MPI_T_PVAR_HANDLE_FREE(3)

💖 MPI_T_PVAR_HANDLE_FREE(3) 💖

okay bestie, we're in the Open MPI corner of the universe today — this is the manual page for MPI_T_pvar_handle_alloc / MPI_T_pvar_handle_free, and yes it's a whole mouthful, we love that for us 💅

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✨ NAME ✨

MPI_T_pvar_handle_alloc, MPI_T_pvar_handle_free — allocate/free MPI performance variable handles 🎀

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🌸 SYNOPSIS 🌸

🦋 C Syntax

#include <mpi.h>

int MPI_T_pvar_handle_alloc(int session, int pvar_index, void *obj_handle,
                            MPI_T_pvar_handle *handle, int *count)

int MPI_T_pvar_handle_free(int session, MPI_T_pvar_handle *handle)

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👑 DESCRIPTION 👑

so, MPI_T_pvar_handle_alloc does the cute little matchmaking thing: it binds the performance variable you name in pvar_index to the MPI object you name in obj_handle, inside the session identified by the session parameter. lowkey iconic 🌈

the object gets passed in the obj_handle argument as an address to a local variable that stores the object's handle. and here's the vibe check: if MPI_T_pvar_get_info returns MPI_T_BIND_NO_OBJECT as the binding for the variable, then the obj_handle argument is straight-up ignored 🙈 (not its fault, it's just not needed).

the handle you get back — the one that references the variable — is returned in the handle argument. and upon successful return, count contains the number of elements used to represent this variable (of the datatype that a previous MPI_T_pvar_get_info call gave you). periodt ✨

now, the value of pvar_index should be in the range 0 to num_pvar - 1, where num_pvar is the number of available performance variables as determined from a prior call to MPI_T_pvar_get_num. don't freestyle outside that range, bestie 😭 and the type of the MPI object it references must be consistent with the type returned in the bind argument in a prior call to MPI_T_pvar_get_info. consistency is the whole vibe.

then MPI_T_pvar_handle_free does the cleanup slay: it frees a handle allocated by MPI_T_pvar_handle_alloc and sets the handle argument to MPI_T_PVAR_HANDLE_NULL. tidy, responsible, main character energy 🫶

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💀 ERRORS 💀

MPI_T_pvar_handle_alloc will fail if:

• MPI_T_ERR_NOT_INITIALIZED: The MPI Tools interface not initialized 😴
• MPI_T_ERR_INVALID_INDEX: The performance variable index is invalid 🚫
• MPI_T_ERR_OUT_OF_HANDLES: No more handles available 💀

MPI_T_pvar_handle_free will fail if:

• MPI_T_ERR_NOT_INITIALIZED: The MPI Tools interface not initialized 😴
• MPI_T_ERR_INVALID_HANDLE: The handle is invalid or the handle argument passed in is not associated with the session argument 🙃

ngl, that second one is the classic "these two are not together, ma'am" moment — the handle and the session have to actually match 💔

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🔥 SEE ALSO 🔥

• MPI_T_pvar_get_info
• MPI_T_pvar_get_num

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🎀 COPYRIGHT 🎀

2003-2026, The Open MPI Community

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and that's the whole page, bestie — no cap, you ate that 🍓 go forth and manage your performance variable handles responsibly 💜✨

mwah 💋 — signed off on Sep 11, 2026, from the MPI_T_PVAR_HANDLE_FREE(3) chapter of the Open MPI saga 🌸🦋