"C is a simple language. This is fact I agree with and appreciate. It is the reason for C's endurance. If someone posts a patch or submits a PR to a codebase written in C, it is easier to review than any other mainstream language. There is no spooky at a distance."
Today I realized #Go and #Rust both have panics instead of exceptions and both originate from the second half of the 2000s.
These facts are now mentioned in https://gato-lang.dev/
If you have experience with Go or Rust, I'm interested in your thoughts on the lack of exceptions in these languages. It looks to me like an attempt to simplify things that eventually backfired, as evidenced for example by https://www.crowdstrike.com/en-us/blog/dealing-with-out-of-memory-conditions-in-rust/
#C++23 introduced `std::expected<>` for that reason, but SL doesn't use it yet for anything.
I want to be your next #FediHire ! I've been a programmer since 1985 (as a child), I've been an IT professional since 1995 (pulling wires and swapping cards and configuring MS Windows). I graduated from University of Arkansas Fayetteville with a BS in CS in December of 2003. A full resume is available.
I currently require a 100% remote position. I cannot relocate from Cove, #Arkansas. I would prefer W-2 employment with a base salary of at least 130k USD/yr, plus some sort of retirement offering (401k or similar) and healthcare benefits (HDCP + HSA or similar).
I prefer something where I can be a high-performing individual contributor: reading, writing and improving source text the majority of my day, with some time spent knowledge-sharing with other developers -- learning and teaching. I'd like to work with #Haskell, #Purescript, or #Idris as the primary source language. I've previously delivered value in Haskell, #Javascript, #SQL, #Python, #Scala, #Java, #C, and #C++ among others. I can be productive in almost any language (no PHP, please; I promised myself never again).
🕹️ Developing a Retro-Roguelike Game for Multiple Platforms in C
｢ The journey began with TRSE, a development environment supporting a huge number of vintage computer systems. My plan was to develop a text-based roguelike that could run on various hardware by compiling code for each target ｣
I need some advise: Is there a good portable and free (really free, not GPL!) #implementation of #bcrypt in #C around?
There's #OpenBSD source I could use, but integrating that would probably be quite a hassle...
Background: I want to start creating a second credential checker for #swad using files. And it probably makes sense to support a sane subset of #Apache's #htpasswd format here. Looking at the docs:
https://httpd.apache.org/docs/current/misc/password_encryptions.html
... the "sane subset" seems to be just bcrypt. MAYBE also this apache-specific flavor of "iterated" MD5, although that sounds a bit fishy ...
Today, I implemented the #async / #await pattern (as known from #csharp and meanwhile quite some other languages) ...
... in good old #C! 😎
Well, at least sort of.
* It requires some standard library support, namely #POSIX user context switching with #getcontext and friends, which was deprecated in POSIX-1.2008. But it's still available on many systems, including #FreeBSD, #NetBSD, #Linux (with #glibc). It's NOT available e.g. on #OpenBSD, or Linux with some alternative libc.
* I can't do anything about the basic language syntax, so some boilerplate comes with using it.
* It has some overhead (room for extra stacks, even extra syscalls as getcontext unfortunately also always saves/restores the signal mask)
But then ... async/await in C! 🥳
Here are the docs:
https://zirias.github.io/poser/api/latest/class_p_s_c___async_task.html
I finally eliminated the need for a dedicated #thread controlling the pam helper #process in #swad. 🥳
The building block that was still missing from #poser was a way to await some async I/O task performed on the main thread from a worker thread. So I added a class to allow exactly that. The naive implementation just signals the main thread to carry out the requested task and then waits on a #semaphore for completion, which of course blocks the worker thread.
Turns out we can actually do better, reaching similar functionality like e.g. #async / #await in C#: Release the worker thread to do other jobs while waiting. The key to this is user context switching support like offered by #POSIX-1.2001 #getcontext and friends. Unfortunately it was deprecated in POSIX-1.2008 without an obvious replacement (the docs basically say "use threads", which doesn't work for my scenario), but still lots of systems provide it, e.g. #FreeBSD, #NetBSD, #Linux (with #glibc) ...
The posercore lib now offers both implementations, prefering to use user context switching if available. It comes at a price: Every thread job now needs its private stack space (I allocated 64kiB there for now), and of course the switching takes some time as well, but that's very likely better than leaving a task idle waiting. And there's a restriction, resuming must still happen on the same thread that called the "await", so if this thread is currently busy, we have to wait a little bit longer. I still think it's a very nice solution. 😎
In any case, the code for the PAM credential checker module looks much cleaner now (the await "magic" happens on line 174):
https://github.com/Zirias/swad/blob/57eefe93cdad0df55ebede4bd877d22e7be1a7f8/src/bin/swad/cred/pamchecker.c
Found an issue and fixed it. Turns out destroying my #Process instance when the child exited was wrong, there could still be unread data in the #pipe. But then, only waiting for #EOF on the pipe was equally wrong ...
Now the code does the only reliable thing:
* When the child terminated, close the pipe for stdin immediately if one was present
* Only destroy the process instance once the child terminated AND the pipes for #stdout and #stderr (IF they were present) found EOF.
Committed now:
https://github.com/Zirias/poser/commit/18051d9da0ba7e4caf2882828e5706e35d419f94
And here are the docs:
https://zirias.github.io/poser/api/latest/class_p_s_c___process.html
My testing code also had to change a bit and now makes for a completely pointless and cute wrapper around /bin/ls 🙈 😂
On a #coding mission to improve my #poser lib 😎.
In the current implementation of #swad, I don't really like that I need an extra thread, just to control a child #process. A first piece to add to poser is generic "child process support", which I'm testing right now. I realized I could reuse my #Connection class, which was built for #sockets, but works just as well with #pipes 🙃
TODO now is mostly testing. See screenshots for some mimimal testing code and its output ... would you like this kind of interface? 🤔
About the #random thingie ... I need random data in #swad to generate unpredictable #session IDs.
I previously had an implementation trying the #Linux-originating #getrandom if available, with a fallback to a stupid internal #xorshift#PRNG, which could be disabled because it's obviously NOT cryptographically secure, and WAS disabled for the generation of session IDs.
Then I learned #arc4random is available on many systems nowadays (#FreeBSD, #NetBSD, even Linux with a recent-enough glibc), so I decided to add a compile check for it and replace the whole mess with nothing but an arc4random call IF it is available.
arc4random originates from #OpenBSD and provides the only sane way to get cryptographically secure random data. It automatically and transparently (re-)seeds from OS entropy sources, but uses an internal CSPRNG most of the time (nowadays typically #ChaCha20, so it's a misnomer, but hey ...). It never fails, it never blocks. It just works. Awesome.
I revisited that, AGAIN. Getting #random data in #poser now has yet another fallback, in case we don't have #arc4random and we also don't have #getrandom: read from /dev/random and/or /dev/urandom, "old style" 🙈. Still better to try this before resorting to a simple little #xorshift.
In the best case — arc4random found — this is still all the code of PSC_Random_bytes() 😆:
arc4random_buf(buf, count);
return count;
https://zirias.github.io/poser/api/latest/class_p_s_c___random.html
Nice, #threadpool overhaul done. Removed two locks ( #mutex) and two condition variables, replaced by a single lock and a single #semaphore. 😎 Simplifies the overall structure a lot, and it's probably safe to assume slightly better performance in contended situations as well. And so far, #valgrind's helgrind tool doesn't find anything to complain about. 🙃
Looking at the screenshot, I should probably make #swad default to two threads per CPU and expose the setting in the configuration file. When some thread jobs are expected to block, having more threads than CPUs is probably better.
https://github.com/Zirias/poser/commit/995c27352615a65723fbd1833b2d36781cbeff4d
More #poser improvements:
* Use arc4random() if available, avoids excessive syscalls just to get high-quality random data
* Add a "resolver" to do #reverse#DNS lookups in a batch, remove the reverse lookup stuff from the connection which was often useless anyways, when a short-lived connection was deleted before resolving could finish 🙈
As a result, #swad can now reliably log requests with reverse lookups enabled 🥳
Still working on #swad, and currently very busy with improving quality, most of the actual work done inside my #poser library.
After finally supporting #kqueue and #epoll, I now integrated #xxhash to completely replace my previous stupid and naive hashing. I also added a more involved #dictionary class as an alternative to the already existing #hashtable. While the hashtable's size must be pre-configured and collissions are only ever resolved by storing linked lists, the new dictionary dynamically nests multiple hashtables (using different bits of a single hash value). I hope to achieve acceptable scaling while maintaining also acceptable memory overhead that way ...
#swad already uses both container classes as appropriate.
Next I'll probably revisit poser's #threadpool. I think I could replace #pthread condition variables by "simple" #semaphores, which should also reduce overhead ...
I am in urgent job search mode, so I'm gonna throw this out here and see if anything comes of it.
I am a #Canadian, fluent in both #English and #French. I have experience with several programming languages. My strongest proficiency is with #Haskell and #C. I also have a reasonable grasp of #HTML, #JavaScript, #SQL, #Python, #Lua, #Linux system administration, #bash scripting, #Perl, #AWK, some #Lisp (common, scheme, and emacs), and probably several others I've forgotten to mention.
I am not necessarily looking for something in tech. I just need something stable. I have done everything from software development, to customer support, to factory work, though my current circumstances make in-person work more difficult than remote work. I have been regarded as a hard worker in every job I have ever held.
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