MPI_Comm_toint(3)

💖 MPI_Comm_toint(3) — the MPI girlies' guide 💖

okay so bestie, welcome to the MPI section of the manual, page MPI_Comm_toint(3) 🎀 this one is short and sweet and honestly kinda iconic for it

---

✨ NAME ✨

MPI_Comm_toint — converts MPI_Comm to an integer handle 🦋

like, it takes your cute little communicator and hands you back a whole integer. the way that it just does that?? no cap.

---

🌸 SYNOPSIS 🌸

int MPI_Comm_toint(MPI_Comm comm)

---

🫶 INPUT PARAMETERS 🫶

• comm — communicator (handle) 💅 this is the thing you're converting. that's it. that's the whole input. she's lowkey easy like that.

---

🔥 THREAD AND INTERRUPT SAFETY 🔥

okay so here's the tea, bestie, and it's important so pay attention 👑

This routine is thread-safe. what that means fr fr is that this routine may be safely used by multiple threads without the need for any user-provided thread locks 🧚 no mutexes, no semaphores, no extra work on your end, she handles herself. main character energy honestly.

However — and this is the part where you go 😭 — the routine is not interrupt safe. 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 like, threads? yes bestie, go off. interrupts? absolutely not, do not pass go 🙈

not me warning you that the not-interrupt-safe part comes from malloc and other non-MPICH runtime routines being not interrupt-safe themselves… iykyk, it's giving inherited chaos 💜

---

and that's the whole page, periodt 💖 go forth and convert your communicators, you absolute legend 👑

---

sending you off with love from the <strong>MPI</strong> manual, page MPI_Comm_toint(3), dated <strong>4/10/2026</strong> 🎀✨ mwah, slay, bye 💅🌈