Optimized Lock Assignment and Allocation for Productivity: A Method for Exploiting Concurrency among Critical Sections

One of the major productivity issues in parallel programming arises from the use of lock/unlock operations or atomic/critical sections to enforce mutual exclusion. Not only are these constructs complicated to understand and debug, but they are also often an impediment to achieving scalable parallelism. In this paper, we propose to give the programmer the convenience of critical sections combined with the scalability of fine-grained locks, by solving two technical problems related to optimized assignment of locks to critical sections. The first problem, Minimum Lock Assignment (MLA), addresses the problem of finding the minimum number of locks needed to enforce mutual exclusion among interfering critical sections without any loss of concurrency. The second problem, K-Lock Allocation (K-LA) addresses the problem of allocating a fixed number (K) of locks to critical sections so as to minimize the serialization overhead.