Changshu Jian Student Presentation CS 5204 – Operating Systems 1
Outline n n Motivation Formal definition ¨ ¨ ¨ n Application ¨ n Defintion Process Transformation Examples Structural Congruence Reduction Rules Mobile Telephones Summary CS 5204 – Operating Systems 2
Motivation n CS 5204 – Operating Systems 3
Defintion n Name A name refers to a link or a channel ¨ Co-name ¨ Naming a process is not a good elementary notion ¨ n Two basic forms of atomic action ¨ ¨ n Free names fn(P) and bound names bn(P) ¨ ¨ ¨ CS 5204 – Operating Systems 4
Process n Processes are built from names by the following syntax ¨ ¨ ¨ n Prefix Summation Composition Replication Restriction Other control structures ¨ Recursion CS 5204 – Operating Systems 5
Transformation Examples n Process 1 n Process 2 n Process 3 CS 5204 – Operating Systems 6
Structural Congruence n n Processes are identified if they only differ by a change of bound names The Abelian monoid laws for Parallel Commutativity ¨ Associativity ¨ 0 as unit ¨ n The scope extension laws ¨ If , then CS 5204 – Operating Systems 7
Reduction Rules n COMM: n PAR: n RES: n STRUCT: CS 5204 – Operating Systems 8
Mobile telephones CS 5204 – Operating Systems 9
Mobile Telephones n Car n Base n Center n System CS 5204 – Operating Systems 10
Mobile Telephones n CS 5204 – Operating Systems 11