Max registers, counters, and monotone circuits

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 multireader 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. It is also shown how a max register can be used to transform any monotone circuit into a wait-free concurrent data structure that provides write operations setting the inputs to the circuit and a read operation that returns the value of the circuit on the largest input values previously supplied. The cost of a write is bounded by O(Sd min( lg m , n), where m is the si...

• Type: Conference
• Year: 2009
• Where: PODC
• Authors: James Aspnes, Hagit Attiya, Keren Censor
• Keywords: M-valued Max Register, Max Register, Parallel Computing, PODC 2009, Unbounded Max Register