Computing system with exception handler and method of handling exceptions in a computing system

US5909574A · kind A · utility

Assignee

• Nortel Networks Limited · CA

Inventor

• Peter Meyer · Beverungen, DE

Key dates

• Filing date: Dec 23, 1997
• Grant date: Jun 1, 1999
• Expiry date: Dec 23, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F9/3863
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A computing system in which permanent state changes to portions of the system are effected using transactions, including an exception handier and a method of handling exceptions in such a system is disclosed. Specifically, the computing system comprises a processor for executing at least one process; and scratchpad memory. A transactional subsystem is interconnected with the processor and has a plurality of states. State changes to the transactional subsystem are made irreversible only upon successful completion of a transaction. Program memory interconnected with the processor contains an exception handler for handling an exception dependent on one of a transaction. The handler adapts the processor to buffer data resulting from the exception in the scratchpad memory; and upon successful completion of the transaction, transfer the buffered data to an exception buffer accessible by a software process executing on the processor. Upon unsuccessful completion of the transaction, the buffered data in the scratchpad memory is discarded. Preferably, the transactional subsystem is a shared memory system.