MPI_T_PVAR_START(3)				     Open MPI				       MPI_T_PVAR_START(3)

MPI_T_pvar_start, MPI_T_pvar_stop <#mpi-t-pvar-stop> - Start/stop a performance variable

SYNTAX
   C Syntax
	  #include <mpi.h>

	  int MPI_T_pvar_start(MPI_T_pvar_session session, MPI_T_pvar_handle handle)

	  int MPI_T_pvar_stop(MPI_T_pvar_session session, MPI_T_pvar_handle handle)

INPUT PARAMETERS
       • session: Performance experiment session.

       • handle: Performance variable handle.

DESCRIPTION
       MPI_T_pvar_start	 starts	 the  performance  variable with the handle specified in handle. The special value
       MPI_T_PVAR_ALL_HANDLES can be passed in handle to start all non-continuous handles in the session specified
       in session.

       MPI_T_pvar_stop <#mpi-t-pvar-stop> stops the performance variable with the handle specified in handle.  The
       special	value  MPI_T_PVAR_ALL_HANDLES  can  be	passed in handle to stop all non-continuous handles in the
       session specified in session.

       Continuous performance variables can neither be started nor stopped.

ERRORS
       MPI_T_pvar_start and MPI_T_pvar_stop() will fail if:

       • MPI_T_ERR_NOT_INITIALIZED: The MPI Tools interface not initialized

       • MPI_T_ERR_INVALID_SESSION: Session parameter is not a valid session

       • MPI_T_ERR_INVALID_HANDLE: Invalid handle or handle not associated with the session

       • MPI_T_ERR_PVAR_NO_STARTSTOP: The variable cannot be started or stopped

       See also:

	  • MPI_T_pvar_get_info <#mpi-t-pvar-get-info>

Copyright
       2003-2026, The Open MPI Community

						   Mar 05, 2026				       MPI_T_PVAR_START(3)
