dalvrosa

187 karma · joined February 25, 2026

Software Engineer @ Susquehanna | Algorithmic Trading | Low-Latency Systems | High-Performance Computing

https://david.alvarezrosa.com

submissions comments

dalvrosa··on OpenAI’s Navier-Stokes release included a Lean 4 formal proof

Yep

dalvrosa··on [dead]

Love it

dalvrosa··on Optimizing a Spin-Lock

Thanks!

dalvrosa··on Optimizing a Spin-Lock

A spin-lock is a lock that never sleeps. Instead of yielding to the scheduler, the thread stays on the CPU and spins. No syscalls. No context switches. In this post, we’ll build a version, step by step, that is 5.7x faster while drawing 5.4x less energy.

dalvrosa··on Move in C++ without a std:move

Not sure what you mean, but std::move is one of the greatest tools in C++

dalvrosa··on Self-Hosting on the Dark Web

It is the FBI lol

dalvrosa··on Self-Hosting on the Dark Web

Thanks! Glad that you liked it

dalvrosa··on First Steps on a New Server

Over the last decade I’ve been playing with dozens of servers from multiple providers. These are the steps I’ve been perfecting to get up to speed fast and feel right at home on a new machine. Wrote it down here mostly as a personal reference, but hopefully useful to someone else too.

dalvrosa··on Fundamental Theorem of Calculus

Glad that you like it :)

dalvrosa··on Fundamental Theorem of Calculus

Very. Very nice

dalvrosa··on Fundamental Theorem of Calculus

Thanks for bringing some intuition!

dalvrosa··on Fundamental Theorem of Calculus

Fair, sorry about that

dalvrosa··on Fundamental Theorem of Calculus

Great example

dalvrosa··on Fundamental Theorem of Calculus

Here is used in the Lebesgue measure theory sense

dalvrosa··on Fundamental Theorem of Calculus

Already replied :)

The source code of the website is open if you wanna check it out!

dalvrosa··on Fundamental Theorem of Calculus

There is some geometric intuition in wikipedia page for this theorem you may like :)

dalvrosa··on Moving from GitHub to Codeberg, for lazy people

Fair

dalvrosa··on A Faster Alternative to Jq

Fair, but agentic tooling can benefit quite a lot from this

Opencode, ClaudeCode, etc, feel slow. Whatever make them faster is a win :)

dalvrosa··on Optimizing a lock-free ring buffer

Lol. Funny story :)

dalvrosa··on Optimizing a lock-free ring buffer

Thanks for the explanation :)

dalvrosa··on Optimizing a lock-free ring buffer

Thanks!

dalvrosa··on Optimizing a lock-free ring buffer

I'm not sure about the single-core scenario, but would love to learn if someone else wants to add something

In reality multiple threads for single core doesn't make much sense right?

dalvrosa··on Optimizing a lock-free ring buffer

Thanks. Do you happen to know why hyperthreading should be disabled?

In prod most trading companies do disable it, not sure about generic benchmarks best practices

dalvrosa··on Optimizing a lock-free ring buffer

Nice one!

dalvrosa··on Moving from GitHub to Codeberg, for lazy people

Codeberg vs selfhosted Gitlab. What do you think?

dalvrosa··on Optimizing a lock-free ring buffer

Agreed. For benchmarking I used this <https://github.com/david-alvarez-rosa/CppPlayground/blob/mai...> which relies on GoogleBenchmark and pins producer/consumer threads to dedicated CPU cores

What else could be improved? Would like to learn :)

Maybe using huge pages?

dalvrosa··on Optimizing a lock-free ring buffer

Exactly, that's right

dalvrosa··on Optimizing a lock-free ring buffer

Thanks! That's not ensured, optimizations are only valid due to the constraints

- One single producer thread

- One single consumer thread

- Fixed buffer capacity

So to answer

> Are they ensuring two threads can't push to the same slot nor pop the same value from the ring?

No need for this usecase :)

dalvrosa··on Optimizing a lock-free ring buffer

Thanks for the feedback <3

dalvrosa··on Optimizing a lock-free ring buffer

100% agree +1

← PreviousPage 2 of 3Next →