MPI_Message_toint(3)

💖 MPI_Message_toint 💖

okay so bestie, you know that MPI man page life? this one is like, tiny but mighty, and it lives in the MPI manual, section 3. let's get into it 🫶

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✨ NAME ✨

MPI_Message_toint — converts MPI_Message to an integer handle 🌈

like. that's it. that's the whole job. she takes a message and hands you back an integer. iconic behavior honestly 💅

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🌸 SYNOPSIS 🌸

int MPI_Message_toint(MPI_Message message)

no extra args, no surprises, just the one message going in and an int coming out ✨

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🎀 INPUT PARAMETERS 🎀

• message — the message, which is a handle 🦋

yes bestie, the parameter is literally named after the thing it is, we love a self-explanatory moment 💜

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🧚 THREAD AND INTERRUPT SAFETY 🧚

okay this part is IMPORTANT so pay attention 💖

• This routine is thread-safe. which means — say it with me — it can be safely used by multiple threads and you do not need to bring your own user-provided thread locks. none. zero. she handles it herself, main character energy fr 👑
• BUT. and it's a big but 😭 — this routine is not interrupt safe.

and why, you ask? typically because it uses memory allocation routines like malloc, or other non-MPICH runtime routines, and those things are themselves not interrupt-safe. so the vibe chains all the way down, no cap 💀

bestie please respect the interrupt caveat. it's not a suggestion, it's the whole point of the paragraph 🙈

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🌈 that's the whole page 🌈

ngl it was a short one but we still ate. now go forth and convert those messages into integer handles, you absolute legend 🍓⭐

signing off with the deets: this was the MPI flavor of the manual, dated 4/10/2026, and the page is MPI_Message_toint(3). periodt 💅✨