Concurrency Control Mechanism Based On User-Level Lock For Business Objects

Based on the known technologies of MMDB and DRDB, this thesis studies the concurrency control mechanism for business objects in application servers of critical business. To better achieve the high-performance, one concurrency control mechanism on the basis of user-level lock is presented, the methods to implement user-level lock is explored, a implementation for user-level spinlock and multi-granularity lock are described. On the strategy for lock management, we physically attaches the locks to the locked business object itself, thereby making the locks directly accessible, rather than indirectly accessible via a hash lock-table structure. Furthermore, this thesis adopts a transaction autonomous locking strategy. In autonomous locking, transactions acquire and release locks via operations on shared memory , in contrast to traditional DBMS locking where communication with a lock manager is involved, thus the concurrency degree of system has been increased. Finally, some weakness and problems which should be further studied in current research are proposed.