# 4.2. Communicator argument

Up: Collective Communication Next: Barrier synchronization Previous: Introduction and Overview

The key concept of the collective functions is to have a ``group'' of participating processes. The routines do not have a group identifier as an explicit argument. Instead, there is a communicator argument. For the purposes of this chapter, a communicator can be thought of as a group identifier linked with a context. An inter-communicator, that is, a communicator that spans two groups, is not allowed as an argument to a collective function.

Up: Collective Communication Next: Barrier synchronization Previous: Introduction and Overview

Return to MPI 1.1 Standard Index
Return to MPI-2 Standard Index
Return to MPI Forum Home Page

MPI-1.1 of June 12, 1995
HTML Generated on August 6, 1997