deno_std VS DOOM

For reference (for the issues you mentioned): 1. This issue was opened almost immediately to solve the weird .only function not working https://github.com/denoland/deno_std/issues/2979 2. That looks weird to me, will get back to you on this one since it should work I think 3. Generally polluting the global namespace isn't great, but because we're only polluting the namespace of a module (and we choose what parts to import), I personally find it quite freeing. I entirely understand how that might feel awkward. 4. you CAN specifying only writing to certain directories! --allow-write=/path/to/dir would allow that!

At least for the ones related to trees, it's just a renaming. Below is a link to the PR. When I initially implemented these trees, I chose the names BSTree and RBTree to keep the names short. I'm guessing the person that proposed renaming them did so to make it more obvious what they are.

https://github.com/denoland/deno_std/pull/2400

The standard library is separate from the runtime. It wouldn't break backward compatibility if you were to update. For example, if you were importing RBTree and upgraded Deno to the latest release, it would keep working just fine. You would only really need to switch to using RedBlackTree instead if there was a change made to it that you wanted.

I think the only time you would need to update your standard module imports to be able to use newer versions of the Deno runtime if the standard module were depending on runtime APIs that have a breaking change.

It is like Demo deprecating fs.exists().[1]

[1]https://github.com/denoland/deno_std/discussions/2102

This was fun to read through.

I would need to profile the code, but the startup time being bad for Deno seems like maybe a combination of the code in here being unoptimized:

https://github.com/denoland/deno_std/blob/0ce558fec1a1beeda3...

(Ex. Lots of temporaries)

And usage of the readFileSync+TextDecoder API instead of readTextFile (which is also a docs issue since it's suggests the first one). It seems the code loads the 100MB into memory, then converts to another 100MB of utf8, then parses with that inefficient csv decoder. The rust and go versions look to be doing stream/incremental processing instead.

But it there's some talk to reconsider it

Sorry to hear that. I want to provide expect API in deno_std in the future: https://github.com/denoland/deno_std/issues/1779

I just migrated the module to Deno and rewrote the test cases using the Deno test runner. Also contributed a bug fix to the test runner that I encountered during the migration. An npm version is still available and automatically generated from the Deno code via a small bash script (rewriting imports, adding an index.ts, etc.).

Much of Node.js is written in C, yet it's still called Node.js.

Deno has some JavaScript/TypeScript in it. On GitHub https://github.com/denoland/deno is 22.8% JavaScript and 13.2% TypeScript, and https://github.com/denoland/deno_std is 68.2% JavaScript and 31.6% TypeScript.

So to me it's misleading about the name, but not about what Deno is written in.

commercially exploit or use for any commercial purpose."

[1] https://github.com/id-Software/DOOM/commit/4eb368a960647c8cc...

The original Doom had third-party audio playback routines, so the source came with a rewritten sound server: https://github.com/id-Software/DOOM/tree/master/sndserv

    The bad news:  this code only compiles and runs on linux.  We couldn't

Here's a repo for you with no test coverage and no auto-generated DI. They using unsafe pointers all over the place, too!

https://github.com/id-Software/DOOM

Shall I prepare the postage for the letter in which you'll call John Carmack an MBA? Should we send another to Chris Sawyer? I heard he didn't even write a formal design doc for Roller Coaster Tycoon!

cURL is one of the most used C libs and is an example of good quality C code. If you follow the style used there, see e.g. https://github.com/curl/curl/blob/master/lib/dynhds.h (and associated dynhds.c) you will be good.

Looking at the source of some of the old game-engines from the era that have since been released as open-source can also be helpful, like https://github.com/id-Software/DOOM.

In both cases notice how simple and elegant a lot of the code is. There is already enough complexity inherent in the problem they are solving, and that is where the focus should be.

Any IDE with a working language server to make it easy to jump around and refactor should work fine. Limitations might be due to the C language itself?

Error handling on such a fixed platform does not need to be super-advanced. You should always be within the confines of the system so there shouldn't be much that can go wrong. If stuff goes wrong anyway just being able call a function Fatal("FooBar failed with code 34") when unexpected stuff happens and have it log somewhere to be able to dig around should be enough. You never need to be able to recover and retry.

Make sure to use https://clang.llvm.org/docs/AddressSanitizer.html or a similar tool when developing outside of the PSOne.

That said, consider statically allocating global buffers for most stuff and avoid using the heap for most stuff.

Good luck working within the confines of the PSOne! Many hackers have pulled the hair from their head on that platform ;)

Probably more easily than you'd think. DOOM is open source[1], and as GP alludes, is probably the most frequently ported game in existence, so its source code almost certainly appears multiple times in GPT-4's training set, likely alongside multiple annotated explanations.

[1] https://github.com/id-Software/DOOM

I'd define an arena as the pattern where the arena itself owns N objects. So you free the arena to free all objects.

My first job was at EA working on console games (PS2, GameCube, XBox, no OS or virtual memory on any of them), and while at the time I was too junior to touch the memory allocators themselves, we were definitely not malloc-ing and freeing all the time.

It was more like you load data for the level in one stage, which creates a ton of data structures, and then you enter a loop to draw every frame quickly. There were many global variables.

---

Wikipedia calls it a region, zone, arena, area, or memory context, and that seems about right:

https://en.wikipedia.org/wiki/Region-based_memory_management

It describes history from 1967 (before C was invented!) and has some good examples from Apache ("pools") and Postgres ("memory contexts").

I also just looked at these codebases:

https://github.com/mit-pdos/xv6-public (based on code from the 70's)

https://github.com/id-Software/DOOM (1997)

I looked at allocproc() in xv6, and gives you an object from a fixed global array. A lot of C code in the 80's and 90's was essentially "kernel code" in that it didn't have an OS underneath it. Embedded systems didn't run on full-fledges OSes.

DOOM tends to use a lot of what I would call "pools" -- arrays of objects of a fixed size, and that's basically what I remember from EA.

Though in g_game.c, there is definitely an arena of size 0x20000 called "demobuffer". It's used with a bump allocator.

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So I'd say

- malloc / free of individual objects was NEVER what C code looked like (aside from toy code in college)

- arena allocators were used, but global vars and pools are also very common.

- arenas are more or less wash for memory safety. they help you in some ways, but hurt you in others.

The reason C programmers don't malloc/free all the time is for speed, not memory safety. Arenas are still unsafe.

When you free an arena, you have no guarantee there's nothing that points to it anymore.

Also, something that shouldn't be underestimated is that arena allocators break tools like ASAN, which use the malloc() free() interface. This was underscored to me by writing a garbage collector -- the custom allocator "broke" ASAN, and that was actually a problem:

https://www.oilshell.org/blog/2023/01/garbage-collector.html

If you want memory safety in your C code, you should be using ASAN (dynamically instrumented allocators) and good test coverage. Arenas don't help -- they can actually hurt. An arena is a trivial idea -- the problem is more if that usage pattern actually matches your application, and apps evolve over time.

Doom