Class that models Mutex Concept using a spin lock.
A spin_mutex models the Mutex Concept. A spin_mutex is not scalable, fair, or recursive. It is ideal when the lock is lightly contended and is held for only a few machine instructions. If a thread has to wait to acquire a spin_mutex, it busy waits, which can degrade system performance if the wait is long. However, if the wait is typically short, a spin_mutex significantly improve performance compared to other mutexes.
See Mutex Concept.