C# Usage of GC and how to trace a Memory Leak

Question

I have a large C# server application, I'm interested in learning how the GC class works, and in particular what actions should I take to determine the source of a possible memory leak.

Are there any books on the subject, or is it not really that ellaborate?

Answer 1

To complement the answers above, there are more recent videos on Channel9 with Maoni Stephens (Principal developer for the GC on the CLR team at Microsoft) that walk you through basics of GC, what developers should look out for, how they should troubleshoot, and some of the tools you can use. I found the explanation of how the GC works and the concept of generations and roots really useful.

Here is the first part of a 3 episode series :

http://channel9.msdn.com/Shows/Defrag-Tools/Defrag-Tools-33-CLR-GC-Part-1

Answer 2

There is an excellent article by Rico Mariani: Tracking down managed memory leaks (how to find a GC leak). I used this technique often and is easy and efficient. And getting yourself familiar with a true debugger like Windbg is a bonus side benefit!

Answer 3

There is also the SciTech .NET Memory Profiler, our team has been using that successfully.

Answer 4

There are plenty of sources you can study.

I hope you don't miss basics:

• CLR via C# 3rd Edition by Jeffrey Richter

I think before you go with details about GC, try to understand how IDisposable and resource management is handled:

• Dispose, Finalization, and Resource Management. It pretty old but still awesome.

GC specific:

• Garbage Collection / Fundamentals of Garbage Collection
• Maoni's WebLog (Maoni Stephens is a software developer who spends her time implementing .NET's GC. In fact, she's been working on the GC since the early days of .NET.)
• Video: Maoni Stephens and Andrew Pardoe: CLR 4 Garbage Collector - Inside Background GC
• Video: Erik Meijer and Patrick Dussud - Inside Garbage Collection
• Drill Into .NET Framework Internals to See How the CLR Creates Runtime Objects
• Identify And Prevent Memory Leaks In Managed Code

Hope it helps to start.

Answer 5

Also not a book, but decent article. Memory Leak Detection in .NET

Answer 6

Not a book, but our team has used the ANTS Memory Profiler with pretty good success for tracking down managed memory leaks. Their support section and included help walks you through the process of tracking down different types of memory issues. This doesn't include specifics on the GC class itself, just how to track down common mistakes (event handler deregistration, static variables, etc.).