Active objects offer a structured approach to concurrency, encapsulating both unshared state and a thread of control. For efficient data transfer, data should be passed by reference whenever possible, but this introduces aliasing and undermines the validity of the active objects. This paper proposes a minimal variant of ownership types that preserves the required race freedom invariant yet enables data transfer by reference between active objects (that is, without copying) in many cases, and a cheap clone operation where copying is necessary. Our approach is general and should be adaptable to several existing active object systems.

, ,
Lecture Notes in Computer Science
6th Asian Symposium, APLAS 2008
Centrum Wiskunde & Informatica, Amsterdam (CWI), The Netherlands

Clarke, D., Wrigstad, T. (Tobias), Östlund, J. (Johan), & Johnsen, E. B. (2008). Minimal ownership for active objects. In Proceedings of the 6th Asian Symposium, APLAS 2008, Bangalore, India, December 9-11, 2008 (pp. 139–154). doi:10.1007/978-3-540-89330-1_11