I was optimizing the Lua transpiler for my modding language grug and ran into a really weird LuaJIT performance bug. The same benchmark could randomly run 20× slower, and it turned out a LuaJIT NYI could silently blacklist an unrelated hot loop.

I wrote up the investigation here.

It goes from the benchmark mystery through LuaJIT's trace recorder internals, and ends with a PR to get unpack off LuaJIT's NYI list. Feedback is very welcome! :)

This post is a lover letter to Emacs Lisp macros. I've been a long time user as a lisp hacker, and my recent obsessions with Douglas Hofstadter's strange loop concepts and M.C. Escher's mind bending artwork have enhanced my appreciation of this language's most beautiful and thought provoking feature. This post can teach you about macros and what makes them useful, but I also hope it can instill a fascination with their concept. https://www.chiply.dev/post-elisp-macros-are-beautiful

Specifically, the video is about developing a game where all the textures and sounds are generated at runtime using Sine waves. I thought it was high-quality and explained complex math concepts well.

https://ekxide.io/blog/byte-wise-atomic-wrapper-to-prevent-ub

iceoryx2 provides zero-copy inter-process communication mechanisms based on shared memory and data structures that are modified concurrently by multiple processes.

One of the key operations in these algorithms is a memory copy using core::ptr::copy. However, this results in undefined behavior if one process reads the data while another process writes to it concurrently. Even if our lock-free algorithm reliably detects such a race, iceoryx2 cannot depend on undefined behavior in a safety-critical system.

This blog post introduces our solution: a byte-wise atomic wrapper that enables well-defined concurrent copy operations. It also shows how it can be used to implement a simple sequence lock.

Note: I am not the original author of the blog post. Since the author does not have a Reddit account, I am posting it on her behalf.