Hey r/programming!

I wrote a comprehensive article on constructing a mutex from scratch.

It covers:
- Data races: what happens at the register level, and how parallel access can go wrong
- Atomics & Memory Ordering: why atomics work and what each memory ordering does (Aq/Rel/AqRel/SeqCst)
- Spin lock & Guards: Building a simple mutual exclusion lock via an AtomicBool, and providing safe access to the protected data
- And finally, Mutexes: A more complex mutual exclusion primitive that can achieve better performance via thread::park/::unpark

The article benchmarks and compares the performance of both a spinlock and Mutex to understand when to use which.

Have you ever noticed a massive performance boost from switching from one synchronization primitive to another?
Feedback on the article is also appreciated!

A brief argument framing software creation, and specifically the details of the code, as an act of art

If you're experiencing actions stuck in a queued state, it's not you:

Update - We’re are currently investigating degraded availability affecting GitHub Actions, GitHub Pages and Webhooks.

Customers may experience delays in workflow processing, site builds and webhook delivery.

Oct 19, 2026 - 15:56 UTC

Update - Webhooks is experiencing degraded performance. We are continuing to investigate.
Oct 19, 2026 - 15:50 UTC

Investigating - We are investigating reports of degraded performance for Actions and Pages
Oct 19, 2026 - 15:49 UTC

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Why is unemployment rate of recent CS and CE grads at 7 and 7.8% compared to the natural rate of unemployment of 4.2%. The whole economy is still going fine but recent graduates of cs and ce have an outsized affect.

Overall unemployment rate of recent graduates is also 5.7%

Two weeks ago, I posted about how ClickHouse outcompressed Parquet on my IoT dataset.

But just days ago, pcodec was merged into ClickHouse, and it significantly improves on compression ratio while also trading blows on decompression speed with the previous schema.

It's a rather niche and sophisticated codec though, at least compared to the ones we had before in ClickHouse, so I thought I'd make a post where I try to explain the key conceptual ideas behind it. Enjoy!

Turns out, quite tough!