Chris Lyon's WebLog

One commonly misunderstood feature is the relationship between disposable objects (Objects that implement the IDisposable interface) and the GC. I know there are a lot of online resources about patterns and best practices but there is still a lot of confusion...

As you may know, there are different GC modes to choose from depending on the type of application you’re using: Server GC, Workstation GC, and Concurrent GC ( more info ). These settings are process-wide, set at the beginning of the process. Once the...

Due to the positive response on my previous entry on Dispose, I thought I'd write another, this time on what one should and shouldn't do with a Dispose method. Dispose should contain code to release any unmanaged resources associated with the object's...

One common question I see asked is the differences between server and workstation GC, and how Concurrent GC fits in. Server GC is only available on multi-proc machines. It creates one GC heap (and thus one GC thread) for each processor, which are collected...

I keep a GC folder in my Favorites full of links to articles and blog posts about the .NET GC. I thought it would be a good idea to consolidate them all into one blog post, for handy reference. These are the articles I most often post as answers to questions...

A GCHandle is a struct used to hold onto a managed object to be used by unmanaged code. With a GCHandle you can (among other things): Prevent an object from being garbage collected if unmanaged code has the only live reference to it Pin an object in memory...

I've heard several people asking why GCHandle doesn't implement IDisposable, considering it wraps an unmanaged resource (a handle) and needs to be explicitly freed (using GCHandle.Free()). Before I explain the reason, I want to give a little background...

GC Myth: setting an object's reference to null will force the GC to collect it right away. GC Truth: setting an object's reference to null will sometimes allow the GC to collect it sooner. As much as you may want to, you can't guarantee the GC will collect...

One of the most common “bugs” I read about on the Microsoft public newsgoups is the fact that the runtime does not automatically choose Server GC mode on a multi-proc machine, or server OS. If the server OS is running on a single-proc machine then the...

I posted previously about how to set the GC mode your application. So now that you’re running your app, how do you know it’s running in that GC mode? If you’re using v1.0 or v1.1, the CLR loads a different dll based on which GC mode (mscorwks.dll for...

I’m sure many of you have heard the term “object resurrection” with respect to the GC. It’s an interesting (but not very useful) way to illustrate object lifetimes and the role of finalization versus garbage collection. Basically, it’s a way to reference...

In Orcas we’ve added an overload to System.GC.Collect(): void System.GC.Collect(int generation, System.GCCollectionMode mode) Where generation is the highest generation to collect (from 0 to System.GC.MaxGeneration) and mode can be: Default...

A great post on the BCL Team Blog by Brian Grunkmeyer about SafeHandles . He explains in-depth the topic I brought up ago a few posts ago about mitigating race conditions with the finalizer. Definitely worth a read.

The WeakReference class has the property IsAlive. The problem with it, is that you can only trust it if it returns false. While a WeakReference points to an object that is either live (reachable), or garbage (unreachable) that has not yet been collected...

Maoni posted Part 2 to Using the GC Efficiently. A very in-depth article about Server, Workstation and Concurrent GC. Check it out.

Joe Duffy has posted the revised Dispose, Finalization, and Resource Management Design Guideline . It's a great (and long) read. Check it out!

The purpose of GC.KeepAlive(Object) is to tell the GC not to collect an object until a certain point. For example: class MyObject { ~MyObject() { Console.WriteLine(“MyObject Finalized”); } public static void Main() { MyObject obj = new MyObject...

Hi! My name is Chris Lyon, and I'm a tester for the .NET Garbage Collector. The GC is one of the least-understood components of the CLR, and I hope to try to help our customers better understand it. Topics I hope to cover: General overview of how the...

The WeakReference class has two public constructors. public WeakReference(Object target) public WeakReference(Object target, bool trackResurrection) The first parameter is pretty obvious. It’s the object you want the WeakReference to reference...

The Orcas March CTP is out, and what does that mean for the Garbage Collector? The GC team has been concentrating on three areas for this release: Bug fixes. For Orcas, we’ve fixed several premature Out of Memory bugs, improved stability in certain...

Tired of the same old “garbage”? Do you want to be the tester for one of the most challenging technical areas of the Common Language Runtime (CLR) and work with the industry’s top developers, architects, and distinguished engineers? The CLR team is looking...