src/tools/clippy/tests/ui/atomic_ordering_fetch_update.rs

   1 #![warn(clippy::invalid_atomic_ordering)]
   2
   3 use std::sync::atomic::{AtomicIsize, Ordering};
   4
   5 fn main() {
   6     // `fetch_update` testing
   7     let x = AtomicIsize::new(0);
   8
   9     // Allowed ordering combos
  10     let _ = x.fetch_update(Ordering::Relaxed, Ordering::Relaxed, |old| Some(old + 1));
  11     let _ = x.fetch_update(Ordering::Acquire, Ordering::Acquire, |old| Some(old + 1));
  12     let _ = x.fetch_update(Ordering::Acquire, Ordering::Relaxed, |old| Some(old + 1));
  13     let _ = x.fetch_update(Ordering::Release, Ordering::Relaxed, |old| Some(old + 1));
  14     let _ = x.fetch_update(Ordering::AcqRel, Ordering::Acquire, |old| Some(old + 1));
  15     let _ = x.fetch_update(Ordering::AcqRel, Ordering::Relaxed, |old| Some(old + 1));
  16     let _ = x.fetch_update(Ordering::SeqCst, Ordering::Relaxed, |old| Some(old + 1));
  17     let _ = x.fetch_update(Ordering::SeqCst, Ordering::Acquire, |old| Some(old + 1));
  18     let _ = x.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |old| Some(old + 1));
  19
  20     // AcqRel is always forbidden as a failure ordering
  21     let _ = x.fetch_update(Ordering::Relaxed, Ordering::AcqRel, |old| Some(old + 1));
  22     let _ = x.fetch_update(Ordering::Acquire, Ordering::AcqRel, |old| Some(old + 1));
  23     let _ = x.fetch_update(Ordering::Release, Ordering::AcqRel, |old| Some(old + 1));
  24     let _ = x.fetch_update(Ordering::AcqRel, Ordering::AcqRel, |old| Some(old + 1));
  25     let _ = x.fetch_update(Ordering::SeqCst, Ordering::AcqRel, |old| Some(old + 1));
  26
  27     // Release is always forbidden as a failure ordering
  28     let _ = x.fetch_update(Ordering::Relaxed, Ordering::Release, |old| Some(old + 1));
  29     let _ = x.fetch_update(Ordering::Acquire, Ordering::Release, |old| Some(old + 1));
  30     let _ = x.fetch_update(Ordering::Release, Ordering::Release, |old| Some(old + 1));
  31     let _ = x.fetch_update(Ordering::AcqRel, Ordering::Release, |old| Some(old + 1));
  32     let _ = x.fetch_update(Ordering::SeqCst, Ordering::Release, |old| Some(old + 1));
  33
  34     // Release success order forbids failure order of Acquire or SeqCst
  35     let _ = x.fetch_update(Ordering::Release, Ordering::Acquire, |old| Some(old + 1));
  36     let _ = x.fetch_update(Ordering::Release, Ordering::SeqCst, |old| Some(old + 1));
  37
  38     // Relaxed success order also forbids failure order of Acquire or SeqCst
  39     let _ = x.fetch_update(Ordering::Relaxed, Ordering::SeqCst, |old| Some(old + 1));
  40     let _ = x.fetch_update(Ordering::Relaxed, Ordering::Acquire, |old| Some(old + 1));
  41
  42     // Acquire/AcqRel forbids failure order of SeqCst
  43     let _ = x.fetch_update(Ordering::Acquire, Ordering::SeqCst, |old| Some(old + 1));
  44     let _ = x.fetch_update(Ordering::AcqRel, Ordering::SeqCst, |old| Some(old + 1));
  45 }