Newsgroups: comp.parallel.mpi
From: cattoni@irst.itc.it (Roldano Cattoni)
Subject: MPI_Barrier and Collective Communications
Organization: Istituto Trentino di Cultura - IRST
Date: 22 Feb 1996 09:38:42 GMT
Message-ID: <CATTONI.96Feb22103842@corallo.itc.it>

In the MPI standard document, the examples about collective communication
don't use MPI_Barrier.
I suppose this means that all the processes in a group are syncronized by
the collective call itself; from this follows for example that the two
following pieces of code are equivalent

1:
  MPI_Barrier (comm);
  MPI_Bcast(..., comm);

2:
  MPI_Bcast(..., comm);


It this correct? If true, when MPI_Barrier is useful?

Thanks

	Roldano Cattoni
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