Lock-Free Data-Structure Iterators

Concurrent data structures are often used with large concurrent software. An iterator that traverses the data structure items is a highly desirable interface that often exists for sequential data structures but is missing from (almost all) concurrent data-structure implementations. In this paper we introduce a technique for adding a linearizable wait-free iterator to a wait-free or a lock-free data structure that implements a set. We use this technique to implement an iterator for the wait-free and lock-free linked-lists and for the lock-free skip-list.