Module priomutex::spin_one

A high-performance variant of priomutex.

This mutex is very similar to the one in the root of the crate, except that the next-in-line thread busy-waits. This means that dropping the MutexGuard never requires any syscalls, and takes 100-200ns on my machine (20x faster than the standard priomutex). No matter how many threads are waiting on your mutex, it's guaranteed that only one will be busy-waiting at any time.

Suppose thread 1 has the lock and thread 2 is busy-waiting for it. Now thread 3 tries to lock the mutex with a higher priority then thread 2. Thread 3 will now busy-wait, while thread 2 goes to sleep. When thread 1 releases the lock, thread 3's lock call will return, while thread 2 wakes up and starts busy-waiting once more.

Structs

Mutex	A mutex which allows waiting threads to specify a priority.
MutexGuard	An RAII guard. Frees the mutex when dropped.