On the inherent weakness of conditional primitives

Some well-known primitive operations, such as compare-and-swap, can be used, together with read and write, to implement any object in a wait-free manner. However, this paper shows that, for a large class of objects, including counters, queues, stacks, and single-writer snapshots, wait-free implementations using only these primitive operations and a large class of other primitive operations cannot be space efficient: the number of base objects required is at least linear in the number of processes that share the implemented object. The same lower bounds are obtained for implementations of starvation-free mutual exclusion using only primitive operations from this class. For wait-free implementations of a closely related class of onetime objects, lower bounds on the tradeoff between time and space are presented. Keywords Conditionals

• Type: Journal
• Year: 2006
• Where: DC
• Authors: Faith Ellen Fich, Danny Hendler, Nir Shavit
• Keywords: DC 2001, DC 2006, Lower Bounds, Primitive Operations, Well-known Primitive Operations