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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
53 #include "gromacs/gpu_utils/gpueventsynchronizer.h"
54 #include "gromacs/mdlib/leapfrog_gpu.h"
55 #include "gromacs/mdlib/lincs_gpu.h"
56 #include "gromacs/mdlib/settle_gpu.h"
57 #include "gromacs/mdlib/update_constrain_gpu.h"
58 #include "gromacs/mdtypes/inputrec.h"
60 class GpuEventSynchronizer;
65 /*! \internal \brief Class with interfaces and data for GPU version of Update-Constraint. */
66 class UpdateConstrainGpu::Impl
70 /*! \brief Create Update-Constrain object.
72 * The constructor is given a non-nullptr \p deviceStream, in which all the update and constrain
73 * routines are executed.
75 * \param[in] ir Input record data: LINCS takes number of iterations and order of
77 * \param[in] mtop Topology of the system: SETTLE gets the masses for O and H atoms
78 * and target O-H and H-H distances from this object.
79 * \param[in] numTempScaleValues Number of temperature scaling groups. Set zero for no temperature coupling.
80 * \param[in] deviceContext GPU device context.
81 * \param[in] deviceStream GPU stream to use.
82 * \param[in] wcycle The wallclock counter
84 Impl(const t_inputrec& ir,
85 const gmx_mtop_t& mtop,
86 int numTempScaleValues,
87 const DeviceContext& deviceContext,
88 const DeviceStream& deviceStream,
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.
151 void set(DeviceBuffer<Float3> d_x,
152 DeviceBuffer<Float3> d_v,
153 DeviceBuffer<Float3> d_f,
154 const InteractionDefinitions& idef,
155 const t_mdatoms& md);
160 * Converts PBC data from t_pbc into the PbcAiuc format and stores the latter.
162 * \param[in] pbcType The type of the periodic boundary.
163 * \param[in] box The periodic boundary box matrix.
165 void setPbc(PbcType pbcType, const matrix box);
167 /*! \brief Return the synchronizer associated with the event indicated that the coordinates are ready on the device.
169 GpuEventSynchronizer* xUpdatedOnDeviceEvent();
172 * Returns whether the maximum number of coupled constraints is supported
173 * by the GPU LINCS code.
175 * \param[in] mtop The molecular topology
177 static bool isNumCoupledConstraintsSupported(const gmx_mtop_t& mtop);
180 //! GPU context object
181 const DeviceContext& deviceContext_;
183 const DeviceStream& deviceStream_;
184 //! GPU kernel launch config
185 KernelLaunchConfig coordinateScalingKernelLaunchConfig_;
187 //! Periodic boundary data
193 //! Local copy of the pointer to the device positions buffer
194 DeviceBuffer<Float3> d_x_;
195 //! Local copy of the pointer to the device velocities buffer
196 DeviceBuffer<Float3> d_v_;
197 //! Local copy of the pointer to the device forces buffer
198 DeviceBuffer<Float3> d_f_;
200 //! Device buffer for intermediate positions (maintained internally)
201 DeviceBuffer<Float3> d_xp_;
202 //! Number of elements in shifted coordinates buffer
204 //! Allocation size for the shifted coordinates buffer
205 int numXpAlloc_ = -1;
208 //! 1/mass for all atoms (GPU)
209 DeviceBuffer<real> d_inverseMasses_;
210 //! Number of elements in reciprocal masses buffer
211 int numInverseMasses_ = -1;
212 //! Allocation size for the reciprocal masses buffer
213 int numInverseMassesAlloc_ = -1;
215 //! Leap-Frog integrator
216 std::unique_ptr<LeapFrogGpu> integrator_;
217 //! LINCS GPU object to use for non-water constraints
218 std::unique_ptr<LincsGpu> lincsGpu_;
219 //! SETTLE GPU object for water constrains
220 std::unique_ptr<SettleGpu> settleGpu_;
222 //! The event to indicate when the update of coordinates is complete
223 GpuEventSynchronizer xUpdatedOnDeviceEvent_;
224 //! The wallclock counter
225 gmx_wallcycle* wcycle_ = nullptr;
230 #endif // GMX_MDLIB_UPDATE_CONSTRAIN_GPU_IMPL_H