MPIX_Delete_error_string(3)

💖 MPIX_Delete_error_string(3) 💖

okay so bestie, welcome to section 3 of the MPI manual, and today we're deleting things. responsibly. 🎀

✨ NAME ✨

MPIX_Delete_error_string — Delete the error string associated with an MPI error code or class

like, it's giving cleanup era. 🧹✨

🌸 SYNOPSIS 🌸

int MPIX_Delete_error_string(int errorcode)

🫶 INPUT PARAMETERS 🫶

• errorcode — the value of the error code whose string is to be removed (integer). yes it's an int, no it's not optional, we love a required arg 💅

💜 NOTES 💜

ngl this part matters. According to the MPI 4.1 standard, it is erroneous to call MPI_Delete_error_string for an error code or class with a value less than or equal to MPI_ERR_LASTCODE. so basically: you cannot replace the predefined error messages with this routine. they are not yours to delete, they are the community's. 🙈

fr fr, don't try it. the predefined messages stay put.

🔥 THREAD AND INTERRUPT SAFETY 🔥

This routine is thread-safe. that means it can be safely used by multiple threads without needing any user-provided thread locks. no mutexes, no stress, we're chill. 😌

BUT. it is not interrupt safe. typically that's because of memory allocation routines like malloc or other non-MPICH runtime routines that are themselves not interrupt-safe. so like... thread-safe yes, interrupt-safe no. know the difference, iykyk. 💀

🌈 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 are invoked with the call statement.

All MPI objects (e.g., MPI_Datatype, MPI_Comm) are of type INTEGER in Fortran.

so yes, Fortran besties, you get a bonus ierr at the end. it's a gift. 🎁

💅 ERRORS 💅

All MPI routines (except MPI_Wtime and MPI_Wtick) return an error value; C routines as the value of the function and Fortran routines in the last argument. Before the value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job. 😭

The error handler may be changed with MPI_Comm_set_errhandler (for communicators), MPI_File_set_errhandler (for files), and MPI_Win_set_errhandler (for RMA windows). The MPI-1 routine MPI_Errhandler_set may be used but its use is deprecated. ⚠️

The predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error; however, MPI implementations will attempt to continue whenever possible.

the codes you might see, in all their glory:

• MPI_SUCCESS — No error; MPI routine completed successfully. we love a clean run, slay. ✨
• MPI_ERR_OTHER — Other error; use MPI_Error_string to get more information about this error code. it's giving "mystery, but make it documented". 🕵️

---

and that's the whole page, bestie!! this little icon dropped on 2/22/2022, and yeah it's still filed right back under MPIX_Delete_error_string(3) where it belongs. go forth and delete only the error strings you're actually allowed to delete. mwah. 💋🦋