Adding Context and Static Groups into PVMJ

This paper describes how the concept of a communication context can be added to the PVM system. Context is a way to partition the communication space so that a message sent within one context cannot be received in a diierent context. This partitioning is essential for the design of robust parallel software libraries. Context can be added to PVM in such a way that existing PVM applications need not be changed. A potential bottleneck of communication, especially for massively parallel computers , is PVM's central group server. This paper also describes a method for adding static groups to PVM. Allowing a user to specify a group with a static membership list eliminates the central bottleneck for many collective operations. The static group functions proposed here incorporate context to provide safe, collective operations.