4.2. Communicator argument


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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


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