MPI_Win_attach, MPI_Win_detach - One-sided MPI call that attaches / detaches a memory region to / from a window object for RMA operations.
19.2.429.1.1. C Syntax
#include <mpi.h> MPI_Win_attach(MPI_Win win, void *base, MPI_Aint size) MPI_Win_detach(MPI_Win win, void *base)
19.2.429.1.2. 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
19.2.429.1.3. 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
19.2.429.2. 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).
19.2.429.3. OUTPUT PARAMETERS
win: Window object returned by the call (handle).
ierror: Fortran only: Error status (integer).
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.
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).
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_FATALCauses the program to abort all connected MPI processes.
MPI_ERRORS_ABORTAn 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_RETURNReturns an error code to the application.
MPI applications can also implement their own error handlers by calling:
MPI_Session_create_errhandler then MPI_Session_set_errhandler or at MPI_Session_init
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 standard for more information.