MINTIA (not vibecoded)

[green pelican]

anything to make the gdp go up i guess

[mortal thunder]

this is why it baffles me that trump is turning america in favor of russia

[coarse current]

is he?

[mortal thunder]

well

yeah havent you seen

how hostile he is to ukraine

[coarse current]

he was, then he wasn't

[green pelican]

tbf trump is hostile to just about everyone

he obviously doesnt like zelensky though

[mortal thunder]

does "just about everyone" include putin

i dont see it

[green pelican]

theres more tarrifs and sanctions planned on russia so yeah i think it does

[coarse current]

Things are so confusing and changing so quickly I stopped reading the news lately

[mortal thunder]

true

the best thing ive done this month for my health tbh was starting to walk daily

but then also logging off of X with no intention of logging back in

was about time

should've been done a long time ago but yeah

(im reaching 3 weeks)

[white valley]

i dont use X

or instagram

or tiktok

[green pelican]

isnt that because they're all banned in turkey

[white valley]

i just check r/turkey a few times a week to see whats up

[white valley]

no?

[green pelican]

i could've sworn they banned instagram a while back

[white valley]

oh yeah

but that was protested and reverted pretty quickly

we do have discord banned

[green pelican]

lmao why discord of all things

i get stuff like signal and telegram because end to end encryption and feds hate that

[coarse current]

because of these conversations

[white valley]

a guy beheaded his gf and threw her head from on top of a castle

[green pelican]

but discord will bend over backwards to appease local gov

[white valley]

they were like

hmm this guy is an "incel"

and discord has "incel" groups

[green pelican]

most mentally stable discord user

[coarse current]

discord is a us company

[white valley]

so they were like "ok clearly discord is the issue" and banned it

[white valley]

im trying to explain why it got banned

dumbo

[coarse current]

russia has banned youtube

[green pelican]

i was being sarcastic

[coarse current]

and discord as well

[white valley]

i wasnt

[green pelican]

that is somehow not as dumb a reason to ban it as i had expected tbh

[white valley]

yeah it's not too bad of a reason

but it still destroyed a bunch of programming communities

and jobs too

[green pelican]

usually its like somebody on this platform called my mom gay and now i want it banned

[white valley]

for people who did contract work over discord

[white valley]

the closest we have to that is the wikipedia / pastebin bans

[coarse current]

just use vpn?

[white valley]

tho wikipedia is no longer banned

[coarse current]

banning something that programmers use is the dumbest thing ever

[white valley]

not everyone is going to bother installing one

like me

i just use zapret

[green pelican]

makes it pretty hard to file your taxes if you're getting work over a banned platform

kinda screwed if you get audited

[coarse current]

russian technology lol

[white valley]

russians / eastern europeans are good as fuck at 2 things

1. circumventing censorship

2. piracy

[green pelican]

you forgot drink driving

[coarse current]

do you know how it works?

it's kinda funny

[white valley]

mostly

they do weird shit with the packets so that the isp cant detect the website names

like putting whitespace

[coarse current]

like it fools DPIs and you connect to servers as normal, directly

[white valley]

or delaying the packets in weird ways / sending them in chunks

[white valley]

still have to use a diff DNS tho

[coarse current]

ofc

[white valley]

anyways

im glad i installed zapret

since it unblocked literally every single banned werbsite

which includes PASTEBIN

you have no idea how much i suffered cuz of no pastebin access

i would have a heart attack every time someone was like "oh yeah check out my code!!" and it was a pastebin link

[green pelican]

my method of choice has been a free tier ec2 instance running openvpn

its pretty robust since most isps dont want to ban aws ip ranges

thankfully havent needed it too much in canada but when i visit england its useful

[white valley]

what did england block

[green pelican]

its the other way around, alot of places have ip banned england

theres some new rules around moderating online content that makes it basically impossible to run a website there if you're not a megacorp

[white valley]

niice

[coarse current]

except russia, and they're also banning openvpn by its signature

[green pelican]

also england ocassionally goes on a power trip and bans an ip range that actually covers more than they wanted to ban

[coarse current]

they've banned cloudflare recently

after they've enable ech

[green pelican]

good jobs guys you banned russia today but you also banned every single other ip address in eastern europe for 2 days

[white valley]

also

turkey recently banned

alcohol brand websites

i didnt even know those existed lmao

we have so much banned internet shit it's incredible

im surprised reddit isnt banned yet

[green pelican]

did you know 99% of authoritarian states stop censoring the internet right before civil unrest stops

[white valley]

i knew turkey does it

cuz i fuckin live here

usually when a terrorist attack / huge protests like what's happening rn happen

they bandwidth throttle all the big social media websites

[twilit smelt]

Just lie lol

Ahhh yeah I got caught stealing like 500 twinkies from the grocery store delivery truck

I was gonna resell them at the college campus and undercut the vending machine prices

That's what I'd say

[mortal thunder]

🗣️

[white valley]

oddly specific

[twilit smelt]

tomorrow ill start designing the io system in earnest hopefully

the packet stuff i wrote is already obsolete

[white valley]

why not design everything before implementing a single part of it

[twilit smelt]

?

i implemented io packets thinking id do the io system the same way i did in old mintia

after that i decided to read up on plug n play and stuff and ended up changing my ideas for how i wanted to do it big time

[white valley]

i see

[twilit smelt]

Basically I'm no longer satisfied with doing stuff like 80s-y ways

I want to design stuff really flexibly and extensibly and not make goofy 1989 assumptions like "the set of hardware won't change substantially after boot"

[white valley]

what happened to 89 larping

are you just gonna ignore that aspect now

[twilit smelt]

Still doing that aesthetically but what I've written so far is already definitely anachronistic for 1989

Turnstiles, fancy scheduler, pervasive lock free stuff, all of these are pretty out of place

[white valley]

you could also go for an alternate timeline kinda thing, like, "what if these 80s companies continued making new tech and x86 never caught on"

[twilit smelt]

The end goal is to run on amd64 at some point and be genuinely useful (although not uniquely so in any way, obviously) and not just larpy and dumb

[white valley]

dont you think it might lose some of its charm by being more "professional"?

[twilit smelt]

So I want to have an IO system that is designed with awareness of plug n play and power management and stuff so that later I can do that stuff on real people computers

[twilit smelt]

That ship has long sailed

Most of the ppl who were following this project since the goofy lua emulator in like 2018 lost interest bc it got "too professional" and that was still during old mintia

[white valley]

damn

i think it lost most of its charm when you ditched the LIMNstation name

[twilit smelt]

That name was dum

I have not once regretted that lol

[mortal thunder]

are you going to use the System V ABI in the kernel/userspace or are you going to make up your own calling convention?

and also do you have plans to also port to 32-bit x86 or just x64

[white valley]

why would he do that

apart from like

a posix compat layer

[mortal thunder]

why would he NOT do that

[white valley]

cuz it doesnt fit the project goals?

[mortal thunder]

and porting to amd64 by creating your own call conv does

[white valley]

yup

you got it

[mortal thunder]

you dont have to though

amd64 isn't a platform that doesn't already have a call conv

you can just use that

[white valley]

"amd64" doesnt have a call conv

[mortal thunder]

no, it has several

there's the system v abi call conv, and the ms fastcall call conv

[white valley]

dude i know

[mortal thunder]

afaik

[white valley]

im just saying the calling convention depends on the arch

[mortal thunder]

ok

[white valley]

not the other way around

[mortal thunder]

so why do you think it's against the project goals to use an existing call conv for amd64

[white valley]

because he's inventing all of his own stuff?

[mortal thunder]

one arbitrary limitation something like this would entail would be that you couldn't link jackal and C code together

although meh

that depends on the xrsdk linker supporting elf objects primarily

[white valley]

thats why i said he could do it for a posix compat layer or smth

[twilit smelt]

I mean

I like to invent my own stuff but there's no reason to arbitrarily use a randomized calling convention just to be Different

[green pelican]

sysv is great aside from not letting you use the carry or direction flag as an error bit on returns

although you can at least return 128 bit structs in rax:rdi so its not all bad

[coarse current]

not on ia32

like struct { int t; }; becomes an implicit first argument

[green pelican]

ouch

does anyone on this server actually have itanium hardware though

[coarse current]

(but there are other calling conventions...)

What

ia32 is intel pentium

[green pelican]

oh you mean x86 not itanium

[coarse current]

32 bit x86

yeah

[green pelican]

4head on my part oops

[coarse current]

itanium is ia64

[green pelican]

i forget intel calls it that

[coarse current]

yeah, the naming is confusing

[green pelican]

also making an os in 2025 and targeting 32 bit as anything more than an afterthought is shooting yourself in the foot a little

[coarse current]

my os fully supports it, and I had intentions to do it from the beginning

but i started with 64 bit stuff and went to 32 bit later

[coarse current]

if only itanium was supported by limine...

[green pelican]

at some point im going to have to add sparc support to limine and im not looking forward to getting a changeset that big merged lol

[coarse current]

but there's no uefi for it

[shut belfry]

openfirmware

[green pelican]

openboot is written entirely in forth so it must be good

[coarse current]

i mean if limine gets support for openfirmware, why not add powerpc support as well

[mortal barn]

if Limine ever gets PPC OpenFirmware support, I'd port it to the Wii

[coarse current]

Wii is 32 bits?

[shut belfry]

Yup

[coarse current]

I mean I though that Limine boot protocol was 64 bit only...

[sterile frost]

yeah but limine works on 32 bit machines

linux works on 32 bit machines

multiboot2 supports ppc

(i think)

or it might have been mips... i dont remember

sorry for misinformation

[shut belfry]

mips

[sterile frost]

but the first two are still true :^)

[coarse current]

Also, does Wii have openfirmware?

Also, I think a more interesting target is Wii U

It's afaik it's 3 Wiis bolted together

[mortal barn]

not yet

a port of OpenBIOS is being worked on

but no, not yet

[mortal barn]

it's actually kinda more interesting

it's more of "We took 3 Wiis, gave them performance enhancing drugs, taped them together, then gave it 2GB of RAM, and a competent GPU"

(the Wii had only 88MB, and a custom, not very good, GPU)

[teal trench]

so 1 wiiu = 3 wiis = 3 * 2 gamecubes?

[mortal barn]

in terms of CPU horsepower? close enough yeah

[teal trench]

nice

[mortal barn]

although at each step they bumped the clock speed substantially

GC -> Wii was 1.5x (486Mhz -> 729MHz)
Wii -> Wii U was ~1.75x (729MHz -> 1.2GHz)

but... close enough

[twilit smelt]

i am implementing IO enqueue for mintia2 IO system (the real one not the one im throwing away)

there are four important data structures

IoPacket: describes an overall ongoing IO request
IoLocation: an element in a list anchored on an IoPacket which contains context for a member of the target device stack. may or may not allocate one, its not required if you have no context that needs to be looked up after enqueue time (simple filter drivers would not require one of these)
IoTrampoline: contains the parameters for the IO dispatch routines; you modify this in your driver to direct the enqueue routine to the appropriate next device w/ appropriate next parameters after you return. the initial one is stack-allocated but extra ones can be allocated dynamically for fragment packets
IoDevice: a member of a device stack and potentially attached to one or more planes of the device tree

the lifetime of a dynamically allocated IoTrampoline would be really brief, only living until the end of enqueue time, so its probably more than sufficient to have a cache of like 8 of them

and almost never hit the actual heap

along with probably a cache of like 20 and 40 packets and locations respectively

the IoTrampoline isnt the same as the IoPacket bc saving space, it contains request initiation information that a physical device might be able to do a more compact representation for in its per-location context (for instance a disk that only supports 32 bit LBAs can store that rather than the fully-qualified 64 bit byte offset; or a serial port doesnt have to store such a thing at all bc it makes no sense)

both are always stack-allocated for synchronous non-fragmented IOs which will be the most common probably

also i might embed the first IoLocation inside the IoPacket just bc its gonna be exceedingly common to have at least 1

[twilit smelt]

also im gonna try to have the whole thing be procedural rather than ever directly setting stuff inside these system-defined structures

im aware this will have some performance hit but if i want my drivers to be as cute as iokit's and avoid the gnarliness of NT's this is the only option

i can use macros for certain things if they only set/get fields whose offset is guaranteed to never change

frinch toste

[warm pine]

you've got zone allocator, the time has perhaps come to extend it with slablike features and magazines

[twilit smelt]

perhaps.

[warm pine]

i like the new developments in your io subsystem plans btw

i can't copy them (too much runs at dpc level on my side) so you know it's genuine

[twilit smelt]

btw im allowing completion routines to re-enqueue the same packet, potentially to a completely different device stack, and then return OS_STATUS_MORE_PROCESSING_REQUIRED which causes the higher level completion code to drop what its doing and leave the packet alone and just return

the location for the guy who returned that status code as well as everybody above him stays intact

and next time completion runs through, he'll get called again

so in this way you can move bidirectionally up and down the device stack

bc the locations are dynamically allocated i dont need to allocate a whole new packet if i target it to another device stack

i can just kinda do it and itll work and i'll receive a completion callback later like normal

[warm pine]

yes, it's really quite flexible, i like it a lot in that regard

[twilit smelt]

this whole thing will almost certainly require more cycles than the old mintia io system (barring jackal codegen advantages)

but drivers will be wayyyy prettier probably

ideally ill be able to come up with sufficient abstractions for it to be iokit level pretty

[twilit smelt]

in particular the trampoline structure needing to be dynamically allocated for associated packets might end up being a scary bottleneck but its basically necessary due to the absence of a location structure until its actually created, not to mention it should lower memory consumption overall

the alternative is to put the stuff thats in the trampoline into the packet header

and then let that just waste some bytes while the io is ongoing (since its useless after enqueue time)

in any case this is transparent enough that i can switch it up later if i want

[warm pine]

with magazines or similar caching allocator it should end up with the limiting factor being the cost of a function call in most cases

[twilit smelt]

I got the early implementation of this new scheme pushed before I went to bed last night

Completely untested and highly intricate so it's probably broken in 10 ways but still representative of how it'll be

[twilit smelt]

im going to some lengths to eliminate tricky rules

one of them was that you cannot associate any IO packets with a parent until after youve ruled out all error cases

because there wasnt necessarily a good way to tear down an associated packet

but i came up with a way

basically i just leave it associated and leave it deferred-enqueued at the time that the parent is failed

the parent packet is left intact by the reference taken out by this child

when the child goes to be enqueued, i notice that the parent's enqueue-time status was something other than PENDING (which means it was early-completed either in success or in failure), and then instead of going thru and enqueuing the child i just complete it immediately

with the same error status

idk if this makes any sense to anybody other than fadanoid who has been like following along closely for the last few yrs of conceptual development on this stuff lol

but tl;dr drivers will be able to look a lot cleaner bc they wont have to be as meticulous about this particular error case

[twilit smelt]

this works specifically because the packets arent actually set going inline with each driver's dispatch routines

a whole packet is processed before any of its children are

so any enqueue-time non-pending statuses are known to all the children before the ultimate caller of IoEnqueuePacket receives them

this is important bc of the lifetime of the parent packet

if you receive anything other than OS_STATUS_PENDING from IoEnqueuePacket, you can assume the packet is fully back in your custody (assuming you set it so that it isnt automatically freed upon completion. if you did then its just gone and obviously you cant touch it again)

in particular, you know there are no child packets that depend upon it still out there asynchronously doing something

so you can free the packet if you want or do whatever with it and its safe

[warm pine]

i'll peruse it in due course

[twilit smelt]

Lmk if you notice stupid stuff

[twilit smelt]

the io registry planes in xnu are not trees

they are DAGs

something to note

just as a parent can attach to multiple children, a child can attach to multiple parents

cycles i assume are forbidden although im not seeing any logic that checks for them

[twilit smelt]

one example of this in use is the RAID driver

an AppleRAIDSet device object is a child of multiple parents (aka "providers"), which are its underlying disk devices that form the set

lolz!

this could have just been return super::attach( provider );

how silly...

[green pelican]

i bet somewhere in the history of that function there was a debug log on line 124

[twilit smelt]

iokit is difficult to understand bc of oop spaghetti

by that i mean the sources of iokit itself

iokit's drivers seem to benefit more than they suffer

not to mention an almost total lack of comments

i hate people who are like "dont write comments. write self-documenting code." and then it turns out what they mean is something like this where the individual operations are obvious bc of well-named variables and stuff but its much much more difficult to piece together the high level theory of what this is actually accomplishing

which could have been explained in a comment somewhere but wasnt

the version of this method from mac os 10.1 is considerably simpler than the modern one lol

ive found studying older versions of systems can help a lot with understanding the newer stuff

there are fewer details obscuring the overall architecture ig

once u understand that then its easier to go back to the more complicated thing and fill in the details

[white valley]

is this the old version

of the thing you sent before

[mortal thunder]

i agree

[twilit smelt]

Yes

The substantially less brain folds version

Top was the implementation of IOService::_adjustBusy in modern xnu (2024) and bottom was in Mac OS 10.1 (2002)

the year I was born

!

[white valley]

you're stupdi cuz they said // a multiply attached IOService can be visited twice and that explains pretty much the entire function which is already very self explanatory

i love how theres a single comment and it means like nothing

may as well not be there

[twilit smelt]

I'm trying to understand the big picture implications not the little mechanical trivia

[white valley]

i get what it's doing but not why

[twilit smelt]

Its difficult to follow bc there's all these asynchronous notifications and stuff which are all indirections into stuff that's difficult to find

Like im still unsure what this busy count is even for

It's not a reference count because there's already one of those

[white valley]

isnt there more a explanatory documentation

[twilit smelt]

I read like all the iokit docs already lmfao

[white valley]

also this if(x) do { thing is the worst C slop ive ever seen

who tf does that

[twilit smelt]

this is how it's documented on apples website

[white valley]

is there a documentation page for the busyState itself

[shut belfry]

I see no issue

[twilit smelt]

well it's a do while loop

so presumably they're just trying to eliminate an extra level of indentation

I still wouldn't have done it like that tho

[white valley]

judging by the code they couldve just done

if(!x) return ...;

and then put the do while after it

[twilit smelt]

yeah

that's what I tend to do

[white valley]

great minds think alike

[twilit smelt]

I still need to read this one

[white valley]

wait why is it recursing here

thats still the adjustBusy function right

[twilit smelt]

I do not know the meaning of that flag

I'll find out another day, for now I must sleep

Also I don't rly wanna understand it toooo hard bc then I'll inevitably just duplicate it while doing my own thing

I have my own ideas for how to do a pnp friendly IO system with an iokit esque driver model

They don't seem to line up much with the actual iokit impl

[white valley]

cool

[twilit smelt]

Which isn't to say they're better but I'll learn more if I try them and fail organically than if I just rip off a robust one that's already real

[white valley]

true

maybe thats why i failed

[mortal thunder]

you can also do else for and else switch

[white valley]

i tried to go straight into compiler dev always trying to do the best possible thing instead of just going with my ideas and iterating until it was good

[mortal thunder]

but i agree they should've just done if (!delta) return result;

[white valley]

you can do a billion combinations of those

it just doesnt help readability

[shut belfry]

eh occasionally it can

[white valley]

if your coding style is based on occasions, it probably isnt very good

[twilit smelt]

I like the naming in iokit but I dislike every other thing about the code style

It's interesting how it seems to be almost an echo of a new kernel that they would have liked to make if they had time bc it's internally consistent in style and design but totally mismatches the mach and bsd parts

wonder what growing a matching kernel around iokit would look like

would be written in c++ ofc

I do have to sleep tho bye

[white valley]

good night

[mortal thunder]

gn

[white valley]

going to sleep at 1 am be like

i fucking missed an exam today cuz i was like "oh the biology exam tomorrow is at like 14 so i can just sleep late and skip the first half of school"

completely forgot about another exam at 9 am

[mortal thunder]

i had to miss a test yesterday since i had a practical exam in driving

[white valley]

damn

at least you had to miss it

[shut belfry]

my condolences

[white valley]

i was victim to my own lack of memory

[mortal thunder]

well i passed

so its fine

or were you on about dwl

[mortal thunder]

true

[shut belfry]

no about driving

[mortal thunder]

oh yeah i passed

[shut belfry]

my condolences were for needing to drive

[mortal thunder]

ah

strictly speaking i don't "need" to drive, but it's going to be useful

[white valley]

when the russians invade you're gonna have to floor it to save your family anyways

better to learn it now

[mortal thunder]

That's true

although i think there are going to be checks at the external borders if we get invaded

we only barely entered schengen so the borders can be brought back in full force relatively quickly

[white valley]

just cross the border to bulgaria and it should be smooth sailing from there

[mortal thunder]

yeah that's what i was just on about

well i was thinking of crossing to hungary but same idea

oh but you know what we do have

mountains

the russians will have a hard time conquering us on the other side of the carpathians

block off all the roads once they reach the mountains, fuck em

[white valley]

honestly i wouldnt even worry about it now

[mortal thunder]

yeah kinda

[white valley]

if russia does invade it'll probably in a few decades

when they recover from the ukrainian war

[mortal thunder]

the only thing russia can do at this point to romania specifically is send drones and missiles

not a full ground invasion like in ukraine

poland and the baltics are severely more affected because they border russia and belarus

but romania's got the entirety of ukraine as a shield

[white valley]

i wonder how well finland would do

against a possible invasion

[mortal thunder]

same

[sterile frost]

if( expr) { is unhinged

who tf codes like that

[coarse current]

I do...

[acoustic sparrow]

people who type very quickly and dont reread their code

[sterile frost]

last time i checked your code didn't look like that

[hybrid condor]

Something's off with the first screenshot

I'd say you sent two different functions

[sterile frost]

yeah, the first function is IOService::terminatePhase1 and the second one is IOService::_adjustBusy

[hybrid condor]

I think this is just a progress indicator for the matching process

[coarse current]

Yeah, I misread the message

I have clang format

[warm pine]

it's a struggle to find much information on what motivated the design

[shut belfry]

Email Avi Tevanian

[warm pine]

https://www.geeklair.net/~dluke/PCIdevice_tutorial.txt some old mailing list posts from Godfrey van der Linden who appears to have been the main architect of iokit are found here

[shut belfry]

https://lists.apple.com/archives

I'll be damned

https://cgi.cse.unsw.edu.au/~cs9242/06/lectures/09-IOKitx6.pdf

[warm pine]

snap

i was just about to link it

it's reassuring that device teardown was just as mind bending for them as for me

[shut belfry]

https://arstechnica.com/civis/threads/developer-how-to-write-an-iokit-ethernet-driver.793112/

[green pelican]

oh man that code is rough lol

something about array elements being accessed like that also really irks me

at least the naming isnt too bad

lemme see if i can dig up some symbol names from oracledb, those were really rough

[green pelican]

lxhmcnv, sltsmnt, lxgt2u, lemfaf, lxuCpCplrStr, skgpospidstr, and lxsCpkgpospidstrtr from quick glance

10/10 symbol names

[acoustic sparrow]

holy shit what

[green pelican]

oracledb despite being an oracle product and apparently a nightmare to work on is a rare story of long running engineering success in the buisness world

the same 150-ish people have been working on it for nearly 40 years

the core oracledb team has had a single public job opening in the last 3 years

[white valley]

i wonder how much time it would take to rewrite it

[green pelican]

its around 20 million lines of C, assembly, and C++ for the core database

they have zero unit tests but achieve nearly 90% test coverage using nothing but end to end and integration tests

plus the mountains of perl, java, shell scripts, and other stuff for the surrounding ecosystem

oracle rac is 500mb of perl and shell scripts that somehow works

it also ships with debug symbols, which is a rarity these days

a couple more good symbolskdstf001010100001000kmP hcsXQryObjCpTrvrDspForXAutoExFnPro

alot of functions are also prefixed with the names of people who work there which is certainly an interesting style

anyway yeah funny symbol names 10/10

[acoustic sparrow]

ahh that makes sense

ig

[acoustic sparrow]

damn

i have also read its not a very fun codebase to work in though

[green pelican]

yeah macro hellscape that breaks all tooling and has 3 day test runs

[acoustic sparrow]

yeahhhh

[white valley]

"hey, who the fuck renamed hcsXQryObjCpTrvrDspForXAutoExFnPro to hcsXQryObjCpTrVrDspForXAutoExFnPro? it broke half the assembly files?"

[acoustic sparrow]

i suspect the first three letters are initials

also they have tests

so so many tests

[digital pivot]

is it really that huge

why

[green pelican]

it does alot of things

[digital pivot]

postgressql also does a lot of things and isnt 20 million loc

its like 1.3M lines of code

[green pelican]

oracledb was written before anything was actually standard so it includes all kinds of stuff that postgres just doesnt need to include now

[digital pivot]

idk it's not easy to justify a difference of 19 million

its a looot

[green pelican]

if it aint broke dont fix it ¯_(ツ)_/¯

also their codebase will contain all kinds of government required auditing support code that stuff like postgres just doesnt need

they generate an insane amount of audit logs that are needed to comply with various government agencies

death by a thousand cuts kind of deal where every client wants one specific feature and eventually the codebase grows alot

[twilit smelt]

Oopsie

I got lost ig

[twilit smelt]

i found a recording of the original wwdc 2003 presentation

uploading it to yt rn

ripped off a dvd the internet archive had

https://www.youtube.com/watch?v=HgOumQRtc_0

[twilit smelt]

He uses the word "mind bending" lol

[twilit smelt]

Woahh

I just realized my packet enqueue scheme lets you go up a device stack as easily as it lets you go down

Gonna be suuuper useful for pnp

[mortal thunder]

how the fuck do people read that code

the second one maybe "hcs X Query Object Copy Traverse Display For X Auto Extra Function Prototype`?! but the first one I cant decipher

[warm pine]

Extraordinary synchronicity

[twilit smelt]

and thats probably what he said when they got device teardown working reliably.

[twilit smelt]

things are slowly coming together

in my head

im glad i havent rushed ahead with anything other than the basic packet enqueue stuff bc gears are definitely still turning

[twilit smelt]

wowza

something clicked suddenly

WHICH IS:

you only need to worry about synchronization issues for requests entering the device stack at the top level

in the case of iokit storage drivers, the top level is always IOMediaBSDClient

so i went to that source module and bingo

its the junction between the BSD layer the iokit storage drivers

and is full of synchronization goodies

i also realized my io requests have to be polymorphic

targeted toward either an FCB or a device object

[mortal thunder]

why can't the device object have a single FCB associated with it

[twilit smelt]

basically bc itll be redundant info

i want a device object to only have an FCB if it is being exposed through the namespace

this FCB will be managed by a pseudo filesystem driver (think of it like devfs) that accomplishes basically the same tasks that IOMediaBSDClient does in iokit

basically making sure that the device stack doesnt disappear while the request is inflight

a device stack will actually be able to disappear from underneath a filesystem mounted upon it, just not while an io request is actively ongoing

basically by the filesystem only accessing the device thru the FCB, and the FCB just gets "detached" from the device stack when it goes away

further attempts to communicate with the underlying device will yield IO error statuses

[twilit smelt]

if a device your driver is managing physically disappears then the bus driver will generate a termination packet that travels up the device stack and its your job to cancel any inflight IO requests with an appropriate status code asap (and prevent any new ones with the right error status as well)

so that the memory can get cleaned up promptly

a lot of this explains how iokit was seemingly magically able to call up and down the device stack without ensuring at each level that the next still existed and whatever

basically the guarantees were already made at a higher level

which ofc makes sense, its the only logical explanation for how they were doing that

but its nice to find the component most directly responsible for doing that

[twilit smelt]

cool timeline of the earliest mac osx (rhapsody) development

in 1997

thats actually wild that they ported nextstep to powerpc and got the blue box (classic environment) running on it in literally 3 months

tbf the blue box pre-existed from Copland, it was the only thing of Copland that survived iirc

something i knew but didnt pay much attention to was that the development of OSX was a nearly NT-level undertaking

they werent quite developing a 99% new modern OS from scratch from the ground up as quickly as possible (NT was the last time anybody ever succeeded at that (Copland was the last time anybody ever tried in general)) but they probably wrote just as much code or more

[mortal thunder]

I think Apple had been suffering under similar circumstances (they were stuck with the 68000 while MS was stuck with 16-bit x86)

[twilit smelt]

Godfrey van der Linden vs Darryl Havens death match

venue: mintia2 kernel

[shut belfry]

Have you considered reaching out to them?

[twilit smelt]

i feel like ive bothered enough cool boomers and have used up my boomer bothering budget

if i bother more ill become known among the boomers as a notorious boomer botherer

dont want that to happen

[twilit smelt]

its crazy ive been at this for like 5 yrs and im only just now getting to concepts that are younger than i am

well, almost

they were at least being presented on while i was a baby

rather than 10-30 yrs before my birth

this exact io system design im about to implement at least will be considerably younger than me

but it uses concepts that are quite a bit older than i am, just in a new combination

[twilit smelt]

cool covers i saw on bitsavers

[twilit smelt]

im writing the quantity of comments that i wish iokit had

the biggest one there is for a thing i thought of in the shower that wont actually be needed for some time

allegedly im committing a cardinal sin of over-designing things before i actually get there but i dont have the skill issues of tech influencers who say stuff like that, so im p sure itll all fit together nicely

[raven drift]

I don't think any level of skill saves you from that issue

[twilit smelt]

well this entire kernel is already an exercise in "doing stuff before i need it"

[raven drift]

It's fine to design stuff in advance and if you're doing this for your own enjoyment there's also little cost associated with it

but it's still unlikely that the final design after gaining implementation experience will look anything like what you designed initially

[twilit smelt]

well thats the thing, i already did a big fancy kernel that implemented all these features (page swapping, async io, driver stacking, etc), and it took me like 3 yrs and didnt rly look anything at the end like it did at the start

im basically just doing the same thing again but with more brain folds

i feel ive already put in the 90% learning cost which is learning how to structure stuff overall which forms the large majority of the effort bc failing at that causes you to redesign and rewrite big swathes

especially with page swapping lol

but we'll see how this all pans out, im still optimistic although itll take a long time

im already 9 months deep

[raven drift]

Yeah, it's true that you'll need to do less redesign in that case but that's not because other ppl have skill issues, it's rather because this is already your v2 or v3 ;D

[twilit smelt]

true!

i was joking about that part tho

i just like saying mean things about tech influencers

also this time im doing tonnns of work to limit kernel stack usage

the IO enqueue mechanisms, object deletion, and other stuff are built around work lists, whereas call-through is used for the same thing in other kernels

the goal is for the maximum call depth to be deterministic and like less than 10-20

so i can use a single page of kernel stack

[green pelican]

everything related to computing was invented before 1970 really

its all been remixes of the same concepts and ideas since then

[twilit smelt]

not exaaaactly

[raven drift]

That's not really true. Many designs that were reasonable in 1970 are not reasonable anymore

[twilit smelt]

most lock free techniques are newer than that for instance

[raven drift]

In 1970 we didn't have SMP, large multi-level caches, asynchronous devices etc

[green pelican]

brb furiously googling when the first cpu with cmpxchg was created

[twilit smelt]

nothing even uses cmpxchg

at the hardware level

its all ll/sc since the late 90s at least

[raven drift]

created != used

[twilit smelt]

even on x86 its turned into ll/sc pairs at the uop level

another RISC victory

[green pelican]

can i adjust my statement to like 1979 or so

[raven drift]

if you want to ask when modern systems designed started, look for the first devices that used command queues in RAM instead of register interfaces

and these probably appeared in the mid 90s

[twilit smelt]

probably earlier in the server and mainframe space

[raven drift]

up to that point you'd still drive a device by writing a bunch of registers on the device itself

[twilit smelt]

i was shocked at how modern (in nature) the capabilities of like the early 90s Alpha mainframes were, it was just slower

[green pelican]

huh, i always though cmpxchg was picked mostly because it was easy to implement in hardware

the more you know

[twilit smelt]

no, ll/sc is MUCH easier to implement in hardware

[raven drift]

yeah

[twilit smelt]

at least in smp systems

[raven drift]

ll/sc is literally just: once I have a cacheline in exclusive mode, i can do whatever i want w/o other CPUs seeing it

[green pelican]

dont most atomic instructions have to be implemented somewhere in the cache controller rather than the ALU or am i mistaken on that as well

[twilit smelt]

yeah it basically rides on the cache coherency traffic youre already doing

no extra cost ish

[twilit smelt]

well theyre all decomposed to ll/sc sequences on x86

so no

[green pelican]

i need to brush up on my hdl quite badly, its a bit of a weak spot for me

[white valley]

the hours ive wasted learning verilog will never come back

fuck HDLs

[green pelican]

i have a fpga dev board i feel i need to use it more

the fpga is to small to synthesize real™️ stuff but too large to ever fill with a personal project

[raven drift]

and forward progress can be guaranteed by letting load-link refuse to write back the cacheline until X instructions have been retired

[green pelican]

i swear no matter how much i stare at atomic code and write my own it never quite makes sense why it works

[twilit smelt]

my third eye opened when i implemented ll/sc by simulating a MESI cache coherency protocol in software

for my smp emulator for my toy arch

[raven drift]

imho acquire/release semantics are quite intuitive

[green pelican]

i get the C++ side of things mostly, its just load store reordering relative to an instruction

[raven drift]

the c11 memory model is very easy to understand compared to everything that came before it

[green pelican]

its the actual atomic algorithms beyond quite basic cas loops that elude me somewhat

[raven drift]

but yes, code that needs stronger barriers than acquire/release is not that easy to understand

[green pelican]

despite implementing a lock free mpsc queue, rcu, and a whole pile of lockfree stuff i just never quite get why it works

i know enough to be dangerous which is perhaps the worst place to be with this stuff lol

[raven drift]

for example, sometimes you want to write code that first publishes data and then checks if it needs to ping consumers

this goes beyond just acquire/release

and may require a full memory barrier depending on how exactly the code is written

[twilit smelt]

the implementation of io registry planes in iokit is strange

when you create a plane called for instance MyDumbPlane it will create the strings:
MyDumbPlaneParentLinks
MyDumbPlaneChildLinks
and then it uses these as keys into a global OSDictionary (hash table) which yields an OSArray

im not quite sure why this isnt just two pointers

[white valley]

what is OSArray

[twilit smelt]

its a dynamic array

in libkern

which is their kernel space C++ runtime

[white valley]

so pointer + size + cap?

anyways if OSArray can be relocated by resizing maybe thats why theyre using those strings?

[twilit smelt]

no the actual OSArray object has a static location, the buffer is what moves

itd break its membership in the dictionary if it itself could move

[white valley]

could the hash table impl be moving it

[twilit smelt]

its not

[white valley]

hmm

i would say "maybe it's so that you dont have hanging pointers and fail when trying to use those keys instead" but like that makes 0 sense in this context

im at a loss

[twilit smelt]

the only thing i can think is that it has some introspection purpose

oh wait

i think i get it

its not global after all. this OSDictionary is per io registry node

its to avoid storing links for all possible IO planes within each registry node, so that you can create an arbitrary number of them at runtime

a plane btw is like a whole node graph

a DAG

used to model relationships between devices

okay this is all making more sense now lol

good lord this is memory-hefty though

[twilit smelt]

i got confused because C++ has the same syntax for accessing globals and class members lol

and i was reading it with C brain

also im reading the mac os x 10.3 and modern iokit sources side by side to see how they changed

terrifyingly, the 10.3 one had a complete rwlock implementation special for the io registry

by nowadays it uses a generic one exported by xnu

[twilit smelt]

i found maybe the most repulsive reddit comment section in history https://old.reddit.com/r/linuxmemes/comments/vq6vtq/xnu_sounds_cool_though_ngl/

[white valley]

it's just copypastas lol

[twilit smelt]

exactly

the repulsive part is that those are somehow real people who spent their time posting inane spam for fun

and not bots

[white valley]

lol

honestly it's like the lowest effort content ever

just CTRL+C CTRL+V

they dont even change the damn thing

[warm pine]

is it really though

[white valley]

who cares

[warm pine]

there's something to be said about people who argue names

[twilit smelt]

i had a funny idea for dequeuing timers safely

such that like once you dequeue it you can be sure nobody will touch it after the dequeue call returns (and it can be deallocated or whatever)

for context i have per-cpu timer trees and a per-cpu timer expiration dpc

basically when i go to dequeue a timer and the caller specified that he'd like it to be completely quiescent after the dequeue (which has to be specified bc sometimes it doesnt matter so much, like if youre just dequeuing and re-enqueuing to change the timeout and arent about to free the timer or smth)

if it's enqueued to the current processor, i can just remove it from the timer structures safely and return. this is fine bc i know the timer expiration dpc isnt currently running because IM running.

if its enqueued to a remote processor, i can migrate the current thread to that processor and then dequeue it lol

and then just return

i think a similar/identical thing would work for quiescent DPC dequeue

so then i dont need a DPC barrier bc i can just do this

the "i know the DPC isnt running on that processor because IM running on that processor" trick

[twilit smelt]

also i can make it the caller's responsibility to decide whether the timer callback or DPC routine need to be executed

i already return FALSE if the object was not actually enqueued, TRUE if it was and i dequeued it

with these extra guarantees, this can be used to know for sure whether the routine executed or not

if it returns TRUE and you need the routine to execute (maybe it frees up some resources or something) then you can explicitly call it yourself

[twilit smelt]

nvm, does not work

[twilit smelt]

for timers and dpcs both

you need to dequeue them to ensure that a dispatch will not begin on another processor in the future

and then do a full dpc barrier to ensure that a dispatch is not ongoing in the present

this is relevant especially for like driver unloading

[twilit smelt]

i havent been charging full quota for IO packets bc itd make the overhead of allocating the packet locations and stuff even more unbearable

but i should charge at least quota for the packet header

so that Something is accounted even if its not the full thing

its the piece with the longest lifetime as well

i could also completely forego it and just make outstanding async IO requests their own resource accounted separately

[twilit smelt]

https://open.spotify.com/track/2T9Qu8V3gAMKgMdcuZfs6B?si=bf3a7d9d96c44300

[twilit smelt]

kind of annoying playing with an old mintia disk image and going like "man i wonder if ill ever be able to make something like this" and then remembering i DID make something like that and i had to THROW IT AWAY because 15 YEAR OLD ME thought itd be a good idea to design the worst programming language in history

at least im making the most of the opportunity and im not just rewriting the old one 1:1, flaws and all, like the original plan was to do

[twilit smelt]

also iokit is really cool

i love the flow of IO dispatch and the driver matching process

[twilit smelt]

good lord thats a big file

[twilit smelt]

am i misreading this or is this redundant

[digital pivot]

lol

iokit?

[twilit smelt]

yeah

i like the overall design but i feel like an obsession with quality was missing during the implementation lol

[dense vigil]

is it deprecated?

Also, what does that sentence in the overview even mean

[twilit smelt]

its talking about the userspace half of iokit

the iokit framework

[dense vigil]

"such drivers and nubs through the device-interface mechanism"

[twilit smelt]

thats just a typo

[twilit smelt]

yes in the sense that youre not supposed to directly use it anymore, driverkit iirc is a userspace driver framework that youre supposed to use instead

but they didnt get rid of it they just privatized it

[dense vigil]

whats it supposed to be

[dense vigil]

ah

[twilit smelt]

confusingly the new "driverkit" shares a name with nextstep "driverkit" which was the father of iokit

no relation

so it went driverkit -> iokit -> driverkit (different one)

https://www.nextcomputers.org/NeXTfiles/Software/OPENSTEP/Developer/DriverKit/DriverKit.pdf

nextstep driverkit docs

probably they did a new one for OSX instead of reusing driverkit because it wasnt plug-n-play ready

or power management ready

driverkit doesnt seem to have had any concept of the IO registry which is integral to how iokit implements those things

so it wasnt suitable for a consumer OS

if they had some compelling reason to maintain nextstep's existing driver base then they would have had to retrofit those features onto driverkit

like they had to with NT

which would have made a horrific mess (like it did in NT)

luckily they were putting it on apple machines that couldnt make use of any of the existing nextstep drivers anyway so they were able to just do an all-new IO system lol

prob why its so clean compared to the modern NT one

[twilit smelt]

WHUUUUHHHHHH?!?!?!?!?!?!!!!!!!!!!??!???!?!?!!!!!

just the way they roll.

[acoustic sparrow]

also its apple so they can just tell developers "well fuck you you now have to write your drivers against the new api" :^)

[twilit smelt]

thats a lotta globals

landy wang reaction: 🤮

[digital pivot]

nt uses tons of globals tho

[twilit smelt]

landy famously de-globaled almost the whole memory manager though

partition objects

[digital pivot]

ah, in xnu all mm state is broken down in globals ?

vm_compressor - memory compression i assume

[twilit smelt]

yeah like it was in old NT

if XNU added NUMA support theyd probably scoop this all up into something similar to partition objects

and itd probably be suicidal-thoughts-inducingly tedious

[hybrid condor]

Remind me, sir, what was that?

[twilit smelt]

essentially just an object that contains all of the formerly global state from the NT VMM

[hybrid condor]

one partition object per NUMA node?

[twilit smelt]

and i mean all of it

yeah

each one has its own page lists with their own locks, they even each have their own pagefile

transferring pages between them is an explicit operation

which i dont believe is done in the numa use case, but theres another use case which is creating an airtight memory sandbox for some group of processes and transferring page frames is meant for that (in theory - im unaware if this is actually done)

[hybrid condor]

I see

Seems like Windows has been aware of NUMA for quite a while

[twilit smelt]

im not doing numa support but i have put my vmm state in a partition object

just because its extremely easy and low-cost to do from the ground up

and would be extremely tedious later

some of it still isnt numa-fied though like the kernel heap is still global

(cuz im not doing numa support)

but thatd be easier to do later

dedicate a big chunk of kernel space for a heap for each numa node and have them allocate preferentially from the closest heap

[hybrid condor]

What were you looking into in vm_compressor?

Planning to compress something?

[twilit smelt]

im just generally poking around xnu lately

especially iokit

memory compression would be cool but its not in the plans rn cuz theres already so much to do

[digital pivot]

memory compression is very nice

[twilit smelt]

i wanted plugnplay and power management in the mintia2 io system so i studied both modern NT and XNU's strategies and i liked XNU's better so i was gonna model it vaguely on that

[hybrid condor]

Yeah, pretty interesting, recently fixed a bug related to the compressor : an inversion occurs when a low pri thread gets stuck in the compressor while a high pri thread waits for the same page

I meant to reply somewhere else

[twilit smelt]

i like to believe the NT guys would have come up with something less clusterfucked if at all possible

[hybrid condor]

Is it really that bad there

[twilit smelt]

yeah theres like 50000 intricate rules for everything because of the way they had to retrofit it on the old IO system

the "WDF" (windows driver framework) was an attempt that came a bit later to shield people from this by wrapping the nasty native IO system for you

but its still not nearly as clean as iokit

to be clear i dont blame them

iokit was designed from a clean slate with all the features considered from the ground floor, while the NT people had to retrofit them onto a driver model that was already like 10 years old and could not be sacrificed

so they had the harder task by far

they probably did an okay job considering that lol

[hybrid condor]

I might be wrong, but I think they have a more modern framework?

[twilit smelt]

"all" is relative here btw lol

[hybrid condor]

UMDF

[twilit smelt]

i mean the big ones like plugnplay and power management had to be retrofitted such that the old drivers would continue to work perfectly whereas iokit always had them - both have had to add new major features since then im sure

[twilit smelt]

yeah

i havent compared this to driverkit (which iiuc is the macOS usermode driver framework) so i cant comment on the relative "cleanliness"

im just talking about the kernel mode side

[hybrid condor]

I believe it shifts development outside the kernel?

Starting with Catalina Apple moved to a new SDK, yeah

[twilit smelt]

iokit is still very pervasively in use for many drivers though right?

is the intent to phase that out completely one day

have all drivers in usermode

or is it just deprecated as an outward-facing thing but still has a long planned life ahead of it for apple's private use

i really should study these usermode driver models

but its a "later" thing

like i mentioned im already planning like 5000 new (to me) things for this kernel

its getting major second system effect already

if i plan even more stuff like usermode peripheral drivers w/ corresponding fancy framework or memory compression or something else i run the risk of not finishing it until after i graduate uni

and id really like to have it done by then

i can do that and then revisit it later lol

im realizing this is becoming less of a toy kernel and more a pretty substantial research project at least for 1 person

there are published research kernels that were less ambitious

from like the 90s lol

granted the ones im thinking of were all dumb microkernels by masters students who wanted to get it over with asap

but the planned/current feature list includes:

• page swapping, including of most kernel memory
• fundamentally async io system (including the filesystems)
• driver stacking
• name cache (like linux dirent cache) based vfs
• loadable/unloadable drivers
• plug-n-play, power management
• robust resource accounting
• scalable locking (turnstiles) with priority inheritance
• SMP w/ nontrivial scheduler w/ fine-grained locking
• fully preemptible (that is, spinlocks forbidden) outside the scheduler and primary ISRs, fully interruptible scheduler
• fully featured FAT driver & driver for custom journaling filesystem (TBD)
• once ported to amd64, an IP stack and linux compat layer will be written
• stacking window system for the native personality (linux one will use the typical wayland/whatever boringness)
• native userspace, including basic suite of command line utilities and desktop apps

plus lots of other stuff

these are all kinda hard

but i think i can do it in like 2 years

well. i can at least do the native bits in 2 years

the linux compat thing on its own (trying to run a substantial linux userspace, binary-compatible, on my own kernel) could easily take another year or two

[acoustic sparrow]

question: why journaling fs?

[twilit smelt]

bc if im doing custom everything way overengineered to an extent that literally anybody would advise against and severely doubt i would ever get done then that should include the filesystem too or its lame

[acoustic sparrow]

and not a b-tree FS or a log structured FS

[twilit smelt]

oh i see the question now

[acoustic sparrow]

(aka basically btrfs and f2fs respectively)

[twilit smelt]

i do not believe b-trees are on the same axis as the other things you mentioned?

i think you can have a journaled or log structured fs that uses b-trees

[acoustic sparrow]

i dont think so?

[twilit smelt]

why

[acoustic sparrow]

dunno about the details

[twilit smelt]

its just another on-disk structure

for tracking metadata

[acoustic sparrow]

by btree i mean using btrees and copy-on-write for everything

[twilit smelt]

oh i see

[acoustic sparrow]

which doesnt require journaling

[twilit smelt]

thought you meant like btrees for directories and storing file extents and stuff

[acoustic sparrow]

nono

[hybrid condor]

New system extensions are designed to be used everywhere possible. Essentially, kexts are deprecated ; you should be using system extensions (dexts)

[twilit smelt]

i like how this dodges answering my question kinda

[twilit smelt]

i designed a "mintyfs" i was gonna start implementing just before i decided to trash the entirety of old mintia

and it was super boring because i was afraid of both journaling and b-trees

so im kinda glad i didnt waste time implementing it

it was kinda an HPFS clone but with all the cool parts gone due to fear

a fancy new filesystem prob will not be part of the base system

ill probably just have a fat driver and an aisixfs driver like old mintia

and then move on

ill come back and do fancy fs later

cuz it deserves to be its own major project taking months

but theres no time for that in the current plan

[digital pivot]

isnt driverkit a user mode framework for iokit

so its based on iokit

[acoustic sparrow]

why aisixfs and not ext2?

other than NIH ig

[twilit smelt]

because thats how im currently formatting the test images

[acoustic sparrow]

ah fair

[twilit smelt]

the disk tool in the sdk can be extended with new filesystems though so i could switch to something like ext2

but yeah the NIH factor was the motivation here

aisixfs ofc is literally just a stupid fat clone but with inodes

why does it have inodes? bc aisix cloned the dumb BeOS vfs design where vnodes need a unique number and i didnt want to figure out how to make that work with a non-inode-based filesystem

so i added inodes

originally there were no inodes and it was just straight up a fat clone

[white valley]

cant you make a better FS

thats an ntfs clone instead

call it

limnfs

[twilit smelt]

mintyfs is already named to rhyme with ntfs

[white valley]

mentyfs rhymes more

and shows how manly your fs is

[twilit smelt]

counterpoint you are turkish

[white valley]

counterpoint the majority of your country voted for trump

[twilit smelt]

ouch! i mean your difference between "minty" and "menty" is probably not reflective of that in american english

most americans would pronounce those identically

not all though

[white valley]

the majority of your country voted for trump anyways, get destroyed libbie

[twilit smelt]

im unsure off the top of my head what accents would distinguish those but ik some would

[hybrid condor]

I answered "is the intent to phase that out completely one day have all drivers in usermode"

[white valley]

hmm

what about manty

surely the a doesnt get softened to an i too

[twilit smelt]

thats different but now it doesnt rhyme with ntfs

[white valley]

n is read like

[twilit smelt]

ik im messing with you lol

[white valley]

an

and manty is read like man

so you get like

the same an

instead of minty only having nty in common

unless NTFS is read like intyfs or something

[twilit smelt]

it is

[white valley]

wtf

are you sure youre not fucking with me

[twilit smelt]

why would it be pronounced differently

[white valley]

literally like, eenty fs???

[twilit smelt]

not eeeeee

[white valley]

i thought it was read like "an"

[twilit smelt]

i think we are suffering from not having a standardized way to communicate phonemes

luckily theres a solution to this

[white valley]

there is a standardized way

but i do not know it

[twilit smelt]

https://www.ipachart.com/

[white valley]

hmm i could also send a voice message

ok isnt it

æ

before the n

wait nvm

[twilit smelt]

/ɪn.ti.ɛf.ɛs/

pronunciation of ntfs

[white valley]

i give up

compiler dev is easier to make sense of than the pronouncations of words

[twilit smelt]

wow

put that in here

https://ipa-reader.com/

it does a great job of reading it

copy this "ɪn.ti.ɛf.ɛs" exactly

and press read

with [us english] accent selected

in the drop down

[white valley]

hmmm

it's more of an ı

but theres a bit of e in there

turkishly speaking

i see why it doesnt rhyme now

but that doesnt matter, how?
because aisixfs is a dum fat clone, wow.

now i shall leave, ka-chow

[digital pivot]

inversion here means priority inversion ?

interesting to see a case of it

i think will was afraid of priorit inversions in mm code

and implemented turnstiles , they are used in solaris and macos

[hybrid condor]

I have them too ; in fact, I'm using sleep with an inheritor

When another thread waits for a page it first checks a special hash table for a registered page worker (if one exists) - and if found the thread sleeps using an inheritor mechanism propagating its priority

[mortal thunder]

it's enn-tee-eff-ess btw, with the same e before the n as after the f and s

but i also think mintyfs and ntfs rhyme because of the -n-tee-eff-ess part

[twilit smelt]

i like mine better

[digital pivot]

interesting , is yours implementation open or not

[twilit smelt]

i just realized the 10 yr anniversary of me trying to make a compuer from scratch is coming up lol

well the 9 yr anniversary is coming up

thats the first attempt, which i still have (no i will not post it because its 14 yr old me code and its terrible)

ill note that it had fixed width 5 byte instructions

and it had an extremely bad language called "X" (which was a placeholder for a better name that i never came up with) which looked like this

glad osdev discord didnt exist back then, i might have embarrassed myself trying to post about this

this was so long ago it predates me regularly using discord at all i think

lol the language literally did not have support for expressions

it only did control flow, everything else required inline asm

i prob couldnt figure out expression parsing when i was 14

jackal would have blown my mind

[twilit smelt]

https://github.com/neozeed/Darwin_0.3/tree/main/driverkit-3

nextstep driverkit source code

apparently the very earliest source releases of darwin from like early 1999 still had it

it even has references to the unreleased m88k-based "NeXT RISC Workstation" (NRW)

@hybrid condor u might be interested to see the objective C based father of iokit

https://github.com/neozeed/Darwin_0.3/blob/main/driverkit-3/libDriver/Kernel/IOTokenRing.m

TOKEN RING!!!

#if defined(hppa)
#import <machdep/machine/pmap.h>
#endif

lol PA-RISC support

almost forgot nextstep ran on that

debug file left in https://github.com/neozeed/Darwin_0.3/blob/main/driverkit-3/libDriver/IOLogicalDisk.m.crasher#L357

seems absolutely ancient

much older than the other files

only half as many lines as its then-current version IOLogicalDisk.m

and theyre worse

[twilit smelt]

@warm pine minoca has iterative io enqueue

idk if i knew that and forgot

https://github.com/minoca/os/blob/master/kernel/io/irp.c#L1714

you might wonder how its checking a bit in the IRP to tell whether the stack level pended it

because that should mean custody has passed to an asynchronous context that could complete it at any moment (leading to the IRP being freed)

afaict its because an IRP is a full object manager object

and has a refcount taken out here

imo this is a mis-abstraction

because thats like the only real use of doing that?

and the extra overhead is quite severe

ofc you need a count of remaining child packets in order to defer completion until the last one has finished

but that's quite different from the full overhead of an Ob header and everything

[mortal thunder]

i agree, why would you do it like that

IRPs don't need object manager machinery as far as I can tell (other than the refcount possibly?)

[twilit smelt]

one cool thing you could do with it is actually allow people to have handles to IRPs

and you could selectively cancel an IRP or whatever, using this handle

but this is a relatively rare thing to want to do

[mortal thunder]

hmm true

[twilit smelt]

if you want to provide that functionality you could create a full object wrapper around a non-ob IRP structure, which you only use when theres an async request

and avoid the extra overhead on synchronous requests

where you just create a normal IRP

[mortal thunder]

that makes sense

[digital pivot]

they use the ability to wait for an irp object or to signal it with ob api

[twilit smelt]

yeah i just mentioned this

and i still think its weird they do it for every irp

because most of the time you dont care about doing that

vast majority of the time

even if you do, usually completion ports are still lighter weight and the superior option

so it doesnt win on performance and im unsure it even wins on elegance because completion ports are designed to be easy to use with worker thread pools whereas this api would be more difficult

so youd probably just use completion ports anyway and forego this entirely

if both existed

and if only this existed, itd be a worse system for it

[digital pivot]

have you heard of TPCs?

https://github.com/minoca/os/commit/b93d94b655c4df2e08262527ecbb541de28fa68b#diff-181c2b2e0ace3070687707efbdeda74ebac853930135a44378168f3cc3cc64ad

[twilit smelt]

its just their name for APCs it seems

which appears to only be what a special kernel APC is in NT

[warm pine]

Yeah that's what I immediately was struck by

I return the pended code instead

[warm pine]

But what if it's anyway completed? I'm away from home and can't look any closer at their code

In my case if an iop is pended then a return code must be used to prevent reentry to the processing - as completion (rather "continuation") of a pending iop restarts processing in opposite direction

[digital pivot]

they removed it the same day when added lol

[twilit smelt]

i think i know why

not having them from the beginning, they probably didnt take care to make certain things APC safe by raising irql to block them out

after implementing this they prob quickly realized "oh this just made like 5000 race conditions of a thread with itself which i dont feel like fixing so nvm"

[twilit smelt]

representing a DAG by giving each vertex a distinct set of parents and children is so convenient for locking

makes fine grained locking really easy lol

[twilit smelt]

https://github.com/xrarch/mintia2/blob/main/OS/Executive/Io/IoDeviceTree.jkl

this is turning out way too clean

im scared

only needing to lock one node to be able to get safe-to-use pointers to any of its relations is pretty cool

this is a good DAG representation. feel embarrassed i didnt know about this before

pretty basic data structure knowledge

[twilit smelt]

https://open.spotify.com/track/0udqTGVB1QIMtsZS4ojI6O?si=686e9ad13a3848c4

my guilty pleasure are these kinds of vaporwave loops

https://open.spotify.com/track/1pYGnUbMafdXkPWusR9SxS?si=ca0a177849ba4930

[twilit smelt]

if anyone here likes mintia but thinks vaporwave is cringe youll be disappointed to learn my personal soundtrack for mintia is almost entirely vaporwave-adjacent tracks and always has been

[white valley]

the music does give a kind of an 80s vibe

[twilit smelt]

the fact vaporwave is composed of 80s/90s samples and my brain likes to associate that with mintia is def not a coincidence

[white valley]

do you know lambda calculus

please say yes

[twilit smelt]

uhhh i understand it theoretically but ive never dived deep

[white valley]

well do you have any idea why this isnt returning false?

[twilit smelt]

are you sure thats lambda calculus and nothing else

[white valley]

it does let you define variables

as in

not lambda calculus variables

but like

you just name a lambda expression

[twilit smelt]

thats how variables in forth work as well

[white valley]

pair expands to (λx. (λy. (λf. ((f x) y))))
false expands to (λt. (λf. f))
true expands to (λt. (λf. t))
second expands to (λp. (p false))

theoretically bitadd false false should be returning pair false false

which should then be reduced to false by second

but it's not

this is extremely crucial cuz i need binary representations of numbers in order to make this fantasy arch not take 2 seconds per cycle

church numerals are too space and time inefficient

[twilit smelt]

if theres a moment i could have answered this question at all

its not this one

barely know that shit and ive been up like 24+ hours

[white valley]

damn

[twilit smelt]

https://open.spotify.com/track/339mwPMOqLVmDrIDz9wfZI?si=dde06a0a013c48e7

[white valley]

do you know someone who has expertise in this area

[twilit smelt]

the r/pl discord is full of people who are into that kind of thing

[warm mural]

just do haskell

[twilit smelt]

functional programming ppl are all super into lambda calculus

[warm mural]

it's lambda calculus but useful