Taking a snapshot causes .Net application to crash

rsctang

Hello all,

I'm trying to perform a memory analysis using "before, during and after" snapshots. The .Net application I'm working with calls unmanaged C code.

Here is the scenario:

I start ANTS 4 Memory Profiler.
Take a memory snapshot immediately after loading in the application.
I start my "calculator" to process information.
After about 30 minutes, I wanted to take snapshot to compare against the baseline.
Every time I do that, my .Net application crashes with a window stating:

Title: Microsoft Visual C++ Runtime Library
Runtime error!
Program C:\... ... (a partial path on my machine which looks like it points to the application location, it gets cut off so I can't see the full path)

Any ideas what I'm doing wrong?


Cheers,
Robert

Brian Donahue

Hi Robert,

Have you also tried this on the 4.1 Beta mentioned at the top of the forum? I have noticed that the 4.0 core can throw a similar C runtime error; something about a stack issue. I'd say update to 4.1 and see if it still happens.

Brian Donahue

Oops -- I just realized you are having this problem with the memory profiler. My runtime exception happened on the performance profiler.

I suppose you could still try upgrading anyway.

rsctang

Nope, didn't work. I still experience the same C++ runtime exception.

James Moore

Hi Robert,

What is your applications memory usage at the time ANTS Profiler crashes? How much memory do you have installed in your machine?

Thanks,

James

rsctang

The good news is that after making some memory usage modifications, I'm not able to successfully take a snap shot without crashing ANTS.

From Process Explorer at the time that I take a snapshot.

Private bytes: 451,000K
Peak Private bytes: 540,000K
Virtual Size: 819,000K

My total system memory is 2GB.



When ANTS was crashing, I think the Virtual Size was closer to 1,500,000K.


Is there a certain limit that I should be aware of, so that I can avoid this situation in the future? Or perhaps some general knowledge that can be passed along?


Thanks,
Robert

JasonC

Hi Robert. Sorry about the long delay in getting back to you!

There is no precise limit to how much memory ANTS Memory Profiler can cope with - it depends on the type of objects in memory. But it is about 500mb to 700mb - typically about 600mb. Adding, or removing, memory from your machine won't change this limit.

On an x64 machine I've found you can profile a program that uses 4Gb of memory with no issues.

We will be making a new memory profiler for H1 2009 that will deal with these memory limitations.

rsctang

Thanks for the info Jason.

I'll keep that limitation in mind and will look forward to the 1H '09 release.