4 ms·

> And many times the borrow checker is completely inadequate at preventing data races (frequently the case with distributed computing). The borrow checker (in

> And many times the borrow checker is completely inadequate at preventing data races (frequently the case with distributed computing). The borrow checker (in safe rust) always[0] prevents data races. It can't, however, prevent race conditions (but neither can pony do[1]) [0] https://doc.rust-lang.org/nomicon/races.html https://doc.rust-lang.org/nomicon/races.html [1] https://www.ponylang.io/faq/#data-race https://www.ponylang.io/faq/#data-race

throwaway894345 6y ago
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.
- staticassertion 6y ago
  Pony does not prevent race conditions. Two actors can wait forever for the other to send a message, deadlocking.
  - mateo411 6y ago
    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.
    - gpderetta 6y ago
      You can have race conditions with message passing.
      - mateo411 6y ago
        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.
    - spooneybarger 6y ago
      I think this might help: Data race vs race condition: https://blog.regehr.org/archives/490 https://blog.regehr.org/archives/490
      - mateo411 6y ago
        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.
    - stouset 6y ago
      Deadlock is one common symptom of a race condition.
  - throwaway894345 6y ago
    I didn’t say that Pony prevents race conditions. I agree that Pony (nor indeed any language) prevents race conditions.
    - staticassertion 6y ago
      I misread then. Though you did ironically just say that pony does prevent race conditions :P
      - throwaway894345 6y ago
        grrrrr
pjmlp 6y ago
> 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
- throwaway894345 6y ago
  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.

throwaway894345 6y ago

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.

staticassertion 6y ago
Pony does not prevent race conditions. Two actors can wait forever for the other to send a message, deadlocking.
- mateo411 6y ago
  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.
  - gpderetta 6y ago
    You can have race conditions with message passing.
    - mateo411 6y ago
      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.
  - spooneybarger 6y ago
    I think this might help: Data race vs race condition: https://blog.regehr.org/archives/490 https://blog.regehr.org/archives/490
    - mateo411 6y ago
      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.
  - stouset 6y ago
    Deadlock is one common symptom of a race condition.
- throwaway894345 6y ago
  I didn’t say that Pony prevents race conditions. I agree that Pony (nor indeed any language) prevents race conditions.
  - staticassertion 6y ago
    I misread then. Though you did ironically just say that pony does prevent race conditions :P
    - throwaway894345 6y ago
      grrrrr

pjmlp 6y ago

> 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

throwaway894345 6y ago
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.