JITWatch VS wg-allocators

You can kind of do the same as DISASSEMBLE in Clojure.

There are some helper projects like https://github.com/Bronsa/tools.decompiler, and on the OpenJDK JitWatch (https://github.com/AdoptOpenJDK/jitwatch), other JVMs have similar tools as well.

It isn't as straightforward as in Lisp, but it is nonetheless doable.

As you have encapsulated the asserts inside methods, these will be called at runtime with the arguments evaluated (for example, creating that lambda). When assertions are disabled, the C1/C2 may inline the empty method call eventually, but I don't know whether it drops the lambda instantiation as well. You can use JITWatch to see what gets inlined. The general notion though is to not worry too much. Lazy log messages are a common pattern.

You can use jitwatch for this. To see the actual assembly code generated you will also need to use a debug build of the jvm.

If you use Oracle's own IDE, it will support it out of the box, as it already did on Sun's days.

Then there are other ways depending on which JVM implementation is used.

On OpenJDK's case you can load runtime plugin to do it

https://github.com/AdoptOpenJDK/jitwatch

We use https://github.com/AdoptOpenJDK/jitwatch for this.

If you already know any JVM or .NET language, the first step would be to understand the full stack, you don't need C for that.

Many of us were doing systems programming with other languages before C went mainstream.

What you need to learn is computer architecture.

Getting back to JVM or .NET, you can get hold of JIT Watch, VS debug mode or play online in SharpLab.

Get to understand how some code gets translated into MSIL/JVM, and how those bytecodes end up being converted into machine code.

https://github.com/AdoptOpenJDK/jitwatch/wiki/Screenshots

https://sharplab.io/

Languages like F# and C# allow you to leave the high level comfort and also do most of the stuff you would be doing in C.

Or just pick D, which provides the same comfort and goes even further in low level capabilities.

Use them to write a toy compiler, userspace driver, talking to GPIO pins in a PI, manipulating B-Tree data stuctures directly from inodes, a TCP/IP userspace driver.

Not advocating not to learn Zig, do it still, the more languages one learns the better.

Only advocating what might be an easier transition path into learning about systems programming concepts.

You can enable a lot of debug information about how the compiler decides what to do with your code using feature flags like -XX:+UnlockDiagnosticVMOptions -XX:+PrintInlining. If you want to dive deeper into the world of the Hotspot JIT Compiler, have a look at JITWatch.

In what concerns HotSpot, one way would be JITWatch.

Tracking issue for Storages, and a TLDR on what it is

I must have gotten confused, since from your brief discussion with CAD97 it seemed like there was a way for the concepts to live separately and that Storage could complicate things in comparison. But if implementing Allocator in terms of Storage is basically equivalent and Storage is flexible enough that I could write one to pass memory out to unsafe code, that works just as well.

https://rust-lang.github.io/rfcs/1974-global-allocators.html was the original RFC.

My vague understanding is that there's a working group https://github.com/rust-lang/wg-allocators

The further I get from working on Rust day to day, the less I know about these things, so that's all I've got for you.

If you self-reference using pointers and guarantee the struct will never move, you don't even need unsafe. If you self-reference using offsets from the struct's base pointer, you need a splash of unsafe but your struct can be freely moved without invalidating its self-referential "pointers".

Per-struct allocators are a work in progress (see https://github.com/rust-lang/wg-allocators/issues/48).

Not sure what "non thread local addresses" means, but in my experience Rust is pretty good at sending data between threads (without moving it).

Besides that allocation is not really a problem for no_std. It's resolved by using alloc crate directly, so anything usable with custom allocators is supported. Example in dasp sources - https://github.com/RustAudio/dasp/blob/master/dasp_slice/src/boxed.rs#L14-L19 . Also worth looking at this issue to check what is usable already - https://github.com/rust-lang/wg-allocators/issues/7

But that's on track for rust as well: https://github.com/rust-lang/wg-allocators/issues/7

Here: https://github.com/rust-lang/rfcs/pull/1398. there is also a working group for this: https://github.com/rust-lang/wg-allocators.

It's unstable. wg-allocators contains discussions about design and a tracking issue for collections that need an allocator https://github.com/rust-lang/wg-allocators/issues/7