SYNTAX

   C Syntax
          #include <mpi.h>

          MPI_Win_attach(MPI_Win win, void *base, MPI_Aint size)

          MPI_Win_detach(MPI_Win win, void *base)

   Fortran Syntax
          USE MPI
          ! or the older form: INCLUDE 'mpif.h'
          MPI_WIN_ATTACH(WIN, BASE, SIZE, IERROR)
               <type> BASE(*)
               INTEGER(KIND=MPI_ADDRESS_KIND) SIZE
               INTEGER WIN, IERROR

          MPI_WIN_DETACH(WIN, BASE, IERROR)
               <type> BASE(*)
               INTEGER WIN, IERROR

   Fortran 2008 Syntax
          USE mpi_f08
          MPI_Win_attach(win, base, size, ierror)
               TYPE(MPI_Win), INTENT(IN) :: win
               TYPE(*), DIMENSION(..), INTENT(IN) :: base
               INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(IN) :: size
               INTEGER, OPTIONAL, INTENT(OUT) :: ierror

          MPI_Win_detach(win, base, ierror)
               TYPE(MPI_Win), INTENT(IN) :: win
               TYPE(*), DIMENSION(..), INTENT(IN) :: base
               INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETERS

       • win: A window that was created with MPI_Win_create_dynamic

       • base: Initial address of window (choice).

       • size: Size of window in bytes (nonnegative integer).

OUTPUT PARAMETERS

       • win: Window object returned by the call (handle).

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

DESCRIPTION

       MPI_Win_attach is a one-sided MPI communication call used  to  attach  a  memory  region  of  size  bytes
       starting  at  address  base  to  a  window  for  RMA  access. The window win must have been created using
       MPI_Win_create_dynamic. Multiple non-overlapping memory regions may  be  attached  to  the  same  dynamic
       window. Attaching overlapping memory regions to the same dynamic window is erroneous.

       If the base value used by MPI_Win_attach was allocated by MPI_Alloc_mem, the size of the window can be no
       larger than the value set by the MPI_Alloc_mem function.

       MPI_Win_detach  can  be  used  to detach a previously attached memory region from win. The memory address
       base and win must match arguments passed to a previous call to MPI_Win_attach.

NOTES

       Use memory allocated by MPI_Alloc_mem to guarantee properly aligned  window  boundaries  (such  as  word,
       double-word, cache line, page frame, and so on).

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.

COPYRIGHT

       2003-2025, The Open MPI Community

                                                  Feb 17, 2025                                 MPI_WIN_DETACH(3)