Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

clarify Arc::clone overflow check comment #98364

Merged
merged 1 commit into from Jun 24, 2022
Merged

Conversation

RalfJung
Copy link
Member

I had to read this twice to realize that this is explaining that the code is technically unsound, so move that into a dedicated paragraph and make the wording a bit more explicit.

@rust-highfive
Copy link
Collaborator

Hey! It looks like you've submitted a new PR for the library teams!

If this PR contains changes to any rust-lang/rust public library APIs then please comment with @rustbot label +T-libs-api -T-libs to tag it appropriately. If this PR contains changes to any unstable APIs please edit the PR description to add a link to the relevant API Change Proposal or create one if you haven't already. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary.

Examples of T-libs-api changes:

  • Stabilizing library features
  • Introducing insta-stable changes such as new implementations of existing stable traits on existing stable types
  • Introducing new or changing existing unstable library APIs (excluding permanently unstable features / features without a tracking issue)
  • Changing public documentation in ways that create new stability guarantees
  • Changing observable runtime behavior of library APIs

@rustbot rustbot added the T-libs Relevant to the library team, which will review and decide on the PR/issue. label Jun 22, 2022
@rust-highfive
Copy link
Collaborator

r? @Mark-Simulacrum

(rust-highfive has picked a reviewer for you, use r? to override)

@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jun 22, 2022
// any realistic program.
//
// This check is not 100% water-proof: we error when the refcount grows beyond `isize::MAX`
// on the assumption that there aren't ~2 billion threads incrementing the reference count
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Maybe worth noting where the 2 billion comes from? On a 16-bit platform for example this is much more of a problem (not that we support those today, I think?).

Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

So no test that triggers this logic on 64 bit pointer systems ? :)
This logic Is more a bout detecting corrupted memory.
Could this functionality be configurable ?. So can get smaller code size, and 1 less branch.

@Mark-Simulacrum
Copy link
Member

r=me with or without nit fixed

@Mark-Simulacrum Mark-Simulacrum added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jun 22, 2022
@RalfJung
Copy link
Member Author

I did some more rewording to avoid the issue you pointed out; please take another look.

@Mark-Simulacrum
Copy link
Member

@bors r+ rollup

@bors
Copy link
Contributor

bors commented Jun 22, 2022

📌 Commit 46b2454 has been approved by Mark-Simulacrum

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Jun 22, 2022
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this pull request Jun 23, 2022
clarify Arc::clone overflow check comment

I had to read this twice to realize that this is explaining that the code is technically unsound, so move that into a dedicated paragraph and make the wording a bit more explicit.
compiler-errors added a commit to compiler-errors/rust that referenced this pull request Jun 23, 2022
clarify Arc::clone overflow check comment

I had to read this twice to realize that this is explaining that the code is technically unsound, so move that into a dedicated paragraph and make the wording a bit more explicit.
bors added a commit to rust-lang-ci/rust that referenced this pull request Jun 24, 2022
…piler-errors

Rollup of 16 pull requests

Successful merges:

 - rust-lang#96173 (Fix documentation for  `with_capacity` and `reserve` families of methods)
 - rust-lang#98184 (Give name if anonymous region appears in impl signature)
 - rust-lang#98259 (Greatly improve error reporting for futures and generators in `note_obligation_cause_code`)
 - rust-lang#98269 (Provide a `PathSegment.res` in more cases)
 - rust-lang#98283 (Point at private fields in struct literal)
 - rust-lang#98305 (prohibit_generics: don't alloc error string if no error emitted)
 - rust-lang#98310 (rustdoc: optimize loading of source sidebar)
 - rust-lang#98353 (Migrate two diagnostics from the `rustc_builtin_macros` crate)
 - rust-lang#98355 (Update no_default_libraries handling for emscripten target)
 - rust-lang#98364 (clarify Arc::clone overflow check comment)
 - rust-lang#98365 (Address review comments from rust-lang#98259)
 - rust-lang#98388 (implement `iter_projections` function on `PlaceRef`)
 - rust-lang#98390 (Fixes handling of keywords in rustdoc json output)
 - rust-lang#98409 (triagebot.toml: Allow applying nominated labels)
 - rust-lang#98410 (Update books)
 - rust-lang#98422 (Update browser-ui-test version to 0.9.6)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit e749ba2 into rust-lang:master Jun 24, 2022
@rustbot rustbot added this to the 1.63.0 milestone Jun 24, 2022
@RalfJung RalfJung deleted the arc-clone branch June 25, 2022 12:51
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. T-libs Relevant to the library team, which will review and decide on the PR/issue.
Projects
None yet
Development

Successfully merging this pull request may close these issues.

None yet

6 participants