MPI_Comm_set_name(3)

💖 MPI_Comm_set_name — giving your communicator a lil name tag 💖

okay so bestie, welcome to the MPI_Comm_set_name(3) page from the LAM/MPI manual 💅 this one's short, sweet, and honestly iconic.

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✨ NAME ✨

MPI_Comm_set_name — Set a name on a communicator 🏷️

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🌸 SYNOPSIS 🌸

#include <mpi.h>
int
MPI_Comm_set_name(MPI_Comm comm, char *name)

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🎀 INPUT PARAMETERS 🎀

• comm — the Communicator, aka the lil group chat you're naming 🫶
• name — Pointer to the name of communicator. yeah. it's a pointer. it's always a pointer 🙈

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🦋 NOTES 🦋

so this function associates a name with a communicator, which is lowkey useful for debugging purposes. and the way that MPI_Comm_get_name exists so you can retrieve the name that was previously set with MPI_Comm_set_name? yeah. they're a matching set. iykyk ✨

Now here's the tea, bestie: MPI_COMM_WORLD, MPI_COMM_SELF, and the parent communicator (if an application was launched via MPI_Comm_spawn or MPI_Comm_spawn_multiple) already come with the predefined names MPI_COMM_WORLD, MPI_COMM_SELF, and MPI_COMM_PARENT, respectively. And it is legal to change any of these names with calls to MPI_Comm_set_name. yes you can rename MPI_COMM_WORLD. main character energy honestly 👑

Names passed in C must include the null terminator, and can be of maximum length MPI_MAX_OBJECT_NAME (including the null terminator). Names passed in Fortran can also have a maximum length of MPI_MAX_OBJECT_NAME. like, that's the ceiling. respect the ceiling 🚫

Setting a name on a communicator that already has a name associated with it replaces the old name. out with the old, in with the new 💅

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😭 ERRORS 😭

If an error occurs in an MPI function, the current MPI error handler is called to handle it. By default, this error handler aborts the MPI job. like, full on. no warning. just gone 💀

The error handler may be changed with MPI_Errhandler_set; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned (in C and Fortran; this error handler is less useful in with the C++ MPI bindings. The predefined error handler MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value needs to be recovered). Note that MPI does not guarantee that an MPI program can continue past an error. fr fr, that's a real caveat.

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. The C++ bindings for MPI do not return error values; instead, error values are communicated by throwing exceptions of type MPI::Exception (but not by default). Exceptions are only thrown if the error value is not MPI::SUCCESS.

⚠️ Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI functions will return upon an error, there will be no way to recover what the actual error value was. the info is just... gone. rip 🪦

• MPI_SUCCESS — No error; MPI routine completed successfully. slay! ✅
• MPI_ERR_COMM — Invalid communicator. A common error is to use a null communicator in a call (not even allowed in MPI_Comm_rank). like, don't do that 🙈
• MPI_ERR_ARG — Invalid argument. Some argument is invalid and is not identified by a specific error class. This is typically a NULL pointer or other such error.

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🌈 SEE ALSO 🌈

• MPI_Comm_get_name
• MPI_Type_get_name
• MPI_Type_set_name
• MPI_Win_get_name
• MPI_Win_set_name

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👑 MORE INFORMATION 👑

For more information, please see the official MPI Forum web site, which contains the text of both the MPI-1 and MPI-2 standards. These documents contain detailed information about each MPI function (most of which is not duplicated in these man pages).

http://www.mpi-forum.org/

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🍓 LOCATION 🍓

csetname.c

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and that's the whole page bestie 🫶 this was MPI_Comm_set_name(3) from LAM/MPI 7.1.4, dated 6/24/2006. oldie but a goodie. go name ur communicators, u deserve it 💖✨🎀