The current version of the persistent storage is a single-threaded and single-processor system. If the system is used for a client-server database system, multiple requests are sent to the server, but a single-threaded system cannot handle such requests at the same time. The requests will be sequentially processed one by one and even a simple request may be responded after a lengthy interval.
A multi-threaded and/or multi-processor system is desirable for such operations. For the implementation of such complex system, discrete locking mechanisms with the help of the clarified atomicity are needed.
The read-only-grabbing mechanism is designed for such concurrent/ parallel operations.