:<span style="font-family: "Tahoma","sans-serif"; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'"> R.
Sent: Wednesday, May 25, 2011 5:06 PM
To: Zbynek Zahradnik
Subject: RE: Data-COM memory leak

Zbynek,

I have confirmed with the customer that they are using task manager to monitor the application process.

R.

<span style="font-family: "Tahoma","sans-serif"; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'">From:<span style="font-family: "Tahoma","sans-serif"; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'"> R.
Sent: Monday, May 23, 2011 3:39 PM
To: Zbynek Zahradnik
Subject: RE: Data-COM memory leak

Zbynek,

As far as I can tell he is just using task manager to monitor the application memory use (OPcTest.exe). I will double check with him.

R.

R.,

I will try to create something like you have suggested. [.....]

Can you figure out how the customer came to conclusion that there is a memory leak? I.e. what tool and what measurement is he using (task Manager? Performance Counters?). Which process is he monitoring and which does show the leak? (the user application? Or EOPCDAL.EXE? Both? Or is it just one process since in-process component is used?)

Thank you
<span style="font-family: "Arial","sans-serif"; color: #1f497d; font-size: 10pt">Zbynek Zahradnik

<span style="font-family: "Tahoma","sans-serif"; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'">From:<span style="font-family: "Tahoma","sans-serif"; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'"> R.
Sent: Monday, May 23, 2011 2:47 PM
To: Zbynek Zahradnik
Subject: Data-COM memory leak

Zbynek,

One of the Vc++ customers I have been working with is still insisting that the Data-Com WriteMultipleITemValue method is leaking memory. I have attached the project he sent that does reproduce the problem. He has tried implementing to same code sample that you sent to me before. He does however, have a lot of other things going on in the application and I believe the issue is somewhere else in his application.

My thought was to create a sample project showing just the WriteMultipleItemValue method that I could send to him and have him run to demonstrate that the memory leak is not with the OPC Data-COm library itself, and therefore must be somewhere else in his application. [....] attempted to do this, but have not been successful in VC++.

....

R.