Fix a dangling reference in rustc_thread_pool#146799
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| // SAFETY: Once we call `set` on the internal `latch`, | ||
| // the target may proceed and invalidate `this`! | ||
| match unsafe { &(*this).kind } { |
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A safety comment here should explain why it is safe to create a reference out of (*this).kind. That it does not seem to do that, may be the reason it is a NOTE.
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Well, we added the NOTE in rayon before there was much consensus on proper SAFETY comments. It's definitely a safety-relevant comment, even if it's not directly justifying this unsafe.
(Personally, I would have used a single unsafe block around all of this, but this was also added after the port from rayon. Originally, it's still using the unsafe fn context for inner unsafe too.)
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Thanks for the review -- I added another SAFETY comment as requested. @bors r=lcnr |
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Fix a dangling reference in `rustc_thread_pool` This diverged from `rayon` in rust-lang#142384, where a cleanup commit turned the matched `worker_index` into a reference, which is read _after_ the `set` that may kill it. I've moved that read beforehand, and I hope the new comments will emphasize the subtlety of this unsafe code. Hopefully fixes rust-lang#146677.
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Rollup of 13 pull requests Successful merges: - #146632 (Fix uses of "adaptor") - #146731 (test: Use SVG for terminal url test) - #146775 (fixes for numerous clippy warnings) - #146784 ([win] Use find-msvc-tools instead of cc to find the linker and rc on Windows) - #146799 (Fix a dangling reference in `rustc_thread_pool`) - #146802 (mbe: Simplifications and refactoring) - #146806 (add private module override re-export test) - #146827 (Linker-plugin-based LTO: update list of good combinations (inc. beta + nightly)) - #146875 (tests/run-make/crate-loading: Rename source files for clarity) - #146896 (rustc-dev-guide subtree update) - #146898 (Update books) - #146899 (Fix a crash/mislex when more than one frontmatter closing possibility is considered) - #146907 (add regression test for issue 146537) r? `@ghost` `@rustbot` modify labels: rollup
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Rollup of 10 pull requests Successful merges: - #146632 (Fix uses of "adaptor") - #146731 (test: Use SVG for terminal url test) - #146775 (fixes for numerous clippy warnings) - #146784 ([win] Use find-msvc-tools instead of cc to find the linker and rc on Windows) - #146799 (Fix a dangling reference in `rustc_thread_pool`) - #146802 (mbe: Simplifications and refactoring) - #146806 (add private module override re-export test) - #146827 (Linker-plugin-based LTO: update list of good combinations (inc. beta + nightly)) - #146875 (tests/run-make/crate-loading: Rename source files for clarity) - #146877 (prevent line number from being copied in chrome) r? `@ghost` `@rustbot` modify labels: rollup
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Rollup merge of #146799 - cuviper:dangling-count-latch, r=lcnr Fix a dangling reference in `rustc_thread_pool` This diverged from `rayon` in #142384, where a cleanup commit turned the matched `worker_index` into a reference, which is read _after_ the `set` that may kill it. I've moved that read beforehand, and I hope the new comments will emphasize the subtlety of this unsafe code. Hopefully fixes #146677.
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Fix a dangling reference in `rustc_thread_pool` This diverged from `rayon` in rust-lang#142384, where a cleanup commit turned the matched `worker_index` into a reference, which is read _after_ the `set` that may kill it. I've moved that read beforehand, and I hope the new comments will emphasize the subtlety of this unsafe code. Hopefully fixes rust-lang#146677.
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…iaskrgr Rollup of 10 pull requests Successful merges: - rust-lang#146632 (Fix uses of "adaptor") - rust-lang#146731 (test: Use SVG for terminal url test) - rust-lang#146775 (fixes for numerous clippy warnings) - rust-lang#146784 ([win] Use find-msvc-tools instead of cc to find the linker and rc on Windows) - rust-lang#146799 (Fix a dangling reference in `rustc_thread_pool`) - rust-lang#146802 (mbe: Simplifications and refactoring) - rust-lang#146806 (add private module override re-export test) - rust-lang#146827 (Linker-plugin-based LTO: update list of good combinations (inc. beta + nightly)) - rust-lang#146875 (tests/run-make/crate-loading: Rename source files for clarity) - rust-lang#146877 (prevent line number from being copied in chrome) r? `@ghost` `@rustbot` modify labels: rollup
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This diverged from
rayonin #142384, where a cleanup commit turned the matchedworker_indexinto a reference, which is read after thesetthat may kill it. I've moved that read beforehand, and I hope the new comments will emphasize the subtlety of this unsafe code.Hopefully fixes #146677.