To box or not to Box? That is the question!

Discussions on reddit, hacker news. Recently I’ve noticed that the Equal method from our ValueTuple (*) struct generates significant memory traffic (~1Gb). That was a bit of a surprise to me. This struct is well designed and was used pretty heavily in many performance critical scenarios. Here how the struct looks like: public struct ValueTuple<TItem1, TItem2> :…

5

Garbage collection and variable lifetime tracking

Here is a seemingly simple question for you: Is it possible that the CLR will call a finalizer for an instance when an instance method is still running? In other words, is it possible in the following case to see ‘Finalizing instance.’ before ‘Finished doing something.’? internal class GcIsWeird{    ~GcIsWeird()    {        Console.WriteLine(“Finalizing instance.”);    }     public int data = 42;    …

0

A common execution path optimization

Today I want to talk about one interesting optimization pattern that you may face in framework code or in high-performance libraries. The idea is simple: suppose you have a commonly used method that has two execution paths – one is very common and simple, and the second one takes longer to execute, has more steps…

12

Dissecting the new() constraint in C#: a perfect example of a leaky abstraction

Most likely you’ve heard about The Law of Leaky Abstractions coined by Joel Spolsky. Even if you never heard of it, you definitely faced it in your day-to-day job. The “law” is pretty simple: “All non-trivial abstractions, to some degree, are leaky”. And this is 100% true. But sometimes even not that complicated abstractions can…

31

Understanding different GC modes with Concurrency Visualizer

In this post I’m going to visualize what exactly happens during Garbage Collection (GC) and how different GC modes can significantly affect application performance. I assume that the reader is familiar with garbage collection basics. If this isn’t the case I encourage you to spend 15 minutes to fill this gap, for instance from the…

11

Dissecting the ActionBlock: a Short Story About a Nasty Deadlock

I think almost every project in the real world uses some form of producer-consumer queue. The idea behind this problem is very simple. Application needs to decouple consumers of some data from the logic that processes it. Consider, for instance, the thread pool from the CLR: application can schedule some work using ThreadPool.QueueUserWorkItem and the…

2

Dissecting the code: yet another programmer’s blog

Hi everyone. My name is Sergey Tepliakov; I’m Senior Software Engineer at TSE(*) team at Microsoft. At my day-to-day job I’m working on a next-gen build engine with tons of very useful capabilities. But don’t worry, I’m not going to dig into this topic. At least for now:) Before joining Microsoft 2 years ago, I’ve…

4