MPI_Grequest_start(3)

NAME
     MPI_Grequest_start - Create new generalized request

SYNOPSIS
     C:

          #include <mpi.h>

          typedef MPI_Grequest_query_function(void *extra_state,
                                              MPI_Status *status);
          typedef MPI_Grequest_free_function(void *extra_state);
          typedef MPI_Grequest_cancel_function(void *extra_state,
                                               int complete);

          int MPI_Grequest_start(query_fn, free_fn, cancel_fn,
                                 extra_state, request);

          MPI_Grequest_query_function    *query_fn;
          MPI_Grequest_free_function     *free_fn;
          MPI_Grequest_cancel_function   *cancel_fn;
          void                           *extra_state;
          MPI_Request                    *request;


     C++:   (Not currently implemented)

          #include <mpi.h>

          typedef int MPI::Grequest::Query_function(void* extra_state,
                                                    MPI::Status& status);
          typedef int MPI::Grequest::Free_function(void* extra_state);
          typedef int MPI::Grequest::Cancel_function(void* extra_state,
                                                     bool complete);

          static MPI::Grequest MPI::Grequest::Start(
                            const MPI::Grequest::Query_function  query_fn,
                            const MPI::Grequest::Free_function   free_fn,
                            const MPI::Grequest::Cancel_function cancel_fn,
                            void *extra_state);


     Fortran:

          INCLUDE "mpif.h" (or USE MPI)

          SUBROUTINE MPI_GREQUEST_START(query_fn, free_fn, cancel_fn, extra_state, request, ierr)
          EXTERNAL query_fn, free_fn, cancel_fn
          INTEGER (KIND=MPI_ADDRESS_KIND) extra_state
          INTEGER request
          INTEGER ierr
          END
          SUBROUTINE GREQUEST_QUERY_FUNCTION(extra_state, status, ierr)
          INTEGER(KIND=MPI_ADDRESS_KIND) extra_state
          INTEGER status(MPI_STATUS_SIZE), ierr
          END

          SUBROUTINE GREQUEST_FREE_FUNCTION(extra_state, ierr)
          INTEGER(KIND=MPI_ADDRESS_KIND) extra_state
          INTEGER ierr
          END

          SUBROUTINE GREQUEST_CANCEL_FUNCTION(extra_state, complete, ierr)
          INTEGER(KIND=MPI_ADDRESS_KIND) extra_state
          LOGICAL complete
          INTEGER ierr
          END


STANDARDS
     This release implements the MPI 2.0 standard, as documented by the MPI
     Forum in the July 1997 release of MPI:  A Message Passing Interface
     Standard.

DESCRIPTION
     Calling MPI_Grequest_start() creates a new generalized request.  This
     routine accepts the following parameters:

     query_fn    Specifies the user-written callback function invoked when
                 request status is queried.   (function)

     free_fn     Specifies the user-written callback function invoked when the
                 request is freed.   (function)

     cancel_fn   Specifies the user-written callback function invoked when the
                 request is cancelled.   (function)

     extra_state Specifies a void pointer associated with this request.  Each
                 callback function is passed the extra_state value associated
                 with the request on which it is operating.    (void pointer)

     request     Returns the newly-created generalized request.  (handle)

     ierr        Specifies the error code of the operation.  If no error
                 occured, MPI_SUCCESS is returned.   (integer)

NOTES
     All MPI routines in Fortran (except for MPI_Wtime(3) and MPI_Wtick(3))
     have an additional ierr argument at the end of the argument list.  ierr
     is an integer and has the same meaning as the return value of the routine
     in C.  In Fortran, MPI routines are subroutines and are invoked with the
     CALL statement.  Additionally, in Fortran, all MPI objects (for example,
     MPI_Datatype and MPI_Comm) are of type integer.
SEE ALSO
     MPI_Grequest_complete(3), MPI_Status_set_elements(3),
     MPI_Status_set_cancelled(3)