vendor/crossbeam-utils/src/atomic/mod.rs

   1 //! Atomic types.
   2 //!
   3 //! * [`AtomicCell`], a thread-safe mutable memory location.
   4 //! * [`AtomicConsume`], for reading from primitive atomic types with "consume" ordering.
   5
   6 #[cfg(not(crossbeam_loom))]
   7 use cfg_if::cfg_if;
   8
   9 #[cfg(not(crossbeam_loom))]
  10 cfg_if! {
  11     // Use "wide" sequence lock if the pointer width <= 32 for preventing its counter against wrap
  12     // around.
  13     //
  14     // We are ignoring too wide architectures (pointer width >= 256), since such a system will not
  15     // appear in a conceivable future.
  16     //
  17     // In narrow architectures (pointer width <= 16), the counter is still <= 32-bit and may be
  18     // vulnerable to wrap around. But it's mostly okay, since in such a primitive hardware, the
  19     // counter will not be increased that fast.
  20     if #[cfg(any(target_pointer_width = "64", target_pointer_width = "128"))] {
  21         mod seq_lock;
  22     } else {
  23         #[path = "seq_lock_wide.rs"]
  24         mod seq_lock;
  25     }
  26 }
  27
  28 mod atomic_cell;
  29 mod consume;
  30
  31 pub use self::atomic_cell::AtomicCell;
  32 pub use self::consume::AtomicConsume;