"New projects do use Java or C# rather than C/C++ though."

But not for speed reasons. Java is in no way faster than well written C/C++

X is not faster than well written Y, for all X and Y; that's not a particularly useful comparison though. I've seen a project pick Java over C/C++ because, based on their previous experience, the memory leaks typical of C/C++ codebases were a worse performance problem than any Java overhead.

Well written Java is sure to be slower than well written C/C++.

Happy? ;)

But yes, the point you make, is valid, it is much harder to write C/C++ well, because of the burden of memory management. So if you lack the time or skilled people, it might make sense to choose Java out of perfomance reasons.

Java might not be, but C# is another matter.

Specially after the Midori and Singularity projects, and how it affected the design of C# 7.x low level features and UWP AOT compiler (shared with Visual C++).

Also Unity is porting engine code from C++ to C# thanks to their new native code compiler for their C# subset, HPC#.

The discussion was about JITs vs AoT compiled native code. Unity is not using a JIT runtime for their new Burst compiler but using LLVM to do AoT native compilation and getting rid of garbage collection. If you get rid of JIT and garbage collection then yes, a subset of C# can be competitive in performance with C++ for some uses.

JIT vs AOT is an implementation detail, nothing to do with a programming language as such, unless we are speaking about dynamic languages, traditionally very hard to AOT.

In fact C# always supported AOT compilation, just that Microsoft never bothered to actually optimize the generated code, as NGEN usage scenario is fast startup with dynamic linking for desktop applications.

While on Midori, Singularity, Windows 8.x Store, and now .NET Native, C# is always AOT compiled to native code, using static linking in some cases.

As for GC, C# always offered a few ways to avoid allocations, it is a matter for developers to actually learn to use the tools at their disposal.

With C# 7.x language features and the new Span related classes, it is even easier to avoid triggering the GC in high performance paths.

For someone who doesn't develop for the MS stack but is still curious, what are these ways to avoid allocations and GC in performance-critical paths?

Nah, nobody in their right mind would use Java/C# over C/C++ for performance...

http://blog.metaobject.com/2015/10/jitterdammerung.html?m=1

That’s a great blog post!

> I agree with Ousterhout's critics who say that the split into scripting languages and systems languages is arbitrary, Objective-C for example combines that approach into a single language, though one that is very much a hybrid itself. The "Objective" part is very similar to a scripting language, despite the fact that it is compiled ahead of time, in both performance and ease/speed of development, the C part does the heavy lifting of a systems language. Alas, Apple has worked continuously and fairly successfully at destroying both of these aspects and turning the language into a bad caricature of Java. However, although the split is arbitrary, the competing and diverging requirements are real, see Erlang's split into a functional language in the small and an object-oriented language in the large.

I still strongly think Apple is taking the wrong approach with Swift by not building on the ObjC hybrid model more.

Your article is correct that Java/C# performance is unpredictable. But, per the OP, C/C++ performance is also unpredictable, because C/C++ doesn't reflect what a modern processor actually does; there are cases where e.g. removing a field from a datastructure makes your performance multiple orders of magnitude worse because some cache lines now alias.

> New projects do use Java or C# rather than C/C++ though.

Nobody is picking Java/C# over C/C++ for performance reasons.

It is not that Java or C# are able to beat C and C++ on micro-benchmarks, rather they are fast enough for most tasks that need to be implemented, while providing more productivity.

The few cases where raw performance down to the the byte level and ms matter are pretty niche.

I've seen a project pick Java over C/C++ because of the memory leaks they saw in the latter in practice. You can call that a correctness issue rather than a performance issue if you like, but the practical impact was the same as a performance problem.