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37 * \brief Declares GPU implementation class for update and constraints.
39 * This header file is needed to include from both the device-side
40 * kernels file, and the host-side management code.
42 * \author Artem Zhmurov <zhmurov@gmail.com>
44 * \ingroup module_mdlib
46 #ifndef GMX_MDLIB_UPDATE_CONSTRAIN_GPU_IMPL_H
47 #define GMX_MDLIB_UPDATE_CONSTRAIN_GPU_IMPL_H
51 #include "gromacs/gpu_utils/gpueventsynchronizer.cuh"
52 #include "gromacs/mdlib/leapfrog_gpu.h"
53 #include "gromacs/mdlib/lincs_gpu.cuh"
54 #include "gromacs/mdlib/settle_gpu.cuh"
55 #include "gromacs/mdlib/update_constrain_gpu.h"
56 #include "gromacs/mdtypes/inputrec.h"
61 /*! \internal \brief Class with interfaces and data for GPU version of Update-Constraint. */
62 class UpdateConstrainGpu::Impl
66 /*! \brief Create Update-Constrain object.
68 * The constructor is given a non-nullptr \p deviceStream, in which all the update and constrain
69 * routines are executed. \p xUpdatedOnDevice should mark the completion of all kernels that
70 * modify coordinates. The event is maintained outside this class and also passed to all (if
71 * any) consumers of the updated coordinates. The \p xUpdatedOnDevice also can not be a nullptr
72 * because the markEvent(...) method is called unconditionally.
74 * \param[in] ir Input record data: LINCS takes number of iterations and order of
76 * \param[in] mtop Topology of the system: SETTLE gets the masses for O and H atoms
77 * and target O-H and H-H distances from this object.
78 * \param[in] deviceContext GPU device context.
79 * \param[in] deviceStream GPU stream to use.
80 * \param[in] xUpdatedOnDevice The event synchronizer to use to mark that
81 * update is done on the GPU.
82 * \param[in] wcycle The wallclock counter
84 Impl(const t_inputrec& ir,
85 const gmx_mtop_t& mtop,
86 const DeviceContext& deviceContext,
87 const DeviceStream& deviceStream,
88 GpuEventSynchronizer* xUpdatedOnDevice,
89 gmx_wallcycle* wcycle);
95 * Integrates the equation of motion using Leap-Frog algorithm and applies
96 * LINCS and SETTLE constraints.
97 * If computeVirial is true, constraints virial is written at the provided pointer.
98 * doTempCouple should be true if:
99 * 1. The temperature coupling is enabled.
100 * 2. This is the temperature coupling step.
101 * Parameters virial/lambdas can be nullptr if computeVirial/doTempCouple are false.
103 * \param[in] fReadyOnDevice Event synchronizer indicating that the forces are ready in
105 * \param[in] dt Timestep.
106 * \param[in] updateVelocities If the velocities should be constrained.
107 * \param[in] computeVirial If virial should be updated.
108 * \param[out] virial Place to save virial tensor.
109 * \param[in] doTemperatureScaling If velocities should be scaled for temperature coupling.
110 * \param[in] tcstat Temperature coupling data.
111 * \param[in] doParrinelloRahman If current step is a Parrinello-Rahman pressure coupling step.
112 * \param[in] dtPressureCouple Period between pressure coupling steps.
113 * \param[in] prVelocityScalingMatrix Parrinello-Rahman velocity scaling matrix.
115 void integrate(GpuEventSynchronizer* fReadyOnDevice,
117 bool updateVelocities,
120 bool doTemperatureScaling,
121 gmx::ArrayRef<const t_grp_tcstat> tcstat,
122 bool doParrinelloRahman,
123 float dtPressureCouple,
124 const matrix prVelocityScalingMatrix);
126 /*! \brief Scale coordinates on the GPU for the pressure coupling.
128 * After pressure coupling step, the box size may change. Hence, the coordinates should be
129 * scaled so that all the particles fit in the new box.
131 * \param[in] scalingMatrix Coordinates scaling matrix.
133 void scaleCoordinates(const matrix scalingMatrix);
135 /*! \brief Scale velocities on the GPU for the pressure coupling.
137 * After pressure coupling step, the box size may change. In the C-Rescale algorithm, velocities should be scaled.
139 * \param[in] scalingMatrix Velocities scaling matrix.
141 void scaleVelocities(const matrix scalingMatrix);
143 /*! \brief Set the pointers and update data-structures (e.g. after NB search step).
145 * \param[in,out] d_x Device buffer with coordinates.
146 * \param[in,out] d_v Device buffer with velocities.
147 * \param[in] d_f Device buffer with forces.
148 * \param[in] idef System topology
149 * \param[in] md Atoms data.
150 * \param[in] numTempScaleValues Number of temperature scaling groups. Set zero for no temperature coupling.
152 void set(DeviceBuffer<RVec> d_x,
153 DeviceBuffer<RVec> d_v,
154 const DeviceBuffer<RVec> d_f,
155 const InteractionDefinitions& idef,
157 const int numTempScaleValues);
162 * Converts PBC data from t_pbc into the PbcAiuc format and stores the latter.
164 * \param[in] pbcType The type of the periodic boundary.
165 * \param[in] box The periodic boundary box matrix.
167 void setPbc(PbcType pbcType, const matrix box);
169 /*! \brief Return the synchronizer associated with the event indicated that the coordinates are ready on the device.
171 GpuEventSynchronizer* getCoordinatesReadySync();
174 * Returns whether the maximum number of coupled constraints is supported
175 * by the GPU LINCS code.
177 * \param[in] mtop The molecular topology
179 static bool isNumCoupledConstraintsSupported(const gmx_mtop_t& mtop);
182 //! GPU context object
183 const DeviceContext& deviceContext_;
185 const DeviceStream& deviceStream_;
186 //! GPU kernel launch config
187 KernelLaunchConfig coordinateScalingKernelLaunchConfig_;
189 //! Periodic boundary data
195 //! Local copy of the pointer to the device positions buffer
197 //! Local copy of the pointer to the device velocities buffer
199 //! Local copy of the pointer to the device forces buffer
202 //! Device buffer for intermediate positions (maintained internally)
204 //! Number of elements in shifted coordinates buffer
206 //! Allocation size for the shifted coordinates buffer
207 int numXpAlloc_ = -1;
210 //! 1/mass for all atoms (GPU)
211 real* d_inverseMasses_;
212 //! Number of elements in reciprocal masses buffer
213 int numInverseMasses_ = -1;
214 //! Allocation size for the reciprocal masses buffer
215 int numInverseMassesAlloc_ = -1;
217 //! Leap-Frog integrator
218 std::unique_ptr<LeapFrogGpu> integrator_;
219 //! LINCS GPU object to use for non-water constraints
220 std::unique_ptr<LincsGpu> lincsGpu_;
221 //! SETTLE GPU object for water constrains
222 std::unique_ptr<SettleGpu> settleGpu_;
224 //! An pointer to the event to indicate when the update of coordinates is complete
225 GpuEventSynchronizer* coordinatesReady_;
226 //! The wallclock counter
227 gmx_wallcycle* wcycle_ = nullptr;
232 #endif // GMX_MDLIB_UPDATE_CONSTRAIN_GPU_IMPL_H