NAME

MPI_NULL_COPY_FN - Helper function to not duplicate an attribute

SYNOPSIS

#include <mpi.h> 
int MPI_NULL_COPY_FN(MPI_Comm comm , int keyval , void *extra_state , void *attr_in ,
	 void *attr_out , int *flag ); 

INPUT PARAMETERS

comm - communicator (handle)

keyval - key value (handle)

extra_state - extra user-controlled state (void pointer handle)

attr_in - original attribute (void pointer handle)

OUTPUT PARAMETERS

attr_out - new attribute (void pointer handle)

flag - set to 1 so that new attribute isused (boolean)

DESCRIPTION

The MPI_NULL_COPY_FN() function is used as a helper for the MPI_Keyval_create() function. If used as a copy function pointer parameter, it tells MPI_Keyval_create() that the attributes to this key should not be copied whenever a communicator is duplicated.

It effectively sets flag to zero so that the new communicator does not use the old attribute.

However, in this implementation of MPI, this function is not actually implemented. It is a special NULL pointer parameter to MPI_Keyval_create() and thus should not be called directly.

There is no profiling version of this function.

ERRORS

All MPI routines except for MPI_Wtime and MPI_Wtick return an error value. The the current MPI error handler is invoked if this return value is not MPI_SUCCESS. The default error handler aborts, but this may be changed with by using the MPI_Errhandler_set() function. The predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned instead. Note that MPI does not guarentee that an MPI program can continue past an error. In this implementation, all errors except MPI_ERR_INTERN or MPI_ERR_OTHER should always be recoverable.

SEE ALSO

MPI_DUP_FN (3) MPI_NULL_DELETE_FN (3) MPI_Keyval_create (3) MPI_Keyval_free (3) MPI_Attr_put (3) MPI_Attr_get (3) MPI_Attr_delete (3)

• Lockless
• MPI Documentation
• MPI_NULL_COPY_FN