Open AccessAliasing Models for Mobile Objects
Author(s) -
Uwe Nestmann,
Hans Hüttel,
Josva Kleist,
Massimo Merro
Publication year - 1999
Publication title -
brics report series
Language(s) - English
Resource type - Journals
eISSN - 1601-5355
pISSN - 0909-0878
DOI - 10.7146/brics.v6i44.20114
Subject(s) - aliasing , computer science , programming language , alias , object (grammar) , class (philosophy) , semantics (computer science) , programmer , abstraction , theoretical computer science , operational semantics , distributed object , state (computer science) , common object request broker architecture , artificial intelligence , data mining , philosophy , epistemology , undersampling
In Obliq, a lexically scoped, distributed, object-oriented programming language, object migration was suggested as the creation of a copy of an object's state at the target site, followed by turning the object itself into an alias, also called surrogate, for the remote copy. We consider the creation of object surrogates as an abstraction of the above-mentioned style of migration. We introduce Øjeblik, a typed distribution-free subset of Obliq, and provide four different configuration-style semantics, which only differ in the respective aliasing model. We show that two of the semantics, one of which matches Obliq's implementation, render migration unsafe, while our new proposal allows for safe migration at least for a large class of program contexts. In addition, we propose a type system that allows a programmer to statically guarantee that programs belong to that class. Our work suggests a straightforward repair of Obliq's aliasing model.