Use Ordering::Acquire in Arc::try_unwrap #150709
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After unwrapping the Arc, the reader should observe all writes that occurred before the penultimate refcount was dropped. Note that this is consistent with the ordering used in `Arc::is_unique` and `Arc::make_mut`, both of which have similar function.
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| // of the penultimate `Arc`, allowing the resulting value to contain | ||
| // all modifications that may have happened due to that copy of the | ||
| // `Arc`. | ||
| if this.inner().strong.compare_exchange(1, 0, Acquire, Relaxed).is_err() { |
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Did you perhaps missed the fact that the success path already contains acquire fence?
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After unwrapping the Arc, the reader should observe all writes that occurred before the penultimate refcount was dropped. Note that this is consistent with the ordering used in
Arc::is_uniqueandArc::make_mut, both of which have similar function.See also discussion on #150631 (comment)
r? @Mark-Simulacrum