The biggest problem with FFI in Go (gc, at least) isn't in the FFI operation itself, rather FFI functions that block for a long time mess with the scheduler.
It seems C# suffers the same problem as real-world benchmarks often show it to be slower than Go when performing FFI, even if it should be theoretically faster.
As usual, performance can be hard to predict. Benchmarking the actual code you intend to use is the only way to ensure that what you think is true actually is. If you aren't measuring, you aren't engineering.
Do you have any example of code that can demonstrate how it is possible to meaningfully slow down .NET and its threadpool and GC when performing FFI where Go does not suffer to a significantly greater extent?
(if you fashion a Go example - that'll be enough and I'll make a C# one)
.NET's threadpool is specifically made with the consideration of worker threads being potentially blocked in mind, and has two mechanisms to counteract it - hill-climbing algorithm that grows and shrinks the active number of threads to minimize task wait time in queues, and another mechanism to actively detect blocked threads (like system sleep or blocked by synchronous network read) and inject additional workers without waiting for hill-climbing to kick in. It is a very resilient design. Go's and Tokio threadpool are comparatively lower effort - both are work-stealing designs but neither has the active scaling mechanism .NET has already had since .NET Framework days.
GC implementation at the same time is pinning-aware and can shuffle around memory in such a way to allow other objects to participate in collection or promotion to older generations while keeping the pinned memory where it is. There have been years of work towards improving this, and there is also an additional pinned memory heap for long-lived pinned allocations on the rare occasion where just performing malloc is not appropriate.
I doubt there is any other high-level language or platform that can compete on FFI with .NET, something that has been considered as a part of its design since the very first version. If you want better experience your main upgrade options are literally C, C++, Zig, Rust, and honorable mention Swift (it is mostly a side-grade, with the heavy lifting done by LLVM).
No better than your own code. Why not put it to the test? In the end you will either know that you made the right choice, or have the better solution ready to swap in. You can't lose.
The key takeaway from the previous comment isn't some pointless C# vs Go comparison, it is that performance can be hard to predict. Someone else's code isn't yours. It won't tell you anything about yours. Measure and find out!
What, exactly, is interesting about arbitrary benchmarks? It might just be the C# code is slower because the developer accidentally introduced different, less performant, logic. It doesn't tell you anything. Only your own code can tell you something. I am not sure how to state this more clearly.
What would actually be interesting is to see you gain those important nanoseconds of performance that is so critical to your business. We want to see you succeed (even if you don't seem the want the same for yourself?).
> It might just be the C# code is slower because the developer accidentally introduced different, less performant, logic
That is why the user is asking for specific code. So they can audit whether this is a case when someone claims Go FFI is fine.
As an outsider, all I see are two people saying "no it's not slow," just about different languages. But until I have a production app in either I'll never know.
> So they can audit whether this is a case when someone claims Go FFI is fine.
Of course nobody would claim such a thing. The cost is real. Whether or not Go is fine will depend entirely on what kind of problem environment you are dealing with and what your own code actually looks like. Someone else's code will never tell you this. There is no shortcut here other than to measure your own code.
> As an outsider, all I see are two people saying "no it's not slow," just about different languages.
It is slow, relatively speaking. But does that matter in your particular situation? Random internet benchmarks show that Python is always slower, way slower, yet people find all kinds of productive uses for Python – even in domains where computational performance is very important! And if it does matter for what you're doing, are you sure you actually picked the fastest option? Measure and find out.
It is good to have rough estimates, but all of these languages are operating within the same approximate timescale here. It's not like Go, C#, or any other language is taking minutes to perform FFI. When you really do need to shave those nanoseconds off, guessing isn't going to get you there. Measure!
I'm in agreement, but it's even simpler than you're making it.
If Go is slow in a certain context, I would want to know what that context is. If there's a certain task that takes a few more ms in goroutines due to some implementation detail, I would know not to use Go if that task needed to be 100,000 times. Perhaps I need to rethink the task itself, or maybe that's not possible for an organizational reason.
It wouldn't be a "random internet benchmark" unless I didn't understand the context. What's random is saying this
>It seems C# suffers the same problem as real-world benchmarks often show it to be slower than Go when performing FFI, even if it should be theoretically faster
> If Go is slow in a certain context, I would want to know what that context is.
You'll know as soon as you measure it. Not exactly rocket science, just plain old engineering. Measuring is what engineers do. You wouldn't build a bridge without first measuring the properties of the materials, and you wouldn't build a program without measuring the properties of its 'materials'.
You make a good point that it is strange we don't get better datasheets from 'material manufacturers' about the base measurements. That wouldn't fly in any other engineering discipline, but I guess that's the nature of software still being young. As unfortunate as that may be, you can't fight the state of affairs, you're just going to have to roll up your sleeves. Such is life.
> How is this better than asking for code examples?
That's better for YOU if you are trying to get answers, but for me the reader, you made up something about C# in the hopes of being corrected, and then lectured people asking for receipts.
> That's better for YOU if you are trying to get answers
Indeed. No sense in breaking the law.
> but for me the reader
I bet they wrote a song about you – or at least, as the song goes, so you think.
> you made up something about C# in the hopes of being corrected
It wasn't made up. The FFI benchmarks I looked at truly did show that. I did not verify exactly what was the cause for the slowness, though – and I clearly maintained the doubt in the original comment in recognition of that. Speculation isn't quite the same as what you are postulating.
Nice execution of Cunningham's law, by the way. Now you're getting it. Welcome to the internet! You're going to like it here.
It seems C# suffers the same problem as real-world benchmarks often show it to be slower than Go when performing FFI, even if it should be theoretically faster.
As usual, performance can be hard to predict. Benchmarking the actual code you intend to use is the only way to ensure that what you think is true actually is. If you aren't measuring, you aren't engineering.