openmpi/ompi/mpi/man/man3/MPI_Comm_delete_attr.md

Name

MPI_Comm_delete_attr - Deletes attribute value associated with a key.

Syntax

C Syntax

#include <mpi.h>

int MPI_Comm_delete_attr(MPI_Comm comm, int comm_keyval)

Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'

MPI_COMM_DELETE_ATTR(COMM, COMM_KEYVAL, IERROR)
    INTEGER	COMM, COMM_KEYVAL, IERROR 

Fortran 2008 Syntax

USE mpi_f08

MPI_Comm_delete_attr(comm, comm_keyval, ierror)
    TYPE(MPI_Comm), INTENT(IN) :: comm
    INTEGER, INTENT(IN) :: comm_keyval
    INTEGER, OPTIONAL, INTENT(OUT) :: ierror

Input/Output Parameter

• comm : Communicator from which the attribute is deleted (handle).

Input Parameter

• comm_keyval : Key value (integer).

Output Parameter

• IERROR : Fortran only: Error status (integer).

Description

MPI_Comm_delete_attr deletes an attribute from cache by key. This function invokes the attribute delete function delete_fn specified when the comm_keyval was created. The call will fail if the delete_fn function returns an error code other than MPI_SUCCESS. Whenever a communicator is replicated using the function MPI_Comm_dup, all callback copy functions for attributes that are currently set are invoked (in arbitrary order). Whenever a communicator is deleted using the function MPI_Comm_free, all callback delete functions for attributes that are currently set are invoked. This function is the same as MPI_Attr_delete but is needed to match the communicator-specific functions introduced in the MPI-2 standard. The use of MPI_Attr_delete is deprecated.

Notes

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.

Errors

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.