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

   1 #![warn(clippy::invalid_atomic_ordering)]
   2
   3 use std::sync::atomic::{AtomicPtr, Ordering};
   4
   5 fn main() {
   6     let ptr = &mut 5;
   7     let ptr2 = &mut 10;
   8     // `compare_exchange_weak` testing
   9     let x = AtomicPtr::new(ptr);
  10
  11     // Allowed ordering combos
  12     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::Relaxed);
  13     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Acquire, Ordering::Acquire);
  14     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Acquire, Ordering::Relaxed);
  15     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Release, Ordering::Relaxed);
  16     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::AcqRel, Ordering::Acquire);
  17     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::AcqRel, Ordering::Relaxed);
  18     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::SeqCst, Ordering::Relaxed);
  19     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::SeqCst, Ordering::Acquire);
  20     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::SeqCst, Ordering::SeqCst);
  21
  22     // AcqRel is always forbidden as a failure ordering
  23     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Relaxed, Ordering::AcqRel);
  24     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Acquire, Ordering::AcqRel);
  25     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Release, Ordering::AcqRel);
  26     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::AcqRel, Ordering::AcqRel);
  27     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::SeqCst, Ordering::AcqRel);
  28
  29     // Release is always forbidden as a failure ordering
  30     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::Release);
  31     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Acquire, Ordering::Release);
  32     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Release, Ordering::Release);
  33     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::AcqRel, Ordering::Release);
  34     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::SeqCst, Ordering::Release);
  35
  36     // Release success order forbids failure order of Acquire or SeqCst
  37     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Release, Ordering::Acquire);
  38     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Release, Ordering::SeqCst);
  39
  40     // Relaxed success order also forbids failure order of Acquire or SeqCst
  41     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::SeqCst);
  42     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::Acquire);
  43
  44     // Acquire/AcqRel forbids failure order of SeqCst
  45     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Acquire, Ordering::SeqCst);
  46     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::AcqRel, Ordering::SeqCst);
  47 }