The implementation of software fault tolerance in the Intel 80286 processor

How the architecture of the Intel 80286 microprocessor can be used to implement fault-tolerant software structures is analyzed. An approach presented by M. Anco et al. (1987), the recovery metaprogram, is supported by software layers which use the privilege levels in the 80286. A recovery metaprogram is a software component that concentrates all the actions needed for fault tolerance and recovery. The implementation of a conversation, which is an extension of the concept of a recovery block to cooperating concurrent processes, is covered. While the details are specific to the 80286 architecture, the general results apply to any architecture with three or more rings of privilege and a segmented virtual memory using descriptors