Algorithms for Concurrency Control In a Dynamic Search Structure
A design of a data structure and efficient algorithms for concurrent
manipulations of a dynamic search structure by independent user processes
Udi Manber and Richard Lander.
Concurrency Control in a Dynamic Search Structure.
ACM Transactions on Database Systems, 9:439-455, 1984.
Additional reading material
Some papers on concurrent access to dynamic search structures.
Analyze the algorithm and implement it.