Question

I’ve just been sorting out some memory leaks in my WPF application. To do so, I used the CLR profiler, as well as watching process statistics in Windows Task Manager. My basic test was to make sure that when a certain window was closed, it didn’t still hang around in memory.

I’m slightly new to windows development, and at first I was getting confused because in a simple test application, it seemed as if no matter what, my windows were always staying in memory after being closed. But I eventually worked out that this did not mean there was a memory leak, but just simply that they hadn’t been garbage collected yet. So I had to create a button in my main window hooked up to an event handler that contained code to manually force garbage collection. By manually garbage collecting, I could then complete my memory leak tests, and I got it all sorted.

But it got me thinking – is there ever a need to manually force garbage collection?

It pains me to watch my application’s memory consumption go up and up as I open and close windows. Of course, eventually, garbage collection automatically runs and it all gets sorted out. But it almost seems like a good idea to manually garbage collect after these heavy windows get closed. But is there any point? I get the feeling that testing aside, we are not supposed to force garbage collection – just let the system sort it out.

Thoughts appreciated.

Answer 1

Thanks for the feedback guys. I’ll go along with your advice and let the system take of care of what the system was designed to take care of!

I actually have since found a good answer to my question in a book I have on the .NET framework. It says:

The whole purpose of the .NET garbage
collector is to manage memory on our
behalf. However, in some very rare
circumstances, it may be beneficial to
programmatically force a garbage
collection using GC.Collect().
Specifically:

• When your application is about to enter into a block of code that you don’t
  want interrupted by a possible garbage
  collection.
• When your application has just finished allocating an extremely large number
  of objects and you wish to remove as
  much of the acquired memory as soon as
  possible.