plucky (3) MPI_Type_contiguous.openmpi.3.gz

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SYNTAX

   C Syntax
          #include <mpi.h>

          int MPI_Type_contiguous(int count, MPI_Datatype oldtype,
               MPI_Datatype *newtype)

   Fortran Syntax
          USE MPI
          ! or the older form: INCLUDE 'mpif.h'
          MPI_TYPE_CONTIGUOUS(COUNT, OLDTYPE, NEWTYPE, IERROR)
               INTEGER COUNT, OLDTYPE, NEWTYPE, IERROR

   Fortran 2008 Syntax
          USE mpi_f08
          MPI_Type_contiguous(count, oldtype, newtype, ierror)
               INTEGER, INTENT(IN) :: count
               TYPE(MPI_Datatype), INTENT(IN) :: oldtype
               TYPE(MPI_Datatype), INTENT(OUT) :: newtype
               INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETERS

count: Replication count (nonnegative integer).

       • oldtype: Old datatype (handle).

OUTPUT PARAMETERS

newtype: New datatype (handle).

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

DESCRIPTION

       The  simplest  datatype  constructor  is MPI_Type_contiguous, which allows replication of a datatype into
       contiguous locations.

       newtype is the datatype obtained by concatenating count copies of oldtype. Concatenation is defined using
       the extent of oldtype as the size of the concatenated copies.

       Example:  Let oldtype have type map {(double, 0), (char, 8)}, with extent 16, and let count = 3. The type
       map of the datatype returned by newtype is

          {(double, 0), (char, 8), (double, 16), (char, 24),
          (double, 32), (char, 40)];

       i.e., alternating double and char elements, with displacements 0, 8, 16, 24, 32, 40.

       In general, assume that the type map of oldtype is

          {(type(0), disp(0)),...,(type(n-1), disp(n-1))},

       with extent ex. Then newtype has a type map with count times n entries defined by:

          {(type(0), disp(0)), ...,(type(n-1), disp(n-1)),
          (type(0), disp(0) + ex), ...,(type(n-1),
          disp(n-1) + ex), ...,(type(0), disp(0) + ex * (count - 1)),
          ...,(type(n-1), disp(n-1) + ex * (count - 1))}.

       For more information about derived datatypes, see the Datatypes chapter in the MPI Standard.

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_errhandlerMPI_File_create_errhandler then MPI_File_set_errhandlerMPI_Session_create_errhandler then MPI_Session_set_errhandler or at MPI_Session_initMPI_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.

       2003-2025, The Open MPI Community

                                                  Feb 17, 2025                            MPI_TYPE_CONTIGUOUS(3)