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35 #ifndef GROMACS_SIMULATIONCONTEXT_H
36 #define GROMACS_SIMULATIONCONTEXT_H
40 * \brief Provide ways for client code to own simulation resources.
42 * For `gmx mdrun` to be implemented as a client program, public API needs to
43 * provide a way to create and manipulate the SimulationContext.
45 * \author M. Eric Irrgang <ericirrgang@gmail.com>
46 * \ingroup module_mdrun
53 #include "gromacs/mdrunutility/multisim.h"
54 #include "gromacs/utility/gmxmpi.h"
56 struct gmx_multisim_t;
66 * \brief Simulation environment and configuration.
68 * SimulationContext allows a simulation module (\relates gmx::mdrun) to retrieve
69 * runtime parameters and resources from client code. The client retains ownership
70 * of the context and its resources, with exceptions as noted.
72 * A client must share ownership of some resources and transfer ownership of
73 * other resources to create or configure the context. The simulation may in
74 * turn consume or borrow some resources from the context. This is a new
75 * framework that will evolve in the contexts of
76 * https://redmine.gromacs.org/issues/2375
77 * https://redmine.gromacs.org/issues/2587
79 * The public interface of SimulationContext is not yet well-specified.
80 * Client code can create an instance with gmx::createSimulationContext()
82 * \todo This class should also handle aspects of simulation
83 * environment such as working directory and environment variables.
85 * \ingroup module_mdrun
89 * This is a minimal placeholder for a more complete implementation.
90 * Interfaces for different API levels are not yet final.
91 * \todo Impose sensible access restrictions.
92 * Either the SimulationContext should be passed to the Mdrunner as logically constant or
93 * a separate handle class can provide access to resources that have been
94 * allocated by (negotiated with) the client for the current simulation
95 * (or simulation segment).
96 * Non-const accessors to shared resources need to be associated with update
97 * signals that the simulation components (modules and runner) can subscribe to.
99 * Also reference https://redmine.gromacs.org/issues/2587
101 class SimulationContext final
105 * \brief Object must be initialized with non-default constructor.
107 SimulationContext() = delete;
111 * \param communicator MPI communicator for this (set of) simulations
112 * \param multiSimDirectoryNames Names of any directories used with -multidir
114 explicit SimulationContext(MPI_Comm communicator, ArrayRef<const std::string> multiSimDirectoryNames);
117 * \brief MPI communicator object for this simulation object.
120 * the gmx wrapper binary has called MPI_Init, thus
121 * MPI_COMM_WORLD is now valid to use, and
122 * (in future) the gmxapi runner will handle such details
123 * (e.g. via mpi4py) before creating its SimulationContext.
124 * In both cases, if a multi-simulation is in use, then its
125 * communicator(s) are found in multiSimulation_. This
126 * communicator is that of all ranks from all simulations, and
127 * will later be split into one for each simulation.
128 * TODO Perhaps (for simplicity) that communicator splitting
129 * task can be undertaken during multi-sim setup.
131 * With thread-MPI in both cases, the communicator is set up later
132 * during the process of spawning the threads that will be the MPI
133 * ranks. (Multi-simulation is not supported with thread-MPI.)
135 MPI_Comm communicator_ = MPI_COMM_NULL;
138 * \brief Multi-sim handler (if required by e.g. gmx mdrun
139 * -multidir; only supported with real MPI)
141 std::unique_ptr<gmx_multisim_t> multiSimulation_;
145 } // end namespace gmx
147 #endif // GROMACS_SIMULATIONCONTEXT_H