Generally, Lock and Unlock statements are primitives that should be wholly imple- mented,i.e.,the test of lock state and the operation of locking must be executed continuously without being interrupted. Different from nmormal lock operations, the lock and Unlock algorithm Presented in this paper can be interrupted anywhere by other processes The value of the algorithm in the implementation of concurrent control and mutually-exclusive operations was elucidated with one application of the algorithm in a heterogeneous datedbase united system.
