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MPI_Comm_free_keyval - Frees attribute key for communicator cache
attribute.
#include <mpi.h>
int MPI_Comm_free_keyval(int *comm_keyval)
INCLUDE ’mpif.h’
MPI_COMM_FREE_KEYVAL(COMM_KEYVAL, IERROR)
INTEGER COMM_KEYVAL, IERROR
#include <mpi.h>
static void MPI::Comm::Free_keyval(int& comm_keyval)
- comm_keyval
-
- IERROR
- Fortran only:
Error status (integer).
MPI_Comm_free_keyval frees an extant
attribute key. This function sets the value of keyval to MPI_KEYVAL_INVALID.
Note that it is not erroneous to free an attribute key that is in use,
because the actual free does not transpire until after all references (in
other communicators on the process) to the key have been freed. These references
need to be explicitly freed by the program, either via calls to MPI_Comm_delete_attr
that free one attribute instance, or by calls to MPI_Comm_free that free
all attribute instances associated with the freed communicator.
This call
is identical to the call MPI_Keyval_free but is needed to match the communicator-specific
creation function introduced in the MPI-2 standard. The use of MPI_Keyval_free
is deprecated.
Key values are global (they can be used with any
and all communicators).
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.
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