MPI_T_PVAR_HANDLE_ALLOC(3)

✨ MPI_T_pvar_handle_alloc, MPI_T_pvar_handle_free ✨

okay bestie, so this is the Open MPI manual page for MPI_T_pvar_handle_alloc(3) and its little sibling MPI_T_pvar_handle_free 💖 it's giving "allocate/free MPI performance variable handles" and honestly? kind of iconic.

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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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🦋 SYNTAX 🦋

💅 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 here's the tea ☕ MPI_T_pvar_handle_alloc binds the performance variable you named in pvar_index to the MPI object you named in obj_handle, all inside the session identified by the session parameter. The object comes in through the obj_handle argument as an address to a local variable that's holding the object's handle. And listen — if MPI_T_pvar_get_info hands back MPI_T_BIND_NO_OBJECT as the binding for that variable, then the obj_handle argument is just ignored, no thoughts, head empty 🙈. The handle you get to reference the variable comes back in the handle argument. And once it returns successfully, count contains the number of elements (of the datatype that a previous MPI_T_pvar_get_info call already told you about) used to represent this variable. slay 💅

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. And the type of the MPI object it references has to be consistent with the type returned in the bind argument from a prior call to MPI_T_pvar_get_info. no cap, check before you wreck 🫶

Then MPI_T_pvar_handle_free frees a handle that MPI_T_pvar_handle_alloc allocated, and it sets the handle argument to MPI_T_PVAR_HANDLE_NULL. clean up after yourself, queen 👑

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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 🙈

bestie if you're seeing MPI_T_ERR_NOT_INITIALIZED it's giving "you forgot to init the interface" energy, and MPI_T_ERR_OUT_OF_HANDLES means the handle supply said "I'm full, no more room in this club" 🎀

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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, periodt 💖 this was MPI_T_PVAR_HANDLE_ALLOC(3) from the Open MPI crew, dated Sep 10, 2026 — go forth and allocate responsibly, my love 🦋✨🎀