Right, I should have said "race conditions"; it hadn't occurred to me that the two weren't synonymous. My point wasn't that Pony does prevent race conditions, but rather that non-data-race race conditions are much more common in my domain (distributed computing) or really any domain where multiprocess architectures are common so I don't benefit much from the static guarantees that Rust affords.

Pony does not prevent race conditions. Two actors can wait forever for the other to send a message, deadlocking.

I didn’t say that Pony prevents race conditions. I agree that Pony (nor indeed any language) prevents race conditions.

I misread then. Though you did ironically just say that pony does prevent race conditions :P

grrrrr

Is deadlock considered a race condition?

I typically think of a race condition an issue with concurrency where data might be modified by another thread which causes the program to return incorrect results.

I think this might help:

Data race vs race condition:

https://blog.regehr.org/archives/490

That is helpful. I was thinking that a race condition would only include a data race, but this blog defined it broader, so that it would include deadlock.

Deadlock is one common symptom of a race condition.

You can have race conditions with message passing.

Yes, that makes sense.

A race condition happens when data/state is mutated because of the order in which concurrent processes occur. This could happen with threads, message passing, or many other ways.

I think this is distinct from deadlock which occurs when there is at least one circular dependency in the order when different "processes" must perform their operations.

> The borrow checker (in safe rust) always[0] prevents data races.

As long as those data races originate from threads, it cannot prevent data races across processes, for example:

- Modifying the same file location

- Modifying the same table cell without transactions

- Talking to the same IO port

- Data sharing between CPU and GPU

In fairness to the OP, the link they cited defined "data race" explicitly and narrowly as race conditions on memory which I think makes all of your bullets out of scope, but also neuters the original claim pretty considerably.