MPI_T_CVAR_HANDLE_ALLOC(3)			     Open MPI				MPI_T_CVAR_HANDLE_ALLOC(3)

MPI_T_cvar_handle_alloc, MPI_T_cvar_handle_free <#mpi-t-cvar-handle-free> - Allocate/free control variable handles

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)

DESCRIPTION
       MPI_T_cvar_handle_alloc	binds  the control variable specified in cvar_index to the MPI object specified in
       obj_handle. If MPI_T_cvar_get_info <#mpi-t-cvar-get-info> returns MPI_T_BIND_NO_OBJECT as  the  binding	of
       the  variable the obj_handle argument is ignored. The number of values represented by this control variable
       is returned in the count parameter. If the control variable represents a string	then  count  will  be  the
       maximum length of the string.

       MPI_T_cvar_handle_free  <#mpi-t-cvar-handle-free>  frees	 a handle allocated by MPI_T_cvar_handle_alloc and
       sets the handle argument to MPI_T_CVAR_HANDLE_NULL.

NOTES
       Open MPI does not currently support binding MPI objects to control variables so the obj_handle argument	is
       always ignored.

ERRORS
       MPI_T_cvar_handle_alloc will fail if:

       • MPI_T_ERR_NOT_INITIALIZED: The MPI Tools interface not initialized

       • MPI_T_ERR_INVALID_INDEX: The control variable index is invalid

       • MPI_T_ERR_OUT_OF_HANDLES: No more handles available

       MPI_T_cvar_handle_free <#mpi-t-cvar-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

       See also:

	  • MPI_T_cvar_get_info <#mpi-t-cvar-get-info>

Copyright
       2003-2026, The Open MPI Community

						   Mar 05, 2026				MPI_T_CVAR_HANDLE_ALLOC(3)
