Function portable_atomic::hint::spin_loop

pub fn spin_loop()

Emits a machine instruction to signal the processor that it is running in a busy-wait spin-loop (“spin lock”).

Upon receiving the spin-loop signal the processor can optimize its behavior by, for example, saving power or switching hyper-threads.

This function is different from thread::yield_now which directly yields to the system’s scheduler, whereas spin_loop does not interact with the operating system.

A common use case for spin_loop is implementing bounded optimistic spinning in a CAS loop in synchronization primitives. To avoid problems like priority inversion, it is strongly recommended that the spin loop is terminated after a finite amount of iterations and an appropriate blocking syscall is made.

Note: On platforms that do not support receiving spin-loop hints this function does not do anything at all.