Neither is used in practice since they perform well only at exceptionally high loads. Unfortunately, the funnels are linearizable but blocking, and the elimination trees are non-blocking but not linearizable. %X The literature describes two high performance concurrent stack algorithms based on combining funnels and elimination trees.

%K Array Collections Concurrent Elimination LockFree Scalable Stack %B Proceedings of the sixteenth annual ACM symposium on Parallelism in algorithms and architectures We believe its simplicity and scalability make it a viable practical alternative to existing constructions for implementing concurrent stacks. As our empirical results show, the resulting elimination-backoff stack performs as well as the simple stack at low loads, and increasingly outperforms all other methods (lock-based and non-blocking) as concurrency increases. It is based on the following simple observation: that a single elimination array used as a backoff scheme for a simple lock-free stack is lock-free, linearizable, and scalable. The question of designing a stack algorithm that is non-blocking, linearizable, and scales well throughout the concurrency range, has thus remained open.This paper presents such a concurrent stack algorithm. The literature also describes a simple lock-free linearizable stack algorithm that works at low loads but does not scale as the load increases.

The literature describes two high performance concurrent stack algorithms based on combining funnels and elimination trees.

Freestack