MPI_FILE_CREATE_ERRHANDLER(3)

💖 MPI_FILE_CREATE_ERRHANDLER 💖

okay bestie, sit down, we're doing the Open MPI manual pages and honestly? this one is a bop. it's MPI_FILE_CREATE_ERRHANDLER from the Open MPI crew, and it's all about ✨ Creates an MPI-style error handler that can be attached to a file. ✨ like, you're literally building a custom lil safety net for your file ops. main character energy fr fr.

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✨ SYNTAX ✨

C Syntax 🎀

#include <mpi.h>

int MPI_File_create_errhandler(MPI_File_errhandler_function *function,
     MPI_Errhandler *errhandler)

Fortran Syntax 🌸

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_FILE_CREATE_ERRHANDLER(FUNCTION, ERRHANDLER, IERROR)
     EXTERNAL        FUNCTION
     INTEGER ERRHANDLER, IERROR

Fortran 2008 Syntax 🦋

USE mpi_f08
MPI_File_create_errhandler(file_errhandler_fn, errhandler, ierror)
     PROCEDURE(MPI_File_errhandler_function) :: file_errhandler_fn
     TYPE(MPI_Errhandler), INTENT(OUT) :: errhandler
     INTEGER, OPTIONAL, INTENT(OUT) :: ierror

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💀 DEPRECATED TYPE NAME NOTE 💀

sooo, not to be dramatic but: MPI-2.2 deprecated the MPI_File_errhandler_fn type in favor of MPI_File_errhandler_function. Open MPI supports both names (indeed, the _fn names are typedefs to the _function names). so like, the old one still works, she's just retired. wearing sunglasses indoors. iconic but over. 💅

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🌟 INPUT PARAMETER 🌟

• function — your very own user-defined error handling procedure (function). yes YOU get to write it, go off 👑

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🫶 OUTPUT PARAMETERS 🫶

• errhandler — MPI error handler (handle).
• ierror — Fortran only: Error status (integer).

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💜 DESCRIPTION 💜

okay so MPI_Comm_create_errhandler creates an error handler that can be attached to file operations. (yes the name says Comm, no that is not a typo, that's just what the page says, don't come for me 🙈)

In C, the user routine should be a function of type MPI_File_errhandler_function, which is defined as

typedef void (MPI_File_errhandler_function)(MPI_File *, int *, ...);

The first argument is the file in use. The second is the error code to be returned by the MPI routine that raised the error. two args, that's the whole vibe check. cute.

In the Fortran language, the user routine should be of the form:

SUBROUTINE FILE_ERRHANDLER_FUNCTION(FILE, ERROR_CODE, ...)
    INTEGER FILE, ERROR_CODE

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😭 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. it's giving nuclear option 💀
• 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. the chill one 🧊

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. so like... no cap, do not assume you survive this. ⚠️

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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that's the whole page bestie, you ate it UP 🍓✨ go build that error handler, you absolute legend 💖🌈

Open MPI, openmpi man pages, dated Sep 10, 2026 — same energy, same page, only cuter 🎀 periodt.