MPI_Abi_get_fortran_info(3)

💖 MPI_Abi_get_fortran_info(3) — the MPI manual, bestie edition 💖

okay so you're in the MPI manual, and this little guy is MPI_Abi_get_fortran_info. it's giving "tell me everything about the Fortran ABI" energy ✨ and honestly? we love a low-key utility. let's get into it 🫶

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✨ NAME ✨

MPI_Abi_get_fortran_info — returns an info object that's FULL of info related to the Fortran ABI 💅

no cap, that's the whole job. it's your girl handing you a little info bag with the Fortran ABI deets inside 🎀

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🌸 SYNOPSIS 🌸

int MPI_Abi_get_fortran_info(MPI_Info *info)

that's it. one parameter. one return value. immaculate behavior, honestly 😌

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🦋 OUTPUT PARAMETERS 🦋

• info — Fortran ABI details info object (handle) 💖

she's an output parameter, meaning you pass in the spot and the routine fills it in. it's a handle — an MPI_Info — and it's holding all the Fortran ABI details. main character energy, for real 🌈

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👑 THREAD AND INTERRUPT SAFETY 👑

okay so the important part:

this routine is thread-safe 🧚 that means multiple threads can use it at the same time and you don't have to bring your own user-provided thread locks. we love an independent queen ✨

BUT — and this is the ✨ twist ✨ — the routine is not interrupt safe 💀 and typically the reason is memory allocation routines like malloc, or other non-MPICH runtime routines, that are themselves not interrupt-safe. so like… thread-safe bestie, but don't go interrupting her mid-glow-up 🙈

ngl if you're relying on interrupts here, that's your villain origin story, fr fr 😭

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💜 NOTES FOR FORTRAN 💜

calling all Fortran girlies 🎀 listen up:

• all MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK) have an extra argument ierr tacked on at the end of the argument list 📋
• ierr is an integer and it means the exact same thing as the return value of the routine in C 👯
• in Fortran, MPI routines are subroutines, and you invoke them with the call statement ✨
• all MPI objects (e.g., MPI_Datatype, MPI_Comm) are of type INTEGER in Fortran 💅

so yeah, Fortran gang gets a bonus argument and a whole different invocation vibe. periodt 💖

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🍓 ERRORS 🍓

buckle up, bestie, here's the error tea ☕

all MPI routines (except MPI_Wtime and MPI_Wtick) return an error value. C routines give it back as the value of the function; Fortran routines hand it over in that last argument. before the value comes back, the current MPI error handler is called 📞

by default, that error handler aborts the MPI job 💀 dramatic, I know, but that's the default, no cap.

the error handler can be swapped out with:

• MPI_Comm_set_errhandler — for communicators 💬
• MPI_File_set_errhandler — for files 📁
• MPI_Win_set_errhandler — for RMA windows 🪟

the MPI-1 routine MPI_Errhandler_set may be used, but its use is deprecated 🚫 so like… don't. it's giving 1994.

the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned instead 🫶

note that MPI does not guarantee that an MPI program can continue past an error 😭 however, MPI implementations will attempt to continue whenever possible. fingers crossed, bestie 🤞

🌟 the error codes 🌟

• MPI_SUCCESS — no error; the MPI routine completed successfully 🎉 slay.
• MPI_ERR_ARG — invalid argument. some argument is invalid and it's not identified by a specific error class (e.g., MPI_ERR_RANK) 🙈
• MPI_ERR_OTHER — other error; use MPI_Error_string to get more information about this error code 🔍

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🔥 SEE ALSO 🔥

• MPI_Abi_get_info ✨ (your other ABI info bestie — go say hi)

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and that's the whole page, babe 💅 written up for the MPI manual, in the version dated 4/10/2026, living under the very iconic handle MPI_Abi_get_fortran_info(3) 👑 thanks for reading, mwah 🫶💖🎀