<< MPI_Allreduce Message Passing Interface MPI_Bcast >>

MPI_Barrier

Blocks until all processes in the communicator have reached this routine.

Syntax

r = MPI_Barrier(Comm)

Input argument

Comm

a MPI_Comm object.

Output argument

r

integer value: MPI_SUCCESS (0) or MPI_ERR_COMM (5).

Description

This function is used as a synchronization point for all processes in a group. All processes are blocked until every process calls MPI_Barrier.

See also

MPI_Initialized.

Example

mpiexec([modulepath('mpi'), '/examples/help_examples/MPI_Barrier.m'], 4)

if ~MPI_Initialized()
  MPI_Init();
end
my_rank = MPI_Comm_rank ();
num_ranks = MPI_Comm_size();
comm = MPI_Comm_object('MPI_COMM_WORLD');
sleep(my_rank);
MPI_Barrier(comm);
disp(['I am ', int2str(my_rank), ' of ', int2str(num_ranks)]);
if MPI_Initialized()
  MPI_Finalize();
end

History

Version Description
1.0.0 initial version

Author

Allan CORNET

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