MPI_Parrived(3)

💖 MPI_Parrived — the man page, but make it cute 💖

okay bestie, you're reading the MPI manual (that's the library name, she's famous) page for MPI_Parrived, and honestly? this one is a little gem. it's giving "checking in on your partitioned receive like a nosy bestie checking if you've replied yet" energy. ✨

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🌸 NAME 🌸

MPI_Parrived — testing partial completion of partitioned receive operations. like, not the whole thing, just a peek at one partition. lowkey iconic behavior. 💅

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🦋 SYNOPSIS 🦋

int MPI_Parrived(MPI_Request request, int partition, int *flag)

that's it. three little arguments, one big vibe. 🎀

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💌 INPUT PARAMETERS 💌

• request — your partitioned communication request (a handle). this is the main character of the operation. 👑
• partition — the partition you wanna test, and she must be a non-negative integer. no negative partitions, bestie, we don't do that here. 🙈

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🌈 OUTPUT PARAMETERS 🌈

• flag — true if the operation has completed on the specified partition, false if it has not (boolean). it's literally a vibe check on that one partition. ⭐

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🧚 THREAD AND INTERRUPT SAFETY 🧚

this routine is thread-safe. what does that mean for you?? it means multiple threads can use this routine at the same time with no need for any user-provided thread locks. slay, no mutexes required, we love a self-sufficient queen. 💜

BUT — and this is important, bestie — the routine is not interrupt safe. the reason, typically, is the use of memory allocation routines such as malloc or other non-MPICH runtime routines that are themselves not interrupt-safe. so like... she's safe with her friends but don't interrupt her mid-sentence. 😭

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🍓 NOTES FOR FORTRAN 🍓

all MPI routines in Fortran — except for MPI_WTIME and MPI_WTICK — have an additional argument ierr at the end of the argument list. ierr is an integer and has the same meaning as the return value of the routine in C. 📝

in Fortran, MPI routines are subroutines, and they're invoked with the call statement.

also: all MPI objects (e.g., MPI_Datatype, MPI_Comm) are of type INTEGER in Fortran. that's just how she is over there. 💫

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💀 ERRORS 💀

okay so, all MPI routines (except MPI_Wtime and MPI_Wtick) return an error value — C routines return it as the value of the function, and Fortran routines put it in the last argument.

before that value is returned, the current MPI error handler is called. and by default?? this error handler aborts the MPI job. yes bestie, the whole job. dramatic. 😭

the error handler can be changed 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. we don't stan deprecated things. 🙅

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

⚠️ heads up: MPI does not guarantee that an MPI program can continue past an error. however, MPI implementations will attempt to continue whenever possible. so there's hope, but no promises. 🫶

here come the error codes:

• MPI_SUCCESS — no error; the MPI routine completed successfully. we love a happy ending. ✅
• MPI_ERR_ARG — invalid argument. some argument is invalid and is not identified by a specific error class (e.g., MPI_ERR_RANK). rude of it to be so vague, honestly. 😤
• MPI_ERR_REQUEST — invalid MPI_Request. either null, or, in the case of a MPI_Start or MPI_Startall, not a persistent request. 🔥
• MPI_ERR_OTHER — other error; use MPI_Error_string to get more information about this error code. the catch-all, the mystery box. 💅

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and that's the whole page, bestie!! 🌸✨ nothing skipped, every flag and error code present and accounted for. you ate. 💖

<tada>this has been the MPI manual (that's the header manual name, fr fr) for MPI_Parrived(3), and the very last line of the original was the source MPI with date 4/10/2026 — so consider this your cute sign-off: MPI, 4/10/2026, MPI_Parrived(3), periodt. 💅🎀🦋</tada>