Rendezvous Primitives for Operating System Design

Abstract

A well chosen, comprehensive set of kernel primitives is essential for the construction of higher levels of a computer's operating system. In particular, although many solutions to the classical operating system problems of interprocess synchronization and communication have been proposed in the past, difficulties with destination naming and language construct symmetry have continued to mar most proposed solutions. This thesis proposes a set of primitives, the Rendezvous primitives, that form the kernel of an operating system. It is argued that the Rendezvous primitives constitute a reasonable and practical set of operations on which to base an operating system. The Rendezvous primitive itself is presented as a solution to the interprocess synchronization and communication problems. A rendezvous occurs when two processes synchronize and subsequently exchange messages. Rendezvous is symmetric, in that processes that wish to communicate both use the same primitive; and processes invoke Rendezvous with class designations, not procedure names. Rendezvous is presented within the context of the other primitives, which support the restriction of access to Rendezvous, process creation and destruction, process scheduling, and stack resource management. A comparison of Rendezvous and existing primitives and language constructs to solve interprocess synchronization and communication is made. The full syntax and semantics of the Rendezvous primitives are presented, along with a discussion of their design rationale. The Crossbar Switch, a generalized virtual device interconnection and reconfiguration scheme, is presented as an example of the use to which the Rendezvous primitives might be put. A high level program description of the Crossbar Switch is presented as well. The thesis concludes with a description of the implementation of the Rendezvous kernel on a DEC PDP 11/60. The kernel code is given in an appendix.