The Pvm3 Based Implementation of the Grp Function Library

The SEPP (Software Engineering for Parallel Processing) project aims to develop a graphical language based integrated software engineering environment for parallel programs. This needs a compiler to create the executable code from the source code (which is in this case a graphical description). To ensure portability, the code generation is divided into two phases. In the rst phase, a suitable compiler generates a standard ANSI C code containing special function calls to achieve parallelism. This library is referred as GRP function library. In the second phase, a commercial C compiler generates the executable code from the C source. This software structure makes migrating to an other architecture relatively easy, as the GRP function library is the only part of the system which needs to be rewritten. This paper describes the pvm3 implementation of the GRP function library in order to depict a working implementation and to give some hints for the future work. 1 Implementation of the channels Channels are point to point, one way communication media between two processes. A channel can be used to send diierent data types, but the channel direction can not be changed. The pvm3 does not support channel communication , so the implementation has to look after them. (The pvm3 uses a process id, called task id (tid) to send or receive a message.) The channels are represented by the following structure: