mobile calculi
DESCRIPTION
Mobile Calculi. Prof. Diletta Romana Cacciagrano. Contents. From sequential over concurrent to mobile systems Introduction to the Pi-Calculus Operational Equivalences based on labels Operational Equivalences based on reduction Testing preorders Some e xpressiveness results. - PowerPoint PPT PresentationTRANSCRIPT
Contents From sequential over concurrent to mobile
systems Introduction to the Pi-Calculus Operational Equivalences based on labels Operational Equivalences based on
reduction Testing preorders Some expressiveness results
Mobility in the Pi-Calculus
Name mobility (pi-calculus): Processes communicate via names (channel/links) and names may move (cf. hypertext links, mobile phones, object references,..)
Process mobility: Processes communicate via names and processes may move (cf. mobile code, Jini, higher-order languages, load balancing,..)
The choice of the pure name mobility for the Pi-calculus: furthermore, there is no explicit notion of location and distribution.
• mathematically simpler;• other forms of mobility may (sometimes) be reduced to it;• basis for more complex formalisms.
A calculus of processes whose linkage structure may change (name mobility or dynamic topology)
• rich and well-developed theory• small, yet a high expressive power• a metalanguage for concurrent languages (OO, higher-
order…)• basis for new programming languages• useful type system
But also:
A basic model of computation, where computing is interaction (cf. lambda-calculus, Turing Machines).
Informal Introduction to the Calculus
A small calculus (and the semantics only involves name-for name substitution) but very expressive
• encoding data structures• encoding functions as processes (Milner, Sangiorgi)• encoding synchronous communication with asynchronous
(Honda-Tokoro, Boudol)• encoding polyadic communication with monadic (Quaglia,
Walker)• encoding choice (or not) (Nestmann, Palamidessi)• ....
Informal Introduction to the Calculus