pub fn spin_loop()
Signals the processor that it is entering a busy-wait spin-loop.
Upon receiving spin-loop signal the processor can optimize its behavior by, for example, saving power or switching hyper-threads.
This function is different than
std::thread::yield_now which directly yields to the system's scheduler, whereas
spin_loop only signals the processor that it is entering a busy-wait spin-loop without yielding control to the system's scheduler.
Using a busy-wait spin-loop with
spin_loop is ideally used in situations where a contended lock is held by another thread executed on a different CPU and where the waiting times are relatively small. Because entering busy-wait spin-loop does not trigger the system's scheduler, no overhead for switching threads occurs. However, if the thread holding the contended lock is running on the same CPU, the spin-loop is likely to occupy an entire CPU slice before switching to the thread that holds the lock. If the contending lock is held by a thread on the same CPU or if the waiting times for acquiring the lock are longer, it is often better to use
Note: On platforms that do not support receiving spin-loop hints this function does not do anything at all.
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Licensed under the Apache License, Version 2.0 or the MIT license, at your option.