New PNtalk architecture proposal - PNtalk 2000

The proposed PNtalk 2000 is intended for distributed systems prototyping. Basic features (proposal):

• Language = PNtalk 98 (latest version of the PNtalk language) + sequential methods (a sequential method is defined as a (single) transition action instead of a whole Petri net).
• Distributed PNtalk engine allowing for migration of objects.
• Client-server architecture: server(s) = (distributed) PNtalk engine (in Prolog, Smalltalk, C++) + source code repository + compiler, clients = shell (command language), GUIs (applet, Smalltalk), arbitrary applications.
• Possibility to restore saved state and replay recorded history of a subsystem.
• Incremental OOPN compilation, interactive system state inspection and incremental modification.
• Support for analysis and verification of OOPNs.
• Reflective capabilities (including creation of nets, incremental compilation, simulation, incremental modification of a system state, analysis).
• Interoperability: Smalltalk, Prolog, C++, CORBA.
• Multiuser system (each PNtalk process has its owner and runs in virtual PNtalk machine; multiple users can be connected to it - it is a kind of operating system).
• Each process (or subsystem) runs in either real or simulation time. Multiple concurrent simulations are allowed in one PNtalk engine.

The PNtalk 2000 architecture details will be published soon. Its prototype will be implemented during next two years.

This work is supported by grant GACR No. 102/00/1017 "Modeling, verification, and prototyping of distributed systems by means of Petri nets" (Prof. RNDr. Milan Ceska, CSc.)

Some aspects of current state of the PNtalk2000 development is reflected by several working documents (mostly in czech language).