MPI_WIN_GET_GROUP(3)

💖 MPI_Win_get_group 💖

okay bestie, welcome to the Open MPI manual page for MPI_Win_get_group(3) — yes we're doing this, grab a strawberry 🍓 and let's go.

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✨ NAME ✨

MPI_Win_get_group — returns a duplicate of the group of the communicator used to create the window. that's the whole vibe. 🎀

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🌸 SYNTAX 🌸

🦋 C Syntax

#include <mpi.h>

MPI_Win_get_group(MPI_Win win, MPI_Group *group)

🦋 Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_WIN_GET_GROUP(WIN, GROUP, IERROR)
     INTEGER WIN, GROUP, IERROR

🦋 Fortran 2008 Syntax

USE mpi_f08
MPI_Win_get_group(win, group, ierror)
     TYPE(MPI_Win), INTENT(IN) :: win
     TYPE(MPI_Group), INTENT(OUT) :: group
     INTEGER, OPTIONAL, INTENT(OUT) :: ierror

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🌈 INPUT PARAMETER 🌈

• win — window object (handle). it's giving "which window, bestie" ✨

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🫶 OUTPUT PARAMETERS 🫶

• group — Group of processes that share access to the window (handle). 💫
• ierror — Fortran only: error status (integer). classic.

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👑 DESCRIPTION 👑

MPI_Win_get_group returns a duplicate of the group of the communicator used to create the window associated with win. the group comes back in group. that's it, that's the whole function, and honestly? iconic. lowkey the way it just hands you a whole new group... obsessed. 💅

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💀 ERRORS 💀

Almost all MPI routines return an error value, bestie — C routines hand it back as the return result of the function, and Fortran routines tuck it into the last argument. two different love languages, same energy.

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. no survivors, no cap.
• 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. polite. 🎀

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. fr fr, plan accordingly. 💀

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.

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📜 Copyright 📜

2003-2026, The Open MPI Community

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and that's the whole page, bestie!! 🦋✨ this one came from Open MPI, and the version/date stamp on it is Sep 10, 2026 — go forth and get that group, you absolute main character. 💜👑🌸