Hm, why didn't they join https://www.redox-os.org/ instead?
Because there's nothing modern or experimental about Redox? At least not like what this is trying.
Theseus: A modern experimental OS written from scratch in Rust
131–140 of 153 posts
Re: Theseus: A modern experimental OS written from scratch in Rust
#132The name alludes to the Ship of Theseus, a thought experiment where, over the course of many repairs, every piece of a ship is eventually replaced. Given that, I found it interesting that this is applied to a novel greenfield OS effort, instead of a project to rewrite an existing OS in Rust piece-by-piece.
It's such a silly “thought experiment”. The simple answer is that “identity” is pseudoscience and does not exist; it's a man-made delusion created by the human mind to simplify reality and deal with it more easily. “identity” does not even apply to truly atomic particles, because there is no way to say that they aren't “different” in a next instance of time. There are far too many “thought experiments” and “quæstions…
Why is it silly to think about things that are man-made? You've clearly thought about it, otherwise you wouldn't have been able to write your comment.
Re: Theseus: A modern experimental OS written from scratch in Rust
#133Earlier quoted context omitted.
It was almost definitely HP Dynamo. (Edit: if you combine ideas from HP Dynamo, SafeTSA JIT-optimized bytecode, and IBM's AS/400's TIMI/Technology Independent Machine Interface, you get a better version of the current Android Run Time for bytecode-distributed apps that compile ahead of time to native code and self-optimize at runtime based on low-overhead profiling.) The really nice thing about Dynamo was that it was…
Could such a compiler include the runtime for this in the binary as an option? That might make it a lot more likely to be used by people, because it is all nice and stand-alone. Who would benefit from this most? Is the benefit so diffuse it would almost have to be an open-source project without funding? Or could there be parties that see enough of an advantage to fund this? I guess you could try and get a certain ins…
You could presumably statically link in the runtime. Also, without the dynamically-optimizing runtime, it would run just fine, just a bit slower than normal native code due to the extra indirection. Lots of indirect calls also increase the chances of address mispredictions due to tag collisions in the BTB (Branch Target Buffer).
Function calls/jumps through arrays of pointers are how virtual method calls/optimized virtual method tail calls are executed. Though, in this case, the table offsets would be held in a register instead of immediate values embedded within the instruction. I'm not aware of any instruction set where they've decided it's worthwhile making instructions specifically to speed up C++ virtual member function dispatch, so I doubt they'd find optimizing this worthwhile.
Also, if things go according to plan, your hot path is a long strait run of code, with only occasional jumps through the table.
Re: Theseus: A modern experimental OS written from scratch in Rust
#134Hm, why didn't they join https://www.redox-os.org/ instead?
Well it's an OS written in Rust, they could certainly share things.
Re: Theseus: A modern experimental OS written from scratch in Rust
#135Earlier quoted context omitted.
It's such a silly “thought experiment”. The simple answer is that “identity” is pseudoscience and does not exist; it's a man-made delusion created by the human mind to simplify reality and deal with it more easily. “identity” does not even apply to truly atomic particles, because there is no way to say that they aren't “different” in a next instance of time. There are far too many “thought experiments” and “quæstions…
It's funny that your comment is fading out due to downvotes, as if disappearing from the existence. It reminded me of Douglas Adams' quote from Hitchhiker's Guide to the Galaxy: "There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which stat…
One thing I have found interesting about this concept is lets say I take all the parts and put them back together. Now I have 2 things. Which one is the 'thing'? Clearly both are and are not.
It is a weird quirk of some logic items. They can be both true and false at the same time. Such as things 'this statement is false' which is both true/false at the same time. Is one such example of that. However, sometimes it is clear our test is lacking. With the 'ship' you could say as soon as you switched out anything it was no longer the original thing. What happened to the original thing? Well it went to the same place as when I created it. Which creates its own set of questions.
Re: Theseus: A modern experimental OS written from scratch in Rust
#136I wonder if writing things in Rust just to put that in the headline is becoming a viable strategy for software adoption. There is often very little reason why programming languages matters to end users, but it strongly correlates with visibility in some communities.
Re: Theseus: A modern experimental OS written from scratch in Rust
#137I wonder if writing things in Rust just to put that in the headline is becoming a viable strategy for software adoption. There is often very little reason why programming languages matters to end users, but it strongly correlates with visibility in some communities.
That, and I think it's also fair to acknowledge that language choice can be a serious barrier of entry to contributing to a project or using it in tandem with other technologies. Also if I'm looking to learn from real-world projects I would, personally, prefer to know ahead of time.
"Hi, my project does X, I wrote it in Y," seems a reasonable way to introduce something.
Re: Theseus: A modern experimental OS written from scratch in Rust
#138The name alludes to the Ship of Theseus, a thought experiment where, over the course of many repairs, every piece of a ship is eventually replaced. Given that, I found it interesting that this is applied to a novel greenfield OS effort, instead of a project to rewrite an existing OS in Rust piece-by-piece.
From a comment by raggi below: The goal appears to be to design an architecture that supports in-place updates of most components due to them having tightly constrained state management and inter-component dependencies. Maybe that explains the reference.
Yes, after watching the presentation linked in another comment, it appears the building blocks of Theseus are small code units called "cells", which correspond 1:1 with Rust crates. These can be swapped out because the dynamic loader ensures there are no memory boundary overlaps.
Re: Theseus: A modern experimental OS written from scratch in Rust
#139Re: Theseus: A modern experimental OS written from scratch in Rust
#140Earlier quoted context omitted.
Since you ignored my question, I'll ask it again. > But how is this line germane to the original point again? That somehow being a microkernel means that it can't be a unix like design OS?
Please provide an example of an UNIX descendant from Bell Labs implemented microkernel. POSIX userspace doesn't count, by that measure even an Amiga OS is sundenly an UNIX kernel. Also a reference CS book in UNIX microkernels architecture would be welcomed. Even Tanebaum doesn't call Minix 3 a UNIX, rather UNIX inspired.
Your original post says "UNIX style", not "UNIX descendent from Bell Labs". Don't shift goalposts.