fix(thread_aware): Move source registration up so we prevent race condition#404
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Darksecond wants to merge 1 commit intomainfrom
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fix(thread_aware): Move source registration up so we prevent race condition#404Darksecond wants to merge 1 commit intomainfrom
Darksecond wants to merge 1 commit intomainfrom
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Pull request overview
This PR adjusts thread_aware::cell::Arc::relocated to register the source slot earlier so that relocations where the source and destination resolve to the same storage slot don’t trigger repeated factory execution, and adds a regression test covering that scenario.
Changes:
- Pre-populate the source storage slot (when pinned and currently empty) before checking/creating the destination value in
Arc::relocated. - Remove the previous “restore source slot after destination creation” logic.
- Add a unit test asserting the factory runs only once when relocating with
source == destination.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.
| File | Description |
|---|---|
| crates/thread_aware/src/cell/mod.rs | Moves/changes source-slot registration logic inside Arc::relocated, impacting same-slot relocation behavior. |
| crates/thread_aware/src/cell/tests.rs | Adds a regression test for factory invocation count when source == destination. |
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| if let MemoryAffinity::Pinned(source) = source { | ||
| if guard.get_clone(source).is_none() { | ||
| guard.replace(source, sync::Arc::clone(&self.value)); | ||
| } | ||
| } |
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| if guard.get_clone(source).is_none() { | ||
| guard.replace(source, sync::Arc::clone(&self.value)); | ||
| } | ||
| } |
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| #[test] | ||
| fn factory_runs_once_per_affinity_when_source_eq_destination() { | ||
| use std::sync::atomic::{AtomicUsize, Ordering}; | ||
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| static CALLS: AtomicUsize = AtomicUsize::new(0); | ||
| let arc = PerCore::new(|| { | ||
| CALLS.fetch_add(1, Ordering::Relaxed); | ||
| 0u32 | ||
| }); | ||
| assert_eq!(CALLS.load(Ordering::Relaxed), 1); | ||
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| let here = pinned_affinities(&[1])[0]; | ||
| let _ = arc.clone().relocated(here.into(), here); | ||
| let _ = arc.clone().relocated(here.into(), here); | ||
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| // Without the fix this is 3 (factory re-runs each time source slot is empty | ||
| // at destination-lookup time). | ||
| assert_eq!(CALLS.load(Ordering::Relaxed), 1); |
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This prevents a race condition when source equals destination.