src/gromacs/utility/init.h

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  35 /*! \file
  36  * \brief
  37  * Declares functions for initializing the \Gromacs library.
  38  *
  39  * Currently, only MPI initialization/finalization management is
  40  * required, and only if external MPI support is enabled.
  41  *
  42  * If MPI is already initialized, we should not call MPI_Init() or
  43  * MPI_Finalize(). This management object permits \Gromacs test code to
  44  * nest calls to functions that might normally implement a stand-alone
  45  * MPI-using tool. It also permits \Gromacs code to be called from code
  46  * that has already initialized MPI and needs that environment to work
  47  * and persist after \Gromacs code returns (e.g. \Gromacs tests,
  48  * external libraries that call \Gromacs code).
  49  *
  50  * It does so by maintaining a counter of the number of MPI
  51  * initializations, and only calling MPI_Init() or MPI_Finalize when
  52  * it is safe (ie. when the counter is at zero).
  53  *
  54  * Thread-MPI initialization and finalization for mdrun is all managed
  55  * in runner.c.
  56  *
  57  * \author Teemu Murtola <teemu.murtola@gmail.com>
  58  * \inpublicapi
  59  * \ingroup module_utility
  60  */
  61 #ifndef GMX_UTILITY_INIT_H
  62 #define GMX_UTILITY_INIT_H
  63
  64 namespace gmx
  65 {
  66
  67 /*! \brief
  68  * Initializes the \Gromacs library.
  69  *
  70  * \param[in] argc  argc value passed to main().
  71  * \param[in] argv  argv array passed to main().
  72  *
  73  * \p argc and \p argv are the command line arguments passed to main().
  74  * They are allowed to be NULL if \Gromacs is not compiled with MPI, MPI_Init()
  75  * has already been called, or if the MPI library \Gromacs is compiled against
  76  * allows it.
  77  *
  78  * Does not throw.
  79  *
  80  * \ingroup module_utility
  81  */
  82 void init(int *argc, char ***argv);
  83 /*! \brief
  84  * Deinitializes the \Gromacs library.
  85  *
  86  * Decrements the initialization counter, and calls MPI_Finalize()
  87  * if \Gromacs is compiled with MPI support and the counter has
  88  * reached zero.  In that case, it is not possible to reinitialize
  89  * \Gromacs after calling this function.  Instead, call gmx::init() at
  90  * a higher level, and note that calls to init can be nested safely.
  91  *
  92  * \ingroup module_utility
  93  */
  94 void finalize();
  95
  96 } // namespace gmx
  97
  98 #endif