mps VS lone

I have a library which has an extremely slow free, around 2m for large files, because of unnaturally scattered allocation patterns, but this old conservative GC didn't help at all. It was about 40% slower with libgc. mimalloc was a bit better. Best would be a properly fast GC, like mps https://github.com/Ravenbrook/mps, but this would be too much work.

The first thing you should look at is MPS (see https://github.com/Ravenbrook/mps and https://www.ravenbrook.com/project/mps/). It's open source, professionally maintained and very powerful, and it was used e.g. in Dylan and LispWorks.

I wonder how the MMTK compares to the venerable Ravenbrook MPS https://www.ravenbrook.com/project/mps/ which originated in Harlequin’s programming language implementations, particularly Dylan.

I am trying to implement garbage collection for my language because I want memory management for arrays/lists and strings. I am looking through LLVM's garbage collection page but the documentation isn't great. Are there any other resources that offer more concrete steps to implement garbage collection? Would it be wise to circumvent LLVM all together for garbage collection and only use something like the Memory Pool System? Thanks!

This post seems related to the authors of MPS (1) that seems to be a general garbage-collector to use with various languages.

Many GC'd languages really didn't bother with stack-allocating variable-size entities, and regardless of if they did then _precicely_ scanning the stack would be complicated without compiler help.

If the compiler doesn't leave any info to the GC, then it can't know if it's scanning a pointer or a float and if your GC strategy relies on compacting memory (ie moving objects) then trying to guess between a float or a pointer can become fatal.

(1) https://github.com/Ravenbrook/mps

I made something somewhat close to that: a freestanding lisp. It targets the Linux kernel directly. No libc.

https://github.com/lone-lang/lone

> register scanning isn't portable

Certainly not but it wasn't particularly hard to implement either. I just wrote some inline assembly for every architecture. Here's my programming language's x86_64 and aarch64 implementations:

https://github.com/lone-lang/lone/blob/master/architecture/x...

https://github.com/lone-lang/lone/blob/master/architecture/a...

Not too long ago, a project of mine was shared here on HN.

https://news.ycombinator.com/item?id=38126052

In that thread I wrote:

> I have this vision in my mind: embedding lone modules into sections of the lone ELF and shipping it out. Zero dependencies, self-contained.

I've been working on that since that day. Proud to say I've gotten it to work and thought I'd make it the subject of my first Show HN. Some free software projects gained features along the way too.

The link is to an article with a proper demonstration, technical details and what happened in the past few weeks.

The complete repository itself can be found here:

https://github.com/lone-lang/lone

I've completely reorganized it since the last thread. Would be very happy if you guys tried it out.

To test my programming language. It's a freestanding lisp interpreter that doesn't link to libc. I wrote the code that handles the environment variables and in order to test it I needed full control over the program's inputs including its environment. The env utility provides this control by emptying the environment and setting only the variables I specify, solving 90% of the problem. Only thing I still can't control is argv[0]. With this new feature upstreamed, my test suite will be complete.

Here's the code if you'd like to take a look:

https://github.com/lone-lang/lone#testing

https://github.com/lone-lang/lone/blob/master/scripts/test.b...

> only to be confronted with the notorious 'incompatible glibc version error'. It's super annoying.

I started making my own freestanding Linux Lisp because of this exact issue. It's nowhere near as performant as something like SBCL but it's small and once compiled has no dependencies and will literally run on any Linux.

https://github.com/lone-lang/lone

I'm taking a break from this project but I plan to add a feature where I can put a Lisp script into the ELF itself so I can just copy it with the scripts included.

The kernel just puts the data contiguously on the stack. Obtaining pointers to them can seem somewhat magical if you're writing a nolibc program but I wouldn't call it horrible.

I implemented it for my programming language with some rather simple assembly code:

https://github.com/lone-lang/lone/blob/master/arch/x86_64.c#...

https://github.com/lone-lang/lone/blob/master/arch/aarch64.c...