Jim's Depository

If you have had to do something heinous in your code to avoid triggering a Swift compiler bug, you might consider…

#if swift(>=7)
#warning("Check if Swift bug is fixed and we can remove the '@unchecked Sendable'.")
#endif

In my case, certain presentations of indirect enums which reference each other (and that's totally legal!) trip a circular reference error in the analysis. The work around is to jiggle the order of your declarations, or dodge the analysis by marking it as an @unchecked Sendable.

The bug has been there since sometime in version 5, we are up in 6 now, so safe to say it isn't a priority. Setting a reminder that someday when you hit Swift 7 it is worth a review let's you forget about it now.

I know my daily readers have been wondering what's up these past 700 or so days…

• There will be no more OS work. I rolled a critical fumble on COVID and can no longer work with complex abstractions in my head. I was kind of hoping for a recovery, but it appears there will not be one.

• An OS which makes limited use of system calls and primarily operates by streaming requests from user space to the OS and responses make to the user space asynchronously was looking extremely promising and anyone looking to build one sadly only gets that anecdote from my work.

• Most of the entities which the user space communicates with are ordinairy, though trusted, processes in their own right, the kernel is quite small and really about connecting things. Breaking traditional OS subsystems off into their own processes has a nice synergy with high core count processors by putting more L1/L2 cache to work.

• Popular programming languages can be made to work in this environment, but there is a lot of friction. A language with builtin light weight concurrency is more ideal. I was in the middle of a sort of Swift subset which fulfilled that and looked very promising.

Not so OS related…

• I'm ok. I've been doing a lot of physical manufacturing skill work and exploring what I can create. I think I can do small software bits, but I have to finish them in one push, if I have to pick them up later it makes no sense to me.

• So I guess I'll take a little pivot here and start documenting small things and maybe just showing stuff I make.