Re: how to release memory back to os

From:

"Ben Voigt [C++ MVP]" <rbv@nospam.nospam>

Newsgroups:

microsoft.public.vc.language

Date:

Thu, 1 May 2008 13:02:09 -0500

Message-ID:

<uOOc5T7qIHA.4376@TK2MSFTNGP06.phx.gbl>

PvdG42 wrote:

"JoeB" <joe@kybert.com> wrote in message
news:ea79192d-1fdf-4e8a-9174-53ad77ae5875@e53g2000hsa.googlegroups.com...

Hi,

When doing lots of new / delete combinations, the app shows as not
releasing the memory.

I know there is an OS function that releases application memory that
was deleted by delete[] back to the OS, as delete[] does not truely
release it back to the OS.

I cant remember the function name! Anyone?

What do you mean by "the app shows as not releasing the memory"?

He means it isn't releasing the memory.

If you're monitoring app resource use, and don't see a reduction, it's
probably because the OS has no need for it while you are monitoring.
Have you tried running (and monitoring ) your app in a busy
environment, launching other apps while you monitor?
I would suspect you won't "see" a reduction until the OS reallocates
the memory to another app or process, but that's an assumption on my
part. You're correct that delete and delete [] only notify that the
cited memory is available for reallocation.

The memory remains part of the private process heap and is only available to
be reused within the same process.

http://msdn.microsoft.com/en-us/library/aa366711(VS.85).aspx
"Once the pages are committed, they are not decommitted until the process is
terminated or until the heap is destroyed by calling the HeapDestroy
function."