Type Alias Futex 

pub type Futex = Atomic<u32>;

Available on Android, or DragonFly BSD, or FreeBSD, or Fuchsia, or Linux, or OpenBSD, or Emscripten and target feature atomics only.

An atomic for use as a futex that is at least 32-bits but may be larger

Aliased Type

#[repr(C)]
pub struct Futex { /* private fields */ }