Max registers, counters, and monotone circuits

摘要

A method is given for constructing a max register, a linearizable, wait-free concurrent data structure that supports a write operation and a read operation that returns the largest value previously written. For fixed m, an m-valued max register can be constructed from one-bit multi-writer multi-reader registers at a cost of at most [lg m] atomic register operations per write or read. The construction takes the form of a binary search tree: applying classic techniques for building unbalanced search trees gives an unbounded max register with cost O(min(log v, n)) to read or write a value v, where n is the number of processes.