 
Summary: Adaptive LongLived Renaming
Using Bounded Memory
(Extended Abstract)
Yehuda Afek \Lambda Hagit Attiya y Arie Fouren z Gideon Stupp x Dan Touitou 
April 12, 1999
Abstract
This paper addresses the properties and design of longlived adaptive algorithms in the read/write
shared memory model. In particular we present adaptive and longlived algorithms that adapt to
the point contention of an operation while using only a bounded amount of memory. We believe
the techniques and building blocks developed here to be of further use in the design of adaptive
and longlived algorithms.
We use the renaming problem as a testcase to demonstrate the new techniques and properties.
Three new implementations of adaptive, waitfree, and longlived renaming in the read/write shared
memory model are presented. Unlike previous algorithms [1] the three algorithms require a bounded
number of registers and adapt to the point contention of an operation. The two previous algorithms
presented in [1] either adapt to the point contention or use a bounded size memory, but not both.
The first algorithm presented here assigns new unique names in the range 1; \Delta \Delta \Delta ; O(k 2 ) to any
process whose initial unique name is taken from a set of size N , for an arbitrary N and where k
is the number of processors that simultaneously take steps or hold a name while the new name
is being acquired. The adaptive step complexity of the first algorithm is O(k 2 log k). The second
