MPI_T_event_handle_get_info(3)

✨ MPI_T_event_handle_get_info ✨

okay bestie, gather round 💖 this one lives in the MPI manual, section 3, and it's literally just a lil function that spills the tea on your event registration. no cap.

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🌸 NAME 🌸

MPI_T_event_handle_get_info — returns a brand new info object stuffed with the hints of the event-registration handle that's associated with event_registration 🎀

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🦋 SYNOPSIS 🦋

int MPI_T_event_handle_get_info(MPI_T_event_registration event_registration,
MPI_Info *info_used)

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💅 INPUT PARAMETERS 💅

• event_registration — the event registration, bestie. it's a handle 🫶

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✨ OUTPUT PARAMETERS ✨

• info_used — the info object that comes back out. also a handle. we love a handle 💖

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🧚 THREAD AND INTERRUPT SAFETY 🧚

okay so this routine is thread-safe, and that's iconic of it. what that means: multiple threads can use it at the same time, and nobody needs to bring their own thread locks. no user-provided locks required, periodt. 🔥

BUT — and this is the part where we gasp 😭 — it is not interrupt safe. typically that's because it uses memory allocation routines like malloc or other non-MPICH runtime routines that are themselves not interrupt-safe. so like, thread-safe? yes. interrupt-safe? absolutely not, bestie 💀

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🌈 ERRORS 🌈

so every single MPI routine (except MPI_Wtime and MPI_Wtick, the two rebellious ones) returns an error value. C routines hand it back as the value of the function; Fortran routines put it in the last argument. and before that value comes back, the current MPI error handler gets called. by default that error handler aborts the whole MPI job 😭 so like, know that going in.

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 also be used, but its use is deprecated 🙈 (we don't do that here).

and if you want errors handed back to you as values instead of nuking the job, use the predefined error handler MPI_ERRORS_RETURN. note that MPI does not guarantee an MPI program can continue past an error; however, MPI implementations will attempt to continue whenever possible. so like… fingers crossed 🤞

here's the full roster of possible error codes, no gatekeeping:

• MPI_SUCCESS — no error, the MPI routine completed successfully. slay 💅
• MPI_T_ERR_INVALID — invalid use of the interface, or bad parameter value(s).
• MPI_T_ERR_INVALID_HANDLE — the handle is invalid. it's giving fake 💀
• MPI_T_ERR_NOT_INITIALIZED — the MPI tool information interface is not initialized. bestie we haven't even started 😭
• MPI_ERR_OTHER — some other error; use MPI_Error_string to get more info about this error code.

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🎀 reminder for the girlies: same sections, same order, same facts — the vibe is the only thing that changed. iykyk 💖

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and that's the whole page, bestie!! 🌟 this was the MPI_T_event_handle_get_info(3) page, dated 4/10/2026, straight out of the MPI mansion. go forth and get that info, queen 👑💜