MPI_T_CVAR_HANDLE_FREE(3)

💖 MPI_T_CVAR_HANDLE_FREE 💖

okay bestie, welcome to MPI_T_CVAR_HANDLE_FREE(3) from the Open MPI manual, third section, no cap — this is where you learn to free a control variable handle you got from the alloc bestie. 🫶

MPI_T_cvar_handle_alloc, MPI_T_cvar_handle_free — allocate/free control variable handles ✨

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🌸 SYNTAX 🌸

✨ C Syntax ✨

#include <mpi.h>

int MPI_T_cvar_handle_alloc(int cvar_index, void *obj_handle,
                            MPI_T_cvar_handle *handle, int *count)

int MPI_T_cvar_handle_free(MPI_T_cvar_handle *handle)

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💅 DESCRIPTION 💅

okay so MPI_T_cvar_handle_alloc is the main character here: it binds the control variable you named in cvar_index to the MPI object you named in obj_handle. 🎀

literally though — if MPI_T_cvar_get_info handed you MPI_T_BIND_NO_OBJECT as the binding of that variable, then the obj_handle argument is just... ignored. it's giving "not invited to the party". 🙈

the number of values that this control variable represents comes back to you in the count parameter. and if the control variable is a string? then count is the maximum length of the string. periodt. 💅

then there's MPI_T_cvar_handle_free — she's the clean-up icon. she frees a handle that MPI_T_cvar_handle_alloc allocated, and she sets the handle argument to MPI_T_CVAR_HANDLE_NULL. iconic, tidy, no leftover mess. ✨

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📝 NOTES 📝

ngl, a lil tea: Open MPI does not currently support binding MPI objects to control variables, so the obj_handle argument is always ignored. fr fr. 🫠

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💀 ERRORS 💀

MPI_T_cvar_handle_alloc will fail if:

• MPI_T_ERR_NOT_INITIALIZED — the MPI Tools interface is not initialized 😭
• MPI_T_ERR_INVALID_INDEX — the control variable index is invalid 🚫
• MPI_T_ERR_OUT_OF_HANDLES — no more handles available, they're all taken 💀

MPI_T_cvar_handle_free will fail if:

• MPI_T_ERR_NOT_INITIALIZED — the MPI Tools interface is not initialized 😭
• MPI_T_ERR_INVALID_HANDLE — the handle is invalid 🚫

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🦋 See also 🦋

• MPI_T_cvar_get_info — she knows things, go say hi 👑

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Copyright 🌈

2003-2026, The Open MPI Community 💜

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okay and that's the whole page bestie, we ate and left no crumbs 🍓 — this was MPI_T_CVAR_HANDLE_FREE(3) from Open MPI, dated Sep 10, 2026, and you're officially a handle-freeing icon now. mwah 💋✨