Differences between lock spin and mutex usage scenarios

Under a single-core CPU, spin lock is meaningless and will only affect the normal thread response; although using mutex will switch between the two queues of "suspend" and "running", it improves the overall response ratio of the system.

Under multi-core CPU, the polling time of spin lock on multiple and cores is negligible. Using spin lock avoids time consumption caused by queue switching.

The practice of modern operating systems, in a multi-core environment, when implementing mutex, if the lock operation is performed, the polling (spin lock) is performed. After this period of time, the traditional mutex is used to block (join pendingqueue).If the program is predictably blocked for a short time, spin lock can be actively used.