MPI_Comm_free - Mark a communicator object for deallocation.
184.108.40.206.1. C Syntax
#include <mpi.h> int MPI_Comm_free(MPI_Comm *comm)
220.127.116.11.2. Fortran Syntax
USE MPI ! or the older form: INCLUDE 'mpif.h' MPI_COMM_FREE(COMM, IERROR) INTEGER COMM, IERROR
18.104.22.168.3. Fortran 2008 Syntax
USE mpi_f08 MPI_Comm_free(comm, ierror) TYPE(MPI_Comm), INTENT(INOUT) :: comm INTEGER, OPTIONAL, INTENT(OUT) :: ierror
22.214.171.124. INPUT PARAMETER
comm: Communicator to be destroyed (handle).
126.96.36.199. OUTPUT PARAMETER
IERROR: Fortran only: Error status (integer).
This operation marks the communicator object for deallocation. The handle is set to MPI_COMM_NULL. Any pending operations that use this communicator will complete normally; the object is actually deallocated only if there are no other active references to it. This call applies to intracommunicators and intercommunicators. Upon actual deallocation, the delete callback functions for all cached attributes (see Section 5.7 in the MPI-1 Standard, “Caching”) are called in arbitrary order.
Note that it is not defined by the MPI standard what happens if the delete_fn callback invokes other MPI functions. In Open MPI, it is not valid for delete_fn callbacks (or any of their children) to add or delete attributes on the same object on which the delete_fn 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.
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.