code and bitters

I've been experimenting with Rust lately, and have just started following Jon Gjengset's videos. In his latest livestream, Jon started a port of the Java ConcurrentHashMap to Rust. I highly recommend them; it's fun to see how someone with a lot of Rust experience approaches problems.

One of the things that grabbed my attention was his use of crossbeam::epoch. It's a library that helps you write certain kinds of lock-free concurrent data structures, using an "epoch counter" that allows you to disconnect objects from your main data structure and they will be freed later-- without using any per-object atomic reference counters or other major GC overhead.

How… interesting.

An open source program (ogg123) has been crashing repeatedly on my new laptop. The source code hasn’t changed in years. The stacktrace always points to __lll_unlock_elision() in glibc, which seems kind of scary. Searches on the web all seem to point back to problems with Haswell CPUs that have broken TSX instructions, and are running out-of-date microcode.

In a busy multithreaded program that opens and closes files a lot, it's surprisingly easy for a minor C mistake to cause data corruption.

The Brigadier is a very simple way to make hot chocolate interesting.

I really hate unix signals. So I agree wholeheartedly with the sentiment here:

signalfd is useless