Mach is a multiprocessor operating system being implemented at Carnegie-Mellon University. An important component of the Mach design is the use of memory objects which can be managed either by the kernel or by user programs through a message interface. This feature allows applications such as transaction management systems to participate in decisions regarding secondary storage management and page replacement.

Facilities that support distributed transactions on user-defined types can be implemented efficiently and can simplify the construction of reliable distributed programs.To demonstrate these points, this paper describes a prototype transaction facility, called TABS, that supports objects, transparent communication, synchronization, recovery, and transaction management.Various objects that use the facilities of TABS are exemplified and the performance of the system is discussed in detail.The paper concludes that the prototype provides useful facilities, and that it would be feasible to build a high performance implementation based on its ideas.

The TABS prototype is an experimental facility that provides operating system-level support for distributed transactions that operate on shared abstract types. The facility is designed to simplify the construction of highly available and reliable distributed applications. This paper describes the TABS system model, the TABS prototype's structure, and certain aspects of its operation. The paper concludes with a discussion of the status of the project and a preliminary evaluation.