r/cprogramming

I have an experimental web framework I'm currently working on.

While going through the code to clean up styling before tagging a stable release, I've been debating this specific part in the HTTPS module:

https://github.com/c4punks/CWIST/blob/dev/src/net/http/https.c

Right now, this code just uses a dumb, massive ring buffer to absorb connection bursts, and I'm wondering if I should switch it to a lock-free queue.

There are three main things that make me hesitate:

* State can get pretty tangled and messy in a lock-free queue.

* We have a tiny team and I'm maintaining almost all of this alone. If something breaks with CAS (even if the odds are low, if I mess up the code during refactoring), the blast radius on the dev branch will just be too big.

* I also wonder how often real-world traffic actually warrants lock-free. Plenty of web frameworks handle traffic just fine without this level of extreme optimization.

Considering that I'm still a junior developer and lack experience, is it really worth swapping this out for a lock-free structure, and would it actually make a noticeable difference?

I was asked an endianness question in a recent Embedded C interview.

For example:

uint32_t n = 0x12345678;

I had previously learned the typical byte-swap approach and also i can do it for 16 bit

n = ((n & 0x000000FF) << 24) |
    ((n & 0x0000FF00) << 8)  |
    ((n & 0x00FF0000) >> 8)  |
    ((n & 0xFF000000) >> 24);

However, the interviewer asked me to convert the endian representation and store the result into a byte array using a pointer to the destination.

During the interview, my mind immediately went to the bit-manipulation code I had memorized, and I failed to do the simple program. How can I improve my thought process?

I have programmed in C before including on the job, but those experiences never really gets me ready for the wideness of interviews. I was wondering if there's a resource that exposes the things I take for granted in Python (within the standard library) and explains how it works in C.

edit: I just had my interview, thanks for the responses! I went over every link I got

I'm new to C. I have a small SDL2 project. At some point I needed to load and draw image sprites and found nice library stb_image.h. Probably best way here would be to just download the stb_image.h file and commit it to the repo, but I thought it would be a nice exercise towards learning how to manage dependencies. Since C doesn't seem to have anything like cargo, PyPi or npm, I started to look for best practices on how to do that.

So, this is what I came up with so far, with a Makefile:

• dependency file as a target, with commit pinned as separate var

STB_IMAGE_COMMIT := 013ac3beddff3dbffafd5177e7972067cd2b5083

vendor/stb/stb_image.h:
	curl -fsSL --create-dirs https://raw.githubusercontent.com/nothings/stb/$(STB_IMAGE_COMMIT)/stb_image.h -o $@

• making it prerequisite to the main build target:

build/%.o: src/%.c | build vendor/stb/stb_image.h
	$(CC) $(CFLAGS) -c $< -o $@

This seems simple, reproducible and efficient to me. But I'm not sure it would scale well and also - maybe there are better approaches out there?

I have been involved in low-level programming for a long time: I write operating systems and have created both a more user-friendly dialect of C and a programming language—designed for driver and firmware development—that can be learned in just a few hours. However, I am reaching out to you now because I cannot handle this task alone. Whether you know how to write low-level code, simply have an interest in the field, or possess a deep understanding of how such programs work, I invite you to join me in creating a programming language specifically designed for an operating system. Thank you for taking the time to read this message—the future is ours to shape.

I have been programming Arduino & ESP32 for a while now using C++, but have never engaged with any formal introduction material. With AI/LLM generated content exploding among both major publishers and self-published authors, I am a bit wary to start buying books willy-nilly.

Anyone here that can give solid recommendations on introduction materials on C++ for microcontrollers (preferably that that they themselves have used and found worthwhile)?

I got one recommendation for "Embedded C" by Michael J. Pont (2002), but it is fairly old.

I'm sorry in advance if this isn't the space for this question, but I can't find much information on the subject. In my project I have a parent who forks several children and at one point, it will send SIGTERM to his still-alive kids. The kids, who are either working or "stuck" on a msgop. Immediately after receiving the signal, they get to... doing other things, including calling other functions and releasing or reserving sempahores, accessing a shared memory, doing other stuff based on whether they can make these semops. After these operations, the kids exit.

While my project still works like this, as it's a relatively small project, I'd like to code as correctly as possible and I read that signal handlers should be very short, preferably just few lines of code (like changing the sigatomic_t volatile variable's value). While it's my understanding that I'm supposed to check said variable's value somewhere in the code (and if it's changed, do everything I'm doing in the handler), I don't understand where I'm supposed to check its value because signals can interrupt the kids at any point in time.

Any sort of help, examples, explanations are extremely appreciated; I thank you in advance. Or even just someone pointing me to where I can find more examples, that specifically mention signal handlers and how my functions are supposed to be called immediately, that's also great.

(I can only use System V IPCs and none of my processes access the internet, in case it's relevant in any way)