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MPI_Comm_dup - Duplicates an existing communicator with all its
cached information.
#include <mpi.h>
int MPI_Comm_dup(MPI_Comm comm, MPI_Comm *newcomm)
USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_COMM_DUP(COMM, NEWCOMM, IERROR)
INTEGER COMM, NEWCOMM, IERROR
USE mpi_f08
MPI_Comm_dup(comm, newcomm, ierror)
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Comm), INTENT(OUT) :: newcomm
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
- comm
- Communicator (handle).
- newcomm
- Copy
of comm (handle).
- IERROR
- Fortran only: Error status (integer).
MPI_Comm_dup
duplicates the existing communicator comm with associated key values. For
each key value, the respective copy callback function determines the attribute
value associated with this key in the new communicator; one particular
action that a copy callback may take is to delete the attribute from the
new communicator. Returns in newcomm a new communicator with the same group,
any copied cached information, but a new context (see Section 5.7.1 of the
MPI-1 Standard, "Functionality").
This operation is used to provide
a parallel library call with a duplicate communication space that has the
same properties as the original communicator. This includes any attributes
(see below) and topologies (see Chapter 6, "Process Topologies," in the
MPI-1 Standard). This call is valid even if there are pending point-to-point
communications involving the communicator comm. A typical call might involve
an MPI_Comm_dup at the beginning of the parallel call, and an MPI_Comm_free
of that duplicated communicator at the end of the call. Other models of
communicator management are also possible.
This call applies to both intra-
and intercommunicators.
Note that it is not defined by the MPI standard
what happens if the attribute copy callback invokes other MPI functions.
In Open MPI, it is not valid for attribute copy callbacks (or any of their
children) to add or delete attributes on the same object on which the attribute
copy callback is being invoked.
Almost all MPI routines return an
error value; C routines as the value of the function and Fortran routines
in the last argument. C++ functions 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.
MPI_Comm_dup_with_info
MPI_Comm_idup
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