Consistency Management in the EROS Kernel Implementing Efficient Orthogonal Persistence in A Pure Capability System

EROS is a persistent operating system targeted towards managing resources with great longevity. The system provides a persistent single-level store supporting two fundamental object types: nodes and pages. All primary objects, including memory segments and protection domains, are constructed out of these fundamental objects, and inherit their persistence. EROS is a pure capability system; access to objects is provided exclusively through the invocation of kernel-enforced, secure capabilities. This paper describes the EROS Abstract Machine and the mechanisms used to achieve efficient consistency management within the system. The implementation, including all primary objects, a low overhead checkpoint/migration subsystem, and an efficient interprocess communication mechanism, requires less than 64 Kbytes of supervisor code (prior to size tuning). This work was supported by the Hewlett-Packard Research Grants Program, the AT&T Foundation, CNRI as manager for NSF and ARPA under cooperative agreement #NCR-8919038, NSF #CDA-92-14924, and ARPA #MDA972-95-1-0013. Copyright c 1996, Jonathan S. Shapiro. Permission is granted to redistribute this document in electronic or paper form, provided that this copyright notice is retained.