plucky (3) MPI_Type_create_keyval.openmpi.3.gz

SYNTAX

   C Syntax
          #include <mpi.h>

          int MPI_Type_create_keyval(MPI_Type_copy_attr_function *type_copy_attr_fn,
               MPI_Type_delete_attr_function *type_delete_attr_fn,
               int *type_keyval, void *extra_state)

   Fortran Syntax
          USE MPI
          ! or the older form: INCLUDE 'mpif.h'
          MPI_TYPE_CREATE_KEYVAL(TYPE_COPY_ATTR_FN, TYPE_DELETE_ATTR_FN,
                       TYPE_KEYVAL, EXTRA_STATE, IERROR)
               EXTERNAL TYPE_COPY_ATTR_FN, TYPE_DELETE_ATTR_FN
               INTEGER TYPE_KEYVAL, IERROR
               INTEGER(KIND=MPI_ADDRESS_KIND) EXTRA_STATE

   Fortran 2008 Syntax
          USE mpi_f08
          MPI_Type_create_keyval(type_copy_attr_fn, type_delete_attr_fn, type_keyval,
                       extra_state, ierror)
               PROCEDURE(MPI_Type_copy_attr_function) :: type_copy_attr_fn
               PROCEDURE(MPI_Type_delete_attr_function) :: type_delete_attr_fn
               INTEGER, INTENT(OUT) :: type_keyval
               INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(IN) :: extra_state
               INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETERS

       • type_copy_attr_fn: Copy callback function for type_keyval (function).

       • type_delete_attr_fn: Delete callback function for type_keyval (function).

       • extra_state: Extra state for callback functions.

OUTPUT PARAMETERS

       • type_keyval: Key value for future access (integer).

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

DESCRIPTION

       MPI_Type_create_keyval  generates  a  new attribute key for caching on data types. This routine partially
       replaces MPI_Keyval_create.

       The argument type_copy_attr_fn may be specified as MPI_TYPE_NULL_COPY_FN or  MPI_TYPE_DUP_FN  from  C  or
       Fortran.   MPI_TYPE_NULL_COPY_FN  is  a  function  that  does  nothing  other than returning flag = 0 and
       MPI_SUCCESS. MPI_TYPE_DUP_FN is a simple-minded copy function that sets flag = 1, returns  the  value  of
       attribute_val_in in attribute_val_out, and returns MPI_SUCCESS.

       The  argument  type_delete_attr_fn  may  be  specified  as  MPI_TYPE_NULL_DELETE_FN  from  C  or Fortran.
       MPI_TYPE_NULL_DELETE_FN is a function that does nothing beyond  returning  MPI_SUCCESS.  The  C  callback
       functions are:

          typedef int MPI_Type_copy_attr_function(MPI_Datatype oldtype,
                      int type_keyval, void *extra_state, void *attribute_val_in,
                      void *attribute_val_out, int *flag);

          typedef int MPI_Type_delete_attr_function(MPI_Datatype type, int type_keyval,
                       void *attribute_val, void *extra_state);

       The Fortran callback functions are:

          SUBROUTINE TYPE_COPY_ATTR_FN(OLDTYPE, TYPE_KEYVAL, EXTRA_STATE,
                       ATTRIBUTE_VAL_IN, ATTRIBUTE_VAL_OUT, FLAG, IERROR)
              INTEGER OLDTYPE, TYPE KEYVAL, IERROR
              INTEGER(KIND=MPI_ADDRESS_KIND) EXTRA_STATE,
                  ATTRIBUTE_VAL_IN, ATTRIBUTE_VAL_OUT
              LOGICAL FLAG

          SUBROUTINE TYPE_DELETE_ATTR_FN(TYPE, TYPE_KEYVAL, ATTRIBUTE_VAL, EXTRA_STATE,
                       IERROR)
              INTEGER TYPE, TYPE_KEYVAL, IERROR
              INTEGER(KIND=MPI_ADDRESS_KIND) ATTRIBUTE VAL, EXTRA_STATE

ERRORS

       Almost  all  MPI  routines  return  an  error  value; C routines as the return result of the function and
       Fortran routines in the last argument.

       Before the error value is returned, the current MPI  error  handler  associated  with  the  communication
       object  (e.g.,  communicator, window, file) is called.  If no communication object is associated with the
       MPI call, then the call is considered attached to MPI_COMM_SELF and will call the  associated  MPI  error
       handler.   When   MPI_COMM_SELF   is   not  initialized  (i.e.,  before  MPI_Init/MPI_Init_thread,  after
       MPI_Finalize, or when using the Sessions Model exclusively) the error raises the initial  error  handler.
       The  initial  error handler can be changed by calling MPI_Comm_set_errhandler on MPI_COMM_SELF when using
       the World model, or the mpi_initial_errhandler CLI argument to mpiexec or info  key  to  MPI_Comm_spawn/‐
       MPI_Comm_spawn_multiple.   If no other appropriate error handler has been set, then the MPI_ERRORS_RETURN
       error handler is called for MPI I/O functions and the MPI_ERRORS_ABORT error handler is  called  for  all
       other MPI functions.

       Open MPI includes three predefined error handlers that can be used:

       • MPI_ERRORS_ARE_FATAL Causes the program to abort all connected MPI processes.

       • MPI_ERRORS_ABORT An error handler that can be invoked on a communicator, window, file, or session. When
         called on a communicator, it acts as if MPI_Abort was called on  that  communicator.  If  called  on  a
         window  or file, acts as if MPI_Abort was called on a communicator containing the group of processes in
         the corresponding window or file. If called on a session, aborts only the local process.

       • MPI_ERRORS_RETURN Returns an error code to the application.

       MPI applications can also implement their own error handlers by calling:

       • MPI_Comm_create_errhandler then MPI_Comm_set_errhandler

       • MPI_File_create_errhandler then MPI_File_set_errhandler

       • MPI_Session_create_errhandler then MPI_Session_set_errhandler or at MPI_Session_init

       • MPI_Win_create_errhandler then MPI_Win_set_errhandler

       Note that MPI does not guarantee that an MPI program can continue past an error.

       See the MPI man page for a full list of MPI error codes.

       See the Error Handling section of the MPI-3.1 standard for more information.

       SEE ALSO:

          • MPI_Type_free_keyval

COPYRIGHT

       2003-2025, The Open MPI Community

                                                  Feb 17, 2025                         MPI_TYPE_CREATE_KEYVAL(3)