MPI_Barrier(3OpenMPI) MPI_Barrier(3OpenMPI)
NAME
MPI_Barrier - Blocks until all processes have reached this routine.
SYNTAX
C Syntax
#include <mpi.h>
int MPI_Barrier(MPI_Comm comm)
Fortran Syntax
INCLUDE 'mpif.h'
MPI_BARRIER(COMM, IERROR)
INTEGER COMM, IERROR
C++ Syntax
#include <mpi.h>
void MPI::Comm::Barrier() const = 0
INPUT PARAMETER
comm Communicator (handle).
OUTPUT PARAMETER
IERROR Fortran only: Error status (integer).
DESCRIPTION
Blocks the caller until all group members have called it; the call
returns at any process only after all group members have entered the
call.
WHEN COMMUNICATOR IS AN INTER-COMMUNICATOR
When the communicator is an inter-communicator, the barrier operation
is performed across all processes in both groups. All processes in the
first group may exit the barrier when all processes in the second group
have entered the barrier.
ERRORS
Almost all MPI routines return an error value; C routines as the value
of the function and Fortran routines in the last argument. C++ func-
tions do not return errors. If the default error handler is set to
MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
will be used to throw an MPI:Exception object.
Before the error value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job, except for
I/O function errors. The error handler may be changed with
MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN
may be used to cause error values to be returned. Note that MPI does
not guarantee that an MPI program can continue past an error.
SEE ALSO
MPI_Bcast(3)
Open MPI 1.2 September 2006 MPI_Barrier(3OpenMPI)
Mac OS X 10.6 - Generated Thu Sep 17 20:12:50 CDT 2009