diff options
Diffstat (limited to 'src/tools/clippy/src/docs/missing_spin_loop.txt')
-rw-r--r-- | src/tools/clippy/src/docs/missing_spin_loop.txt | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/src/tools/clippy/src/docs/missing_spin_loop.txt b/src/tools/clippy/src/docs/missing_spin_loop.txt new file mode 100644 index 000000000..3a06a91d7 --- /dev/null +++ b/src/tools/clippy/src/docs/missing_spin_loop.txt @@ -0,0 +1,27 @@ +### What it does +Check for empty spin loops + +### Why is this bad? +The loop body should have something like `thread::park()` or at least +`std::hint::spin_loop()` to avoid needlessly burning cycles and conserve +energy. Perhaps even better use an actual lock, if possible. + +### Known problems +This lint doesn't currently trigger on `while let` or +`loop { match .. { .. } }` loops, which would be considered idiomatic in +combination with e.g. `AtomicBool::compare_exchange_weak`. + +### Example + +``` +use core::sync::atomic::{AtomicBool, Ordering}; +let b = AtomicBool::new(true); +// give a ref to `b` to another thread,wait for it to become false +while b.load(Ordering::Acquire) {}; +``` +Use instead: +``` +while b.load(Ordering::Acquire) { + std::hint::spin_loop() +} +```
\ No newline at end of file |