Richard P. Draves

Using continuations to implement thread management and communication in operating systems

We have improved the performance of the Mach 3.0 operating system by redesigning its internal thread and interprocess communication facilities to use continuations as the basis for control transfer. Compared to previous versions of Mach 3.0, our new system consumes 85% less space per thread. Cross-address space remote procedure calls execute 14% faster. Exception handling runs over 60% faster.In addition to improving system performance, we have used continuations to generalize many control transfer optimizations that are common to operating systems, and have recast those optimizations in terms of a single implementation methodology. This paper describes our experiences with using continuations in the Mach operating system.

High Performance Distributed Transaction Processing in a General Purpose Computing Environment

This paper argues that transaction processing adds relatively little overhead to applications that access shared abstract data objects. It also argues that transaction processing can be made easy to use for both users and implementors of shared objects. The implication is that transaction processing can be a very useful technique in a variety of application domains. To provide more evidence as to the utility of transaction systems, the paper briefly describes the Camelot Distributed Transaction Facility, which has been developed at Carnegie Mellon University. Camelot executes on a variety of uni- and multi-processors on top of the Unix-compatible, Mach operating system. The paper also describes Camelots interfaces and contains preliminary performance information gathered on pre-alpha release versions of Camelot.