src/gromacs/mdlib/update_constrain_gpu.h

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  35 /*! \libinternal \file
  36  *
  37  * \brief Declaration of high-level functions of GPU implementation of update and constrain class.
  38  *
  39  * \author Artem Zhmurov <zhmurov@gmail.com>
  40  *
  41  * \ingroup module_mdlib
  42  * \inlibraryapi
  43  */
  44 #ifndef GMX_MDLIB_UPDATE_CONSTRAIN_GPU_H
  45 #define GMX_MDLIB_UPDATE_CONSTRAIN_GPU_H
  46
  47 #include "gromacs/gpu_utils/devicebuffer_datatype.h"
  48 #include "gromacs/mdtypes/group.h"
  49 #include "gromacs/timing/wallcycle.h"
  50 #include "gromacs/utility/arrayref.h"
  51 #include "gromacs/utility/classhelpers.h"
  52
  53 class DeviceContext;
  54 class DeviceStream;
  55 class GpuEventSynchronizer;
  56 struct gmx_mtop_t;
  57 enum class PbcType : int;
  58 class InteractionDefinitions;
  59 struct t_inputrec;
  60 struct t_mdatoms;
  61 struct t_pbc;
  62
  63 namespace gmx
  64 {
  65
  66 class UpdateConstrainGpu
  67 {
  68
  69 public:
  70     /*! \brief Create Update-Constrain object.
  71      *
  72      * The constructor is given a non-nullptr \p deviceStream, in which all the update and constrain
  73      * routines are executed. \p xUpdatedOnDevice should mark the completion of all kernels that
  74      * modify coordinates. The event is maintained outside this class and also passed to all (if
  75      * any) consumers of the updated coordinates. The \p xUpdatedOnDevice also can not be a nullptr
  76      * because the markEvent(...) method is called unconditionally.
  77      *
  78      * \param[in] ir                Input record data: LINCS takes number of iterations and order of
  79      *                              projection from it.
  80      * \param[in] mtop              Topology of the system: SETTLE gets the masses for O and H atoms
  81      *                              and target O-H and H-H distances from this object.
  82      * \param[in] deviceContext     GPU device context.
  83      * \param[in] deviceStream      GPU stream to use.
  84      * \param[in] xUpdatedOnDevice  The event synchronizer to use to mark that update is done
  85      *                              on the GPU.
  86      * \param[in] wcycle            The wallclock counter
  87      */
  88     UpdateConstrainGpu(const t_inputrec&     ir,
  89                        const gmx_mtop_t&     mtop,
  90                        const DeviceContext&  deviceContext,
  91                        const DeviceStream&   deviceStream,
  92                        GpuEventSynchronizer* xUpdatedOnDevice,
  93                        gmx_wallcycle*        wcycle);
  94
  95     ~UpdateConstrainGpu();
  96
  97     /*! \brief Integrate
  98      *
  99      * This will extract temperature scaling factors from tcstat, transform them into the plain
 100      * array and call the normal integrate method.
 101      *
 102      * \param[in]  fReadyOnDevice           Event synchronizer indicating that the forces are
 103      *                                      ready in the device memory.
 104      * \param[in]  dt                       Timestep.
 105      * \param[in]  updateVelocities         If the velocities should be constrained.
 106      * \param[in]  computeVirial            If virial should be updated.
 107      * \param[out] virial                   Place to save virial tensor.
 108      * \param[in]  doTemperatureScaling     If velocities should be scaled for temperature coupling.
 109      * \param[in]  tcstat                   Temperature coupling data.
 110      * \param[in]  doParrinelloRahman       If current step is a Parrinello-Rahman pressure coupling step.
 111      * \param[in]  dtPressureCouple         Period between pressure coupling steps.
 112      * \param[in]  prVelocityScalingMatrix  Parrinello-Rahman velocity scaling matrix.
 113      */
 114     void integrate(GpuEventSynchronizer*             fReadyOnDevice,
 115                    real                              dt,
 116                    bool                              updateVelocities,
 117                    bool                              computeVirial,
 118                    tensor                            virial,
 119                    bool                              doTemperatureScaling,
 120                    gmx::ArrayRef<const t_grp_tcstat> tcstat,
 121                    bool                              doParrinelloRahman,
 122                    float                             dtPressureCouple,
 123                    const matrix                      prVelocityScalingMatrix);
 124
 125     /*! \brief Scale coordinates on the GPU for the pressure coupling.
 126      *
 127      * After pressure coupling step, the box size may change. Hence, the coordinates should be
 128      * scaled so that all the particles fit in the new box.
 129      *
 130      * \param[in] scalingMatrix Coordinates scaling matrix.
 131      */
 132     void scaleCoordinates(const matrix scalingMatrix);
 133
 134     /*! \brief Scale velocities on the GPU for the pressure coupling.
 135      *
 136      * After pressure coupling step, the box size may change. In the C-Rescale algorithm, velocities should be scaled.
 137      *
 138      * \param[in] scalingMatrix Velocities scaling matrix.
 139      */
 140     void scaleVelocities(const matrix scalingMatrix);
 141
 142     /*! \brief Set the pointers and update data-structures (e.g. after NB search step).
 143      *
 144      * \param[in,out]  d_x                 Device buffer with coordinates.
 145      * \param[in,out]  d_v                 Device buffer with velocities.
 146      * \param[in]      d_f                 Device buffer with forces.
 147      * \param[in]      idef                System topology
 148      * \param[in]      md                  Atoms data.
 149      * \param[in]      numTempScaleValues  Number of temperature scaling groups. Zero for no temperature scaling.
 150      */
 151     void set(DeviceBuffer<RVec>            d_x,
 152              DeviceBuffer<RVec>            d_v,
 153              DeviceBuffer<RVec>            d_f,
 154              const InteractionDefinitions& idef,
 155              const t_mdatoms&              md,
 156              int                           numTempScaleValues);
 157
 158     /*! \brief
 159      * Update PBC data.
 160      *
 161      * Converts PBC data from t_pbc into the PbcAiuc format and stores the latter.
 162      *
 163      * \param[in] pbcType The type of the periodic boundary (Xyz, NO, XY or Screw).
 164      * \param[in] box     The periodic boundary box matrix.
 165      */
 166     void setPbc(PbcType pbcType, const matrix box);
 167
 168     /*! \brief Return the synchronizer associated with the event indicated that the coordinates are ready on the device.
 169      */
 170     GpuEventSynchronizer* getCoordinatesReadySync();
 171
 172     /*! \brief
 173      * Returns whether the maximum number of coupled constraints is supported
 174      * by the GPU LINCS code.
 175      *
 176      * \param[in] mtop The molecular topology
 177      */
 178     static bool isNumCoupledConstraintsSupported(const gmx_mtop_t& mtop);
 179
 180 private:
 181     class Impl;
 182     gmx::PrivateImplPointer<Impl> impl_;
 183 };
 184
 185 } // namespace gmx
 186
 187 #endif // GMX_MDLIB_UPDATE_CONSTRAIN_GPU_H