On Re-classification and Multithreading

In this paper we consider re-classification in the presence of multi-threading. To this aim we define a multi-threaded extension of the language Fickle, that we call FickleMT. We define an operational semantics and a type and effect system for the language. Each method signature carries the information on the possible effects of the method execution. The type and effect system statically checks this information. The operational semantics uses this information in order to delay the execution of some threads when this could cause access to non-existing members of objects. We show that in the execution of a well-typed expression such delays do not produce deadlock. Lastly we discuss a translation from FickleMT into Java, showing how the operational semantics can be implemented with the standard Java multi-threading constructs.