MPI_ERROR_STRING(3)

📦
version 5.0.10 · 7 versions
, in ubuntu stonking

✨ MPI_ERROR_STRING(3) ✨

okay bestie, welcome to MPI_Error_STRING from the Open MPI manual, section 3 🎀 this is the page that tells you how to turn a sad little integer error code into actual human-readable text, and honestly? it's giving translator. it's giving "let me explain what he meant by that" 💅

📖 NAME

MPI_Error_string — Returns a string for a given error code. literally just that. you hand it a code, it hands you back the words 🌸

🧾 SYNTAX

✨ C Syntax

#include <mpi.h>

int MPI_Error_string(int errorcode, char *string, int *resultlen)

✨ Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_ERROR_STRING(ERRORCODE, STRING, RESULTLEN, IERROR)
     INTEGER         ERRORCODE, RESULTLEN, IERROR
     CHARACTER*(*)   STRING

✨ Fortran 2008 Syntax

USE mpi_f08
MPI_Error_string(errorcode, string, resultlen, ierror)
     INTEGER, INTENT(IN) :: errorcode
     CHARACTER(LEN=MPI_MAX_ERROR_STRING), INTENT(OUT) :: string
     INTEGER, INTENT(OUT) :: resultlen
     INTEGER, OPTIONAL, INTENT(OUT) :: ierror

📥 INPUT PARAMETER

  • errorcode — the error code that some MPI routine handed you, or an MPI error class. whichever little guy is stressing you out, this is where he goes 🫶

📤 OUTPUT PARAMETERS

  • string — the text that corresponds to the errorcode. the actual answer. the tea. ☕
  • resultlen — length of string. so you know exactly how much of it is real 👑
  • ierror — Fortran only: error status (integer). Fortran girlies, this one's for you 💜

💖 DESCRIPTION

Returns the error string associated with an error code or class. The argument string must represent storage that is at least MPI_MAX_ERROR_STRING characters long.

The number of characters actually written is returned in the output argument, resultlen.

⚠️ okay so read that size thing again bestie — MPI_MAX_ERROR_STRING characters MINIMUM or the vibes will be bad. it's not a suggestion, it's a requirement 💀

🚨 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. like, everybody. all of them. no survivors 😭
  • 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. so it's giving targeted chaos ✨
  • MPI_ERRORS_RETURN — Returns an error code to the application. the polite one. hands you the number and lets you deal 🫶

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.

💀 bestie, that last line is the important one. no cap: MPI is NOT promising your program survives an error. 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.

See also:

  • MPI_Error_class

2003-2026, The Open MPI Community

okay that's the whole page, you ate that 🍓 go forth and translate your error codes like the main character you are 👑

— MPI_ERROR_STRING(3), Open MPI, Sep 10, 2026 — mwah, study safe bestie 💖🦋

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