Better Dev Link

The Apollo “8-Ball” FDAI (Flight Director/Attitude Indicator) was a crucial instrument in Apollo spacecraft, used to display the vehicle’s orientation. The article details its complex internal workings, which include a multi-axis rotating ball mechanism driven by three motors and a servo loop. The specific unit examined was later modified for use in a Space Shuttle simulator, with changes made to its components and markings.

There are some latency numbers that every programmer should know, according to Jeff Dean, and one of them is branch misprediction, which costs around 5ns in 2012, and the latency remains roughly the same as the time of writing this post. So what is branch prediction, what happens when it’s mispredicted, and why is it costly?

Making programs slower can be useful to find race conditions, to simulate speedups, and to assess how accurate profilers are. To detect race conditions, we may want to use an approach similar to fuzzing. Instead of exploring a program’s implementation by varying its input, we can explore different instruction interleavings, thread or event schedules, by slowing down program parts to change timings. This approach allows us to identify concurrency bugs and is used by CHESS, WAFFLE, and NACD.

UIDv7 is a highly important and long-awaited feature that addresses a major pain point for developers who use UUIDs as primary keys in databases. Unlike older versions like UUIDv4, which are randomly generated and lead to poor performance and index bloat in B-tree indexes, UUIDv7 incorporates a Unix Epoch timestamp. This makes it time-ordered, ensuring that new UUIDs are inserted sequentially, which significantly improves performance for write-heavy workloads. The article emphasizes that this quiet but impactful addition “brings the best of both worlds” by providing global uniqueness while also being sortable and performance-friendly.

I always like syntax highling algorithm. It’s something we take for granted and didn’t ask how it can be done. Andy walked us through how he do it for his own shell language.

The webpage describes a new method for GPU text rendering that uses vector data of glyphs instead of pre-baked textures, addressing issues like poor quality with certain fonts and large texture sizes. The approach involves loading raw Bézier curves, sending them to the GPU, and rasterizing them at runtime with a temporal accumulation technique for high-quality anti-aliasing. This method also allows for customized subpixel anti-aliasing to eliminate color fringing on different monitor layouts.

Collaboratively editing strings of text is a common desire in peer-to-peer applications. For example, a note-taking app might represent each document as a single collaboratively-edited string of text.

The algorithm presented here is one way to do this. It comes from a family of algorithms called CRDTs, which I will not describe here. It’s similar to the approaches taken by popular collaborative text editing libraries such as Yjs and Automerge. Other articles have already been written about these similar approaches (see the references section below), but this article also has a nice interactive visualization of what goes on under the hood.

Speed kills rigor. In startups, the pressure to ship fast pushes teams to report anything that looks like an improvement. That’s how p-hacking happens. This piece breaks down three common cases—and how to avoid them

explains how Compiler Explorer works, a popular online tool for compiling code and viewing assembly output. The site handles millions of compilations annually, using Google’s nsjail tool for security to isolate compilation processes. To manage a massive 4 terabyte collection of over 4,700 compiler versions and reduce latency, it uses squashfs images mounted over NFS. The article concludes by discussing the site’s future plans, including the addition of an AI explanation tool and user accounts.

Have you ever scratch your head and see why your program seems hang? with very low CPU utilization? When you do strace it just show a bunch of FUTEX. In this short article we just learn some useful options and flags of strace to debug these easiser

the short of it is: they’re cool for appending notes from automated systems (like ticket or build systems) but not really for having interactive conversations with other developers (at least not yet)