MPI_Group_toint(3)

💖 MPI_Group_toint(3) 💖

okay bestie, welcome to the MPI manual, section 3 — yes, that MPI, the message passing icon herself. today's episode: turning a group into a lil integer. no cap.

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✨ NAME ✨

MPI_Group_toint — converts MPI_Group to an integer handle. that's it. that's the whole job. she's a one-trick pony and she ate. 👑

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🌸 SYNOPSIS 🌸

int MPI_Group_toint(MPI_Group group)

like. look at her. one arg. one return. main character energy 🫶

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🎀 INPUT PARAMETERS 🎀

• group — the group. it's a handle. that's the vibe. 💅

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🦋 THREAD AND INTERRUPT SAFETY 🦋

okay so this is the important part, don't scroll past it, i'm literally begging 🙈

This routine is thread-safe. what does that mean for us? it means you can let multiple threads run this bad boy at the same time with no user-provided thread locks whatsoever — no mutex, no stress, no "wait whose turn is it" energy. iconic. ✨

⚠️ BUT. and this is a big but. the routine is not interrupt safe. she's thread-safe, not interrupt-safe, those are two different girlies, don't get it twisted 💀

Typically, this is due to the use of memory allocation routines such as malloc or other non-MPICH runtime routines that are themselves not interrupt-safe. so yeah — it's not her fault, it's the malloc of it all. 🌈

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lowkey a tiny function with a big heart. go convert those groups, bb. i'm obsessed. 🍓

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that's the whole page, bestie — written for MPI_Group_toint(3) in the MPI manual, dated 4/10/2026. drink water, unmalloc your feelings, and see you in the next manpage 💜🧚💅