Open MPI

Constants

The following new constants are available in the mpi module:

integer MPI_PSETOP_NULL
integer MPI_PSETOP_ADD
integer MPI_PSETOP_SUB
integer MPI_PSETOP_REPLACE
integer MPI_PSETOP_MALLEABLE
integer MPI_PSETOP_GROW
integer MPI_PSETOP_SHRINK
integer MPI_PSETOP_UNION
integer MPI_PSETOP_DIFFERENCE
integer MPI_PSETOP_INTERSECTION
integer MPI_PSETOP_SPLIT

These constants are used for the op and type arguments in MPI_Session_dyn_v2a_psetop and MPI_Session_dyn_v2a_query_psetop and represent the respective pset operation.

Note that MPI_PSETOP_SHRINK, MPI_PSETOP_GROW, MPI_PSETOP_ADD and MPI_PSETOP_SUB modify the available resources of the application. The other pset operations only recombine existing process sets.

Subroutines

Analogously to existing Fortran subroutines in the MPI standard, the corresponding Fortran routines have the same name and arguments as their C counterpart. Additionally, an optional integer ierror argument can be added at the end of each call to get the return status of the operation.

The exception is the output_psets argument of MPI_Session_dyn_v2a_psetop and MPI_Session_dyn_v2a_query_psetop. Instead of being allocated by the Open MPI runtime, it requires the user to pre-allocate these. The reason for this is the difficulty of allocating Fortran objects in C. Furthermore, this has an additional benefit: It is easier to broadcast output_psets, as other processes might also allocate output_psets before the call.

String arguments that contain a process set name and are of type IN or INOUT should be able to hold at least MPI_MAX_PSET_NAME_LEN arguments (constant is available in the mpi module). Furthermore, process set names are terminated by filling the rest of the string with blanks (' ', ASCII 0x20).

PSet Data Routines

interface
subroutine MPI_Session_get_pset_data(session, pset_name , coll_pset_name, keys, nkeys, wait, info_used, ierror)
  implicit none
  integer,                        intent(in)  :: session
  character(len=*),               intent(in)  :: coll_pset_name
  character(len=*),               intent(in)  :: pset_name
  character(len=*), dimension(*), intent(in)  :: keys
  integer,                        intent(in)  :: nkeys
  integer,                        intent(in)  :: wait
  integer,                        intent(out) :: info_used
  integer,                        intent(out) :: ierror
end subroutine MPI_Session_get_pset_data
end interface

• Works analogously to the C version.

From the C documentation:

RETURN: 
   - MPI_SUCCESS if operation was successful

Description:   Publishes a key-value pair in the dictionary associated with the given PSet name.
               The PSet name has to exist.

interface
subroutine MPI_Session_set_pset_data (session, pset_name, info_used, ierror)
  implicit none
  integer,          intent(in)  :: session
  character(len=*), intent(in)  :: pset_name
  integer,          intent(in)  :: info_used
  integer,          intent(out) :: ierror
end subroutine MPI_Session_set_pset_data
end interface

• Works analogously to the C version.

From the C documentation:

RETURN: 
   - MPI_SUCCESS if operation was successful
Description:   Looks up a key-value pair in the dictionary associated with the given PSet name.
               The PSet name has to exist.
               The call is collective over the processes in coll_pset_name, i.e. all processes in 
               coll_pset_name have to call this function. All processes are guaranteed to receive the
               same values. mpi://SELF may be used for individual lookups

PSet Operation Routines

interface
subroutine MPI_Session_dyn_v2a_query_psetop (session, coll_pset, input_pset, type, output_psets, noutput, ierror)
  integer,                        intent(in)    :: session
  character(len=*),               intent(in)    :: coll_pset
  character(len=*),               intent(in)    :: input_pset
  integer,                        intent(out)   :: type
  character(len=*), dimension(*), intent(out)   :: output_psets
  integer,                        intent(inout) :: noutput
  integer,                        intent(out)   :: ierror
end subroutine MPI_Session_dyn_v2a_query_psetop
end interface

• output_psets must be pre-allocated by the caller.
• noutput needs to be set to the number of entries in output_psets.
• On sucessful return and type != MPI_PSETOP_NULL, noutput will be set to the number of output psets and the names of the output psets will be located in noutputs.

From the C documentation:

RETURN: 
   - MPI_SUCCESS if operation was successful

Description:   Queries for pending PSet Operation invloving the specified PSet.
               This only applies to PSet operations involving changes of resources:
                  -> MPI_PSETOP_{ADD, SUB; GROW, SHRINK, REPLACE}
               If no pending PSet operation is found for the specified PSet, op will be set to MPI_PSETOP_NULL

interface
subroutine MPI_Session_dyn_v2a_psetop (session, op, input_sets, ninput, output_psets, noutput, info, ierror)
   integer,                        intent(in)    :: session
   integer,                        intent(inout) :: op
   character(len=*), dimension(*), intent(in)    :: input_sets
   integer,                        intent(in)    :: ninput
   character(len=*), dimension(*), intent(inout) :: output_psets
   integer,                        intent(inout) :: noutput
   integer,                        intent(inout) :: info
   integer,                        intent(out)   :: ierror
end subroutine MPI_Session_dyn_v2a_psetop
end interface

• output_psets must be pre-allocated by the caller.
• noutput needs to be set to the number of entries in output_psets.
• On sucessful return noutput will be set to the number of output psets and the names of the output psets will be located in noutputs.

From the C documentation:

RETURN: 
   - MPI_SUCCESS if operation was successful

Description:   Requests the specified PSet Operation to be applied on the input PSets.
               The info object can be used to specify parameters of the operation.
               If successful, the function allocates an array of n_output PSet names.
               It is the callers responsibility to free the PSet names and the output_psets array.

interface
subroutine MPI_Session_dyn_finalize_psetop(session, pset_name, ierror)
  implicit none
  integer,          intent(in)  :: session
  character(len=*), intent(in)  :: pset_name
  integer,          intent(out) :: ierror
end subroutine MPI_Session_dyn_finalize_psetop
end interface

• Works analogously to the C version.

From the C documentation:

RETURN: 
   - MPI_SUCCESS if operation was successful

Description:   Indicates finalization of the PSet Operation.
               This will make the operation unavailable for MPI_Session_dyn_v2a_query_psetop.
               This only applies to PSet operations involving changes of resources:
                  -> MPI_PSETOP_{ADD, SUB; GROW, SHRINK, REPLACE}