ABSTRACT

Persistence can be easily implemented in the actor concurrent language Plasmall for three reasons. On one hand, each actor is selfcontained, i.e. its value is a PlasmaĻI feature merging actor description and actor environment; this value is called "closure". On the other hand, in Plasmall the user can access and handle all the internal forms of the interpreter. Moreover, the information migration between two sites (necessary because an application processes on multiple sites) has been solved, taking into account the problem of recursive environments. So we can inductively access by the concept of closure to all the actors which participate to the activity of an actor and write them in a file medium. Persistence of an actor system is implemented by two new primitives, putcode which saves the whole or partial application state in a file under a coded form and getcode which reads this stored coded state and restores it during a current session