MPI_GET_PROCESSOR_NAME(3)

👑 MPI_Get_processor_name 👑

okay so bestie, this is the Open MPI manual, section 3 — MPI_Get_processor_name(3) if we're being formal, which we are not 💅. let's get into it ✨

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🌸 NAME 🌸

MPI_Get_processor_name — gets the name of the processor. that's the whole assignment. short, sweet, iconic 👑

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✨ SYNTAX ✨

💖 C Syntax

#include <mpi.h>

int MPI_Get_processor_name(char *name, int *resultlen)

🎀 Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'

MPI_GET_PROCESSOR_NAME(NAME, RESULTLEN, IERROR)
    CHARACTER*(*)   NAME
    INTEGER     RESULTLEN, IERROR

🦋 Fortran 2008 Syntax

USE mpi_f08

MPI_Get_processor_name(name, resultlen, ierror)
    CHARACTER(LEN=MPI_MAX_PROCESSOR_NAME), INTENT(OUT) :: name
    INTEGER, INTENT(OUT) :: resultlen
    INTEGER, OPTIONAL, INTENT(OUT) :: ierror

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🌈 OUTPUT PARAMETERS 🌈

• name — a unique specifier for the actual (as opposed to virtual) node. like, the real hardware, not the pretend version of it 🫶
• resultlen — length (in characters) of the result returned in name. so you know how much of that string is actually real ✨
• ierror — Fortran only: error status (integer). the classic.

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💜 DESCRIPTION 💜

so this routine returns the name of the processor it was called on at the moment of the call. yes, at the moment of the call, they said it like that because they mean it 💀

the name is a character string, for maximum flexibility — that's the design philosophy and honestly? we respect it. from this value it must be possible to identify a specific piece of hardware. like, you gotta be able to point at a machine and go "that one."

the argument name must represent storage that is at least MPI_MAX_PROCESSOR_NAME characters long. do not skimp, bestie 🙈

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

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🧚 NOTES 🧚

• you (yes you) must provide at least MPI_MAX_PROCESSOR_NAME space to write the processor name — because processor names can be this long. no cap 🚫🧢
• you should examine the output argument, resultlen, to determine the actual length of the name. don't guess. check. 💅

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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. that's just how it is, fr fr.

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 the 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. everyone. all of them. dramatic on purpose 💀
• 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, it 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, it aborts only the local process 🫠
• MPI_ERRORS_RETURN — returns an error code to the application. the chill one. the "i'll deal with it myself" 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. like, it might just be over. no promises. 🚨

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 🫶 shoutout to The Open MPI Community for the copyright spanning 2003-2026, and this edition is dated Sep 10, 2026 — MPI_GET_PROCESSOR_NAME(3), out. slay 💅✨🦋