An Object Oriented CAD Project Database

Abstract

Long-lived transaction always causes the bottle neck problem in different design work application domain. CAD VLSI design transactions are typically of long duration with frequently concurrent read-write and read-read accesses. A single design transaction can last for hours, days, even months before it completes. So a long duration transaction will cause long duration locks; we will have long blocking when we use a common concurrency control algorithm. Based on this analysis, we proposed a distributed and open control mechanism with multilevel transaction manager can be effectively used to drive the design process while not restricting how the designer interacts with the tools. As the design process becomes more automated, the designer spends less time directly manipulating the design data and more time managing CAD tools that manipulate the design data. Overall, design data manipulation shifts more towards the CAD tools and away from direct designer intervention.