Abstract: Apparatus and method for controlling concurrent process access of infrastructures comprising tree structures of complex object nodes. Apparatus associated with each complex object node records an accumulate count of each type of lock applied by concurrently running computer processes against each infrastructure complex node. The apparatus and method respond to lock application and removal requests of concurrently running computer processes for incrementing and decrementing an accumulative count of locks currently pending against a process selected complex node and accumulative counts of locks currently pending against ancestral complex nodes located in a tree structure of the process selected complex node to maintain a current record of selective locks applied to each infrastructure complex node thereby enabling read and write of information into and from complex nodes of the infrastructure.