memory usage

Author

Message

Michael Philbrick

Posted: 03/14/2005 1:29:24

Sergey,

I am having an issue similar to the "memory usage problem" newsgroup post

of Friday 28 Feb 2003.

Consider the following code:

procedure TfmRecordBreaker.Button1Click(Sender: TObject);

rvComm.Clear;

rvComm.Format;

rvComm.InsertRVFFromFileEd('c:\test.rvf');

end;

This is the simplest I could get the code to reproduce the problem. In my

actual code, I call LoadRVFFromStream multiple times to build the main document,

headers and footers for print preview. I noticed that each time the document

was displayed, my application increased its Mem Usage in Windows Task Manager

by 40-150K. The values just continued to rise and eventually the performance

of the LoadRVFFromStream method suffered, taking 5-10 seconds to run.

I noted in the newsgroup thread that you could not find any memory leaks.

I then decided to try this with your RVEditDemo.exe application. I opened

the sample document, readme.rvf, about 30 times in a row, sometimes clearing

the document in between loads, sometimes not (this didn't seem to make a

difference).

Watching the memory usage I noticed that it would creep up two or three times,

hold steady for another 4-5 cycles, then creep up again for 2-3 cycles in

a row. The end result is that I noticed the same memory creep in your sample

application, usually 10-40K at a time.

With my application it is magnified tremendously because I use a lot of RichViewEdit

componenents simultaneously.

I also noticed that when my print preview richviewedit controls were placed

on a modal form, where the form had to be created, opened and destroyed each

time I wanted to display the document, the "memory creep" disappeared. Therefore,

it appears that the additional memory that is being allocated is not actually

"lost" but is freed correctly when the component is destroyed.

This increased use of memory causes major performance issues the longer the

application is open, so a solution is very important.

Please let me know if you need any other information.

Michael Philbrick