A Source-to-Source Transformerfor QD-locking

Abstract: Locking is a common method of synchronization in parallel programming. Delegation locking is a form of locking where in threads may, under the right circumstances,delegate critical sections to be executed by another thread instead of waiting for the lock. Queue Delegation Locking (QD-locking) is a novel method of delegation locking which drastically improves performance in situations where one or more locks are moderately or heavily contented, and essentially lets a thread delegate a critical section to the thread which currently holds the lock. QD-locking requires critical sections to be written differently than standard phreads mutex locking. In this thesis, we discuss the feasibility of taking a program which uses pthreads mutex locks and automatically transforming it into a program using QD-locking. We describe an implementation of this transformation, called QDTrans, using the qd_lock_lib implementation of QD-locking in the C programming language.We also discuss the quality and performance of code tranformed by QDTrans.QDTrans is currently capable of successfully converting seven out of the nineSPLASH2 benchmarks.