Events
The Taub Faculty of Computer Science Events and Talks
Eshcar Hilel (M.Sc. Thesis Seminar)
Wednesday, 29.11.2006, 15:00
We present a novel approach for lock-free implementations
of concurrent data structures, based on dynamically maintaining a
coloring of the data structure's items. Roughly speaking,
the data structure's operations are implemented by acquiring
virtual locks on several items of the data structure and then
making the changes atomically; this simplifies the design and
provides clean functionality. The virtual locks are managed with
compare-and-swap or double-compare-and-swap primitives, and helping is
used to guarantee progress; virtual locks are acquired according
to a coloring order that decreases interference and increases concurrency.
Coming back full circle, the legality of the coloring is preserved by
having operations correctly update the colors of the items they modify.
We demonstrate the benefits of the scheme with new nonblocking
implementations of doubly-linked list data structures:
A DCAS-based implementation of a doubly-linked list allowing
insertions and removals anywhere, and CAS-based implementations
in which removals are allowed only at the ends of the list
(insertions can occur anywhere).
In the talk, we will present general background on
concurrent data structures and a summary of the recent work in this field.
We will also discuss questions and open issues we plan to
further explore in the area of lock-based and lock-free algorithms
for concurrent data structures with locality properties.