The Journal of Systems and Softwa(or network), high contention on memory modules and

sp mer orm e 11 con tion ome outdated in dynamic environments like multiprogramming/multiprocessor systems, or (ii) known probability distributions of inputs. This paper presents a new reactive spin-lock algorithm that is completely self-tuning, which means no experimentally tuned parameter interference among processes is inevitable. Many concur-rent processes may cause high traffic on the system bus iation in their environment so as to achieve good perfor-mance in all conditions. reactive spin-lock that can switch from spin-lock using TTSE to a sophisticated local-spin queue-lock when the contention is considered high was suggested in (Lim and Agarwal, 1994; Lim, 1995). However, these reactive spin-locks suffer some draw-backs. First of all, their reactive schemes rely on either q Expanded version of a preliminary result published in the Proceeding