A Class Hierarchy Emulating Virtual Shared Objects on Message-Passing Systems

Multicomputer systems are increasingly becoming of primary interest for scalable performance. Due to their distributed memory they require use of the message-passing paradigm which, however, is considered as low level programming. Remote access facilities and reliable emulation of shared memory can hide message-passing behind a more abstract interaction protocol. In this paper we address parallel programming and investigate the special requirements to be met by shared objects. We present a class hierarchy which serves as a programming environment for highly parallel, scalable computers. The class hierarchy provides base classes for communication facilities along with a global object name space. We introduce composite virtual objects as object-oriented abstractions implemented as a group of elementary objects. Base classes for shared composite virtual objects emulating fundamental and derived data types in C+ + have been implemented. Examples show how run-time efficient the introduced approach is and how it impacts the code in terms of programming style.