Zero Garbage Collector on .NET Core

Starting from .NET Core 2.0 coupling between Garbage Collector and the Execution Engine itself have been loosened. Prior to this version, the Garbage Collector code was pretty much tangled with the rest of the CoreCLR code. However, Local GC initiative in version 2.0 is already mature enough to start using it. The purpose of the exercise we are going to do is to prepare Zero Garbage Collector that replaces the default one.

Zero Garbage Collector is the simplest possible implementation that in fact does almost nothing. It only allows you to allocate objects, because this is obviously required by the Execution Engine. Created objects are never automatically deleted and theoretically, no longer needed memory is never reclaimed. Why one would be interested in such a simple GC implementation? There are at least two reasons:Continue reading

Note: This is a first entry of a new series about Microsoft .NET CLR internals. I encourage you to ask – the most interesting questions will become a similar posts in the future! This one was inspired by Angelika Piątkowska.

How does Object.GetType() really work?

Extending this question: How an object knows what type it is? Is it the compiler or the runtime that knows that? How this is related to the CLR? As C# is statically and strongly typed, maybe the method call GetType() does not really exist, and the compiler can replace it with the appropriate result already at compile time?Continue reading


Today I would like to walk you through the process of compiling, running and debugging of .NET Core – that is the open source version of .NET environment. Let’s go to the answer to the simple question straight away…

What for?

In order to push the boat out. We got the source of .NET! Why do we need to compile it? In order to tamper, change, analyze, damage it – so that in the end up at Pull Request and record ourselves in Hall of Fame as our code will go to millions of computers all over the world!

Even if we don’t have such ambitious plans, isn’t it just fun to look inside .NET? Of course, it’s not the code of commercial .NET in one-to-one relation. However, the most of the inner part is the same, so there is plenty to play with. .NET foundation site states it plainly:Continue reading