Gromacs
2026.0-dev-20241113-4b16639
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#include <gromacs/mdrun/simulationcontext.h>
Simulation environment and configuration.
SimulationContext allows a simulation module () to retrieve runtime parameters and resources from client code. The client retains ownership of the context and its resources, with exceptions as noted.
A client must share ownership of some resources and transfer ownership of other resources to create or configure the context. The simulation may in turn consume or borrow some resources from the context. This is a new framework that will evolve in the contexts of https://gitlab.com/gromacs/gromacs/-/issues/2375 https://gitlab.com/gromacs/gromacs/-/issues/2587
The public interface of SimulationContext is not yet well-specified. Client code can create an instance with gmx::createSimulationContext()
This is a minimal placeholder for a more complete implementation. Interfaces for different API levels are not yet final.
Also reference https://gitlab.com/gromacs/gromacs/-/issues/2587
Public Member Functions | |
SimulationContext ()=delete | |
Object must be initialized with non-default constructor. | |
SimulationContext (MPI_Comm communicator, ArrayRef< const std::string > multiSimDirectoryNames) | |
Initialize from borrowed communicator. More... | |
Public Attributes | |
MPI_Comm | libraryWorldCommunicator_ = MPI_COMM_NULL |
MPI resources for the entire simulation context. More... | |
MPI_Comm | simulationCommunicator_ = MPI_COMM_NULL |
MPI communicator object for this simulation. More... | |
std::unique_ptr< gmx_multisim_t > | multiSimulation_ |
Multi-sim handler (if required by e.g. gmx mdrun -multidir; only supported with real MPI) More... | |
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explicit |
Initialize from borrowed communicator.
communicator | Communicator for all collaborating simulation processes. |
multiSimDirectoryNames | Names of any directories used with -multidir |
Caller is responsible for keeping communicator valid for the life of SimulationContext, and then freeing the communicator, if appropriate.
With an external MPI library (non-thread-MPI chosen when configuring with CMake), the client promises that MPI has been initialized (such as by calling gmx::init()). This communicator is "borrowed" (not duplicated) from the caller. Additional communicators may be split from the provided communicator during the life of the SimulationContext or its consumers.
With thread-MPI, communicator must be MPI_COMM_NULL. The communicator is set up later during the process of spawning the threads that will be the MPI ranks. (Multi-simulation is not supported with thread-MPI.)
MPI_Comm gmx::SimulationContext::libraryWorldCommunicator_ = MPI_COMM_NULL |
MPI resources for the entire simulation context.
With an external MPI library (non-thread-MPI chosen when configuring with CMake), gmx::init() has called MPI_Init and the provided communicator is valid to use. The communicator is "borrowed" (not duplicated) from the caller.
With thread-MPI, the communicator is set up later during the process of spawning the threads that will be the MPI ranks.
std::unique_ptr<gmx_multisim_t> gmx::SimulationContext::multiSimulation_ |
Multi-sim handler (if required by e.g. gmx mdrun -multidir; only supported with real MPI)
If a multi-simulation is in use, then its communicator(s) are found in multiSimulation_. This communicator is that of all ranks from all simulations, and will later be split into one for each simulation. TODO: Perhaps (for simplicity) communicator splitting can be undertaken during multi-sim setup (acquisition of the multisim resource).
Multi-simulation is not supported with thread-MPI.
MPI_Comm gmx::SimulationContext::simulationCommunicator_ = MPI_COMM_NULL |
MPI communicator object for this simulation.
With an external MPI library (non-thread-MPI chosen when configuring with CMake), gmx::init() has called MPI_Init and the provided communicator is valid to use. The communicator is "borrowed" (not duplicated) from the caller.
With thread-MPI, the communicator is set up later during the process of spawning the threads that will be the MPI ranks.