plucky (3) MPI_Win_shared_query.openmpi.3.gz

SYNTAX

   C Syntax
          #include <mpi.h>

          int MPI_Win_shared_query (MPI_Win win, int rank, MPI_Aint *size,
                                    int *disp_unit, void *baseptr)

   Fortran Syntax
          USE MPI
          ! or the older form: INCLUDE 'mpif.h'
          MPI_WIN_SHARED_QUERY(WIN, RANK, SIZE, DISP_UNIT, BASEPTR, IERROR)
                  INTEGER WIN, RANK, DISP_UNIT, IERROR
                  INTEGER(KIND=MPI_ADDRESS_KIND) SIZE, BASEPTR

   Fortran 2008 Syntax
          USE mpi_f08
          MPI_Win_shared_query(win, rank, size, disp_unit, baseptr, ierror)
               USE, INTRINSIC :: ISO_C_BINDING, ONLY : C_PTR
               TYPE(MPI_Win), INTENT(IN) :: win
               INTEGER, INTENT(IN) :: rank
               INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(OUT) :: size
               INTEGER, INTENT(OUT) :: disp_unit
               TYPE(C_PTR), INTENT(OUT) :: baseptr
               INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETERS

       • win: Shared memory window object (handle).

       • rank: Rank in the group of window win (non-negative integer) or MPI_PROC_NULL.

OUTPUT PARAMETERS

       • size: Size of the window segment (non-negative integer).

       • disp_unit: Local unit size for displacements, in bytes (positive integer).

       • baseptr: Address for load/store access to window segment (choice).

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

DESCRIPTION

       MPI_Win_shared_query   queries  the  process-local  address  for  remote  memory  segments  created  with
       MPI_Win_allocate_shared. This function can return different process-local addresses for the same physical
       memory  on  different  processes.  The returned memory can be used for load/store accesses subject to the
       constraints defined in MPI-3.1 section 11.7. This function can only be  called  with  windows  of  flavor
       MPI_WIN_FLAVOR_SHARED.   If  the  passed  window  is  not  of  flavor  MPI_WIN_FLAVOR_SHARED,  the  error
       MPI_ERR_RMA_FLAVOR is raised. When rank is MPI_PROC_NULL, the pointer, disp_unit, and size  returned  are
       the pointer, disp_unit, and size of the memory segment belonging the lowest rank that specified size > 0.
       If all processes in the group attached to the window specified size = 0, then the call returns size  =  0
       and a baseptr as if MPI_Alloc_mem was called with size = 0.

C NOTES

       The  parameter  baseptr  is  of  type  void * to allow passing any pointer object for this parameter. The
       provided argument should be a pointer to a pointer of arbitrary type (e.g. void **).

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_Alloc_mem

          • MPI_Win_allocate_shared

COPYRIGHT

       2003-2025, The Open MPI Community

                                                  Feb 17, 2025                           MPI_WIN_SHARED_QUERY(3)