Fix stop condition handling (modular simulator)

[gromacs.git] / src / gromacs / modularsimulator / signallers.h

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 * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
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/*! \libinternal
 * \brief Declares the signallers for the modular simulator
 *
 * \author Pascal Merz <pascal.merz@me.com>
 * \ingroup module_modularsimulator
 */

#ifndef GMX_MODULARSIMULATOR_SIGNALLERS_H
#define GMX_MODULARSIMULATOR_SIGNALLERS_H

#include <vector>

#include "gromacs/compat/pointers.h"

#include "modularsimulatorinterfaces.h"

namespace gmx
{
class StopHandler;
class TrajectoryElement;

//! \addtogroup module_modularsimulator
//! \{

/*! \libinternal
 * \brief Builder for signallers
 *
 * This builder allows clients to register, and then builds the signaller
 * passing on the list of clients.
 *
 * @tparam Signaller  The signaller to be built
 */
template <typename Signaller>
class SignallerBuilder final
{
    public:
        //! Allows clients to register to the signaller
        void registerSignallerClient(
            compat::not_null<typename Signaller::Client*> client);

        //! Build the signaller
        template <typename ... Args>
        std::unique_ptr<Signaller> build(Args && ... args);

    private:
        //! List of signaller clients
        std::vector<typename Signaller::Client*> signallerClients_;

        //! Helper function to get the callbacks from the clients
        template <typename ... Args>
        std::vector<SignallerCallbackPtr> buildCallbackVector(Args && ... args);

        /*! \brief Get a callback from a single client
         *
         * This is in a separate function, as the exact call depends on the
         * specific signaller / client.
         */
        template <typename ... Args>
        SignallerCallbackPtr getSignallerCallback(
            typename Signaller::Client *client,
            Args && ... args);

};

/*! \libinternal
 * \brief Element signalling a neighbor search step
 *
 * This element informs its clients via callbacks
 * when a neighbor-searching step is happening.
 */
class NeighborSearchSignaller final :
    public                    ISignaller
{
    public:
        /*! \brief Run the signaller at a specific step / time
         *
         * Informs callbacks if step % nstlist_ == 0
         *
         * @param step  The current time step
         * @param time  The current time
         */
        void signal(Step step, Time time) override;

        //! Do nothing at setup time
        void signallerSetup() override {};

        //! Allow builder to construct
        friend class SignallerBuilder<NeighborSearchSignaller>;
        //! Define client type
        typedef INeighborSearchSignallerClient Client;

    private:
        /*! \brief Constructor
         *
         * @param callbacks  A vector of pointers to callbacks
         * @param nstlist    The frequency at which neighbor search is performed
         * @param initStep   The first step of the simulation
         * @param initTime   The start time of the simulation
         */
        NeighborSearchSignaller(
            std::vector<SignallerCallbackPtr> callbacks,
            Step nstlist, Step initStep, Time initTime);

        //! Client callbacks
        std::vector<SignallerCallbackPtr> callbacks_;

        //! The NS frequency
        const Step nstlist_;
        //! The initial step of the simulation
        const Step initStep_;
        //! The initial time of the simulation
        const Time initTime_;
};

/*! \libinternal
 * \brief Element signalling the last step
 *
 * This element informs its clients via callbacks
 * when the last step is happening.
 */
class LastStepSignaller final :
    public              ISignaller,
    public              INeighborSearchSignallerClient
{
    public:
        /*! \brief Run the signaller at a specific step / time
         *
         * Informs callbacks if this is the last step
         *
         * @param step  The current time step
         * @param time  The current time
         */
        void signal(Step step, Time time) override;

        //! Check that necessary registration was done
        void signallerSetup() override;

        //! Allow builder to construct
        friend class SignallerBuilder<LastStepSignaller>;
        //! Define client type
        typedef ILastStepSignallerClient Client;

    private:
        /*! \brief Constructor
         *
         * @param callbacks    A vector of pointers to callbacks
         * @param nsteps       The total number of steps for the simulation
         * @param initStep     The first step of the simulation
         * @param stopHandler  A pointer to the stop handler (LastStepSignaller takes ownership)
         */
        LastStepSignaller(
            std::vector<SignallerCallbackPtr> callbacks,
            Step nsteps, Step initStep,
            StopHandler* stopHandler);

        //! Client callbacks
        std::vector<SignallerCallbackPtr> callbacks_;

        //! The last step of the simulation
        const Step   stopStep_;
        //! Whether we signalled last step due to stop condition
        bool         signalledStopCondition_;
        //! A pointer to the stop handler communicating signal and time-related stops
        StopHandler *stopHandler_;

        //! INeighborSearchSignallerClient implementation
        SignallerCallbackPtr registerNSCallback() override;
        //! The next NS step (notified by NS signaller)
        Step nextNSStep_;
        //! Whether we registered to the NS signaller
        bool nsStepRegistrationDone_;
};

/*! \libinternal
 * \brief Element signalling a logging step
 *
 * This element informs its clients via callbacks
 * when a logging step is happening.
 */
class LoggingSignaller final :
    public             ISignaller,
    public             ILastStepSignallerClient
{
    public:
        /*! \brief Run the signaller at a specific step / time
         *
         * Informs callbacks if step % nstlog_ == 0
         *
         * @param step  The current time step
         * @param time  The current time
         */
        void signal(Step step, Time time) override;

        //! Check that necessary registration was done
        void signallerSetup() override;

        //! Allow builder to construct
        friend class SignallerBuilder<LoggingSignaller>;
        //! Define client type
        typedef ILoggingSignallerClient Client;

    private:
        /*! \brief Constructor
         *
         * @param callbacks  A vector of pointers to callbacks
         * @param nstlog     The logging frequency
         * @param initStep   The first step of the simulation
         * @param initTime   The start time of the simulation
         */
        LoggingSignaller(
            std::vector<SignallerCallbackPtr> callbacks,
            Step                         nstlog,
            Step                         initStep,
            Time                         initTime);

        //! Client callbacks
        std::vector<SignallerCallbackPtr> callbacks_;

        //! The logging frequency
        const Step nstlog_;
        //! The initial step of the simulation
        const Step initStep_;
        //! The initial time of the simulation
        const Time initTime_;

        //! ILastStepSignallerClient implementation
        SignallerCallbackPtr registerLastStepCallback() override;
        //! The last step (notified by signaller)
        Step lastStep_;
        //! Whether we registered to the last step signaller
        bool lastStepRegistrationDone_;
};

/*! \libinternal
 * \brief Element signalling energy related special steps
 *
 * This element informs its clients via callbacks
 * of the following events:
 *   - energy calculation step
 *   - virial calculation step
 *   - free energy calculation step
 */
class EnergySignaller final :
    public            ISignaller,
    public            ITrajectorySignallerClient,
    public            ILoggingSignallerClient
{
    public:
        /*! \brief Run the signaller at a specific step / time
         *
         * Informs callbacks of energy / virial / free energy special steps
         *
         * @param step  The current time step
         * @param time  The current time
         */
        void signal(Step step, Time time) override;

        //! Check that necessary registration was done
        void signallerSetup() override;

        //! Allow builder to construct
        friend class SignallerBuilder<EnergySignaller>;
        //! Define client type
        typedef IEnergySignallerClient Client;

    private:
        /*! \brief Constructor
         *
         * @param calculateEnergyCallbacks      A vector of pointers to callbacks (energy steps)
         * @param calculateVirialCallbacks      A vector of pointers to callbacks (virial steps)
         * @param calculateFreeEnergyCallbacks  A vector of pointers to callbacks (free energy steps)
         * @param nstcalcenergy                 The energy calculation frequency
         * @param nstcalcfreeenergy             The free energy calculation frequency
         * @param nstcalcvirial                 The free energy calculation frequency
         */
        EnergySignaller(
            std::vector<SignallerCallbackPtr> calculateEnergyCallbacks,
            std::vector<SignallerCallbackPtr> calculateVirialCallbacks,
            std::vector<SignallerCallbackPtr> calculateFreeEnergyCallbacks,
            int                               nstcalcenergy,
            int                               nstcalcfreeenergy,
            int                               nstcalcvirial);

        //! Client callbacks
        //! {
        std::vector<SignallerCallbackPtr> calculateEnergyCallbacks_;
        std::vector<SignallerCallbackPtr> calculateVirialCallbacks_;
        std::vector<SignallerCallbackPtr> calculateFreeEnergyCallbacks_;
        //! }

        //! The energy calculation frequency
        const int nstcalcenergy_;
        //! The free energy calculation frequency
        const int nstcalcfreeenergy_;
        //! The virial calculation frequency
        const int nstcalcvirial_;

        //! ITrajectorySignallerClient implementation
        SignallerCallbackPtr registerTrajectorySignallerCallback(TrajectoryEvent event) override;
        //! The energy writing step (notified by signaller)
        Step energyWritingStep_;
        //! Whether we registered to the trajectory signaller
        bool trajectoryRegistrationDone_;

        //! ILoggingSignallerClient implementation
        SignallerCallbackPtr registerLoggingCallback() override;
        //! The next logging step (notified by signaller)
        Step loggingStep_;
        //! Whether we registered to the logging signaller
        bool loggingRegistrationDone_;
};

//! /}

//! Allows clients to register to the signaller
template <class Signaller>
void SignallerBuilder<Signaller>::registerSignallerClient(
        compat::not_null<typename Signaller::Client*> client)
{
    signallerClients_.emplace_back(client);
}

/*! \brief Build the signaller
 *
 * General version - for NeighborSearchSignaller, LastStepSignaller, LoggingSignaller
 */
template <class Signaller>
template <typename ... Args>
std::unique_ptr<Signaller> SignallerBuilder<Signaller>::build(Args && ... args)
{
    auto callbacks = buildCallbackVector();
    // NOLINTNEXTLINE(modernize-make-unique): make_unique does not work with private constructor
    return std::unique_ptr<Signaller>(
            new Signaller(
                    std::move(callbacks),
                    std::forward<Args>(args) ...));
}

/*! \brief Build the signaller
 *
 * Specialized version - EnergySignaller has a significantly different build process
 */
template <>
template <typename ... Args>
std::unique_ptr<EnergySignaller> SignallerBuilder<EnergySignaller>::build(Args && ... args)
{
    auto calculateEnergyCallbacks     = buildCallbackVector(EnergySignallerEvent::energyCalculationStep);
    auto calculateVirialCallbacks     = buildCallbackVector(EnergySignallerEvent::virialCalculationStep);
    auto calculateFreeEnergyCallbacks = buildCallbackVector(EnergySignallerEvent::freeEnergyCalculationStep);
    // NOLINTNEXTLINE(modernize-make-unique): make_unique does not work with private constructor
    return std::unique_ptr<EnergySignaller>(
            new EnergySignaller(
                    std::move(calculateEnergyCallbacks),
                    std::move(calculateVirialCallbacks),
                    std::move(calculateFreeEnergyCallbacks),
                    std::forward<Args>(args) ...));
}

//! Helper function to get the callbacks from the clients
template <typename Signaller>
template <typename ... Args>
std::vector<SignallerCallbackPtr> SignallerBuilder<Signaller>::buildCallbackVector(Args && ... args)
{
    std::vector<SignallerCallbackPtr> callbacks;
    // Allow clients to register their callbacks
    for (auto &client : signallerClients_)
    {
        if (auto callback = getSignallerCallback(client, std::forward<Args>(args) ...))  // don't register nullptr
        {
            callbacks.emplace_back(std::move(callback));
        }
    }
    return callbacks;
}

//! Get a callback from a single client - NeighborSearchSignaller
template <>
template <typename ... Args>
SignallerCallbackPtr SignallerBuilder<NeighborSearchSignaller>::getSignallerCallback(
        typename NeighborSearchSignaller::Client *client, Args && ... args)
{
    return client->registerNSCallback(std::forward<Args>(args) ...);
}

//! Get a callback from a single client - LastStepSignaller
template <>
template <typename ... Args>
SignallerCallbackPtr SignallerBuilder<LastStepSignaller>::getSignallerCallback(
        typename LastStepSignaller::Client *client, Args && ... args)
{
    return client->registerLastStepCallback(std::forward<Args>(args) ...);
}

//! Get a callback from a single client - LoggingSignaller
template <>
template <typename ... Args>
SignallerCallbackPtr SignallerBuilder<LoggingSignaller>::getSignallerCallback(
        typename LoggingSignaller::Client *client, Args && ... args)
{
    return client->registerLoggingCallback(std::forward<Args>(args) ...);
}

//! Get a callback from a single client - EnergySignaller
template <>
template <typename ... Args>
SignallerCallbackPtr SignallerBuilder<EnergySignaller>::getSignallerCallback(
        typename EnergySignaller::Client *client, Args && ... args)
{
    return client->registerEnergyCallback(std::forward<Args>(args) ...);
}

}      // namespace gmx

#endif // GMX_MODULARSIMULATOR_SIGNALLERS_H