Arenas and the almighty concatenation operator

This article was discussed on Hacker News. Over the past month I’ve been exploring the rapidly evolving world of Large Language Models (LLM). It’s now accessible enough to run a LLM on a Raspberry Pi smarter than the original ChatGPT (November 2022). A modest desktop or laptop supports even smarter AI. It’s also private, offline, unlimited, and...

Windows paths have been WTF-16-encoded for decades, but module names in the import tables of Portable Executable are octets. If a name contains values beyond ASCII — technically out of spec — then the dynamic linker must somehow decode those octets into Unicode in order to construct a lookup path. There are multiple ways this could be done, and...

I’m 18 years late, but Slim Reader/Writer Locks have a fantastic interface: pointer-sized (“slim”), zero-initialized, and non-allocating. Lacking cleanup, they compose naturally with arena allocation. Sounds like a futex? That’s because they’re built on futexes introduced at the same time. They’re also complemented by condition variables with the...

Suppose you’re working in C using one of the major toolchains — that is, it’s mainly a C++ implementation — and you need regular expressions. You could integrate a library, but there’s a regex implementation in the C++ standard library included with your compiler, just within reach. As a resourceful engineer, using an asset already in hand seems...

I recently came across a take-home C programming test which had more depth and complexity than I suspect the interviewer intended. While considering it, I also came up with a novel, or at least unconventional, solution. The problem is to deep copy a linked list where each node references a random list element in addition to usual linkage —...