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//
//
// class description:
//   This is a class for run control in GEANT4 for multi-threaded runs
//   It extends G4RunManager re-implementing multi-threaded behavior in
//   key methods. See documentation for G4RunManager
//   Users initializes an instance of this class instead of G4RunManager
//   to start a multi-threaded simulation.

#ifndef G4MTRunManager_h
#define G4MTRunManager_h 1

#include "G4RunManager.hh"
#include "G4Threading.hh"
#include "G4RNGHelper.hh"
#include <list>
#include <map>

class G4MTRunManagerKernel;
class G4ScoringManager;
class G4UserWorkerInitialization;
class G4UserWorkerThreadInitialization;

//TODO: Split random number storage from this class

class G4MTRunManager : public G4RunManager {
public:
    G4MTRunManager();
    virtual ~G4MTRunManager();
    //New method
    void SetNumberOfThreads( G4int n );
    G4int GetNumberOfThreads() const { return nworkers; }
public:

    //Inherited methods to re-implement for MT case
    virtual void Initialize();
    virtual void InitializeEventLoop(G4int n_event, const char* macroFile=0, G4int n_select=-1);

    //The following do not do anything for this runmanager
    virtual void TerminateOneEvent();
    virtual void ProcessOneEvent(G4int i_event);
    virtual void TerminateEventLoop();
    virtual void ConstructScoringWorlds();
    virtual void InitializePhysics();
    virtual void RunTermination();

    //The following method should be invoked by G4WorkerRunManager for each event.
    //False is returned if no more event to be processed.
    // Note: G4Event object must be instantiated by a worker thread. In case no more
    //  event remains to be processed, that worker thread must delete that G4Event
    //  object.
    virtual G4bool SetUpAnEvent(G4Event*, long& s1, long& s2, long& s3);
    // Same as above method, but the seeds are set only once over "eventModulo" events.
    // The return value shows the number of events the caller Worker has to process
    // (between 1 and eventModulo depending on number of events yet to be processed).
    // G4Event object has the event ID of the first event of this bunch.
    // If zero is returned no more event needs to be processed, and worker thread 
    // must delete that G4Event.
    virtual G4int SetUpNEvents(G4Event*, G4SeedsQueue* seedsQueue);
    
    //Method called by Initialize() method
protected:
    //Initialize the seeds list, if derived class does not implement this method
    //A default generation will be used (nevents*2 random seeds)
    //Return true if initialization is done.
    virtual G4bool InitializeSeeds( G4int /*nevts*/) { return false; };
    //Adds one seed to the list of seeds
    virtual void PrepareCommandsStack();
    virtual void StoreRNGStatus(const G4String& filenamePrefix );
    virtual void CreateAndStartWorkers();
    //Creates worker threads and signal to start
public:
    std::vector<G4String> GetCommandStack();
    //This method is invoked just before spawning the threads to
    //collect from UI managere the list of commands that threads
    //will execute.
private:
    // Number of worker threads. To be set by SetNumberOfThreads() method.
    G4int nworkers;
    // Force to use this number regardless of SetNumberOfThreads() method.
    G4int forcedNwokers;

    //List of workers (i.e. thread)
    typedef std::list<G4Thread*> G4ThreadsList;
    G4ThreadsList threads;
    //List of workers run managers
    //List of all workers run managers
    std::vector<G4String> uiCmdsForWorkers;
    //List of UI commands for workers.
    CLHEP::HepRandomEngine* masterRNGEngine;
    //Pointer to the mastet thread random engine
protected:
    virtual void WaitForReadyWorkers();
    //Master thread barrier:
    //Call this function to block master thread and
    //wait workers to be ready to process work.
    //This function will return only when all
    //workers are ready to perform event loop.
    virtual void WaitForEndEventLoopWorkers();
    //Master thread barrier:
    //Call this function to block master thread and
    //wait workers have finished current event loop.
    //This function will return only when all
    //workers have finished processing events for this run.
protected:
    G4int numberOfEventToBeProcessed;
    virtual void TerminateWorkers();
    //Empty the workersList

public:
    virtual void ThisWorkerReady();
    //Worker threads barrier:
    //This method should be called by each
    //worker when ready to start thread event-loop
    //This method will return only when all workers
    //are ready.
    //static void ThisWorkerFinishWork();
    //Worker threads barrier:
    //This static method should be called by each
    //worker when finish to process events
    virtual void ThisWorkerEndEventLoop();
    //Worker threads barrier:
    //This method should be called by each
    //worker when worker event loop is terminated.
    typedef std::map<G4int,G4VPhysicalVolume*> masterWorlds_t;
    static G4ScoringManager* GetMasterScoringManager() { return masterScM; }
    static masterWorlds_t& GetMasterWorlds() { return masterWorlds; }
    static void addWorld( G4int counter, G4VPhysicalVolume* w) { masterWorlds.insert( std::make_pair(counter,w) ); }
    const CLHEP::HepRandomEngine* getMasterRandomEngine() const { return masterRNGEngine; }
private:
    //Handling of master thread scoring worlds, access to it is needed by workers
    static G4ScoringManager* masterScM;
    static masterWorlds_t masterWorlds;
    //Singleton implementing master thread behavior
    static G4MTRunManager* fMasterRM;
    G4MTRunManagerKernel* MTkernel;
public: // with description
    static G4MTRunManager* GetMasterRunManager();
    // Returns the singleton instance of the run manager common to all threads implementing 
    // the master behavior
    static G4RunManagerKernel* GetMasterRunManagerKernel();
    static G4MTRunManagerKernel* GetMTMasterRunManagerKernel();
    // Returns the singleton instance of the run manager kernel common to all threads

    virtual void SetUserInitialization(G4VUserPhysicsList* userPL);
    virtual void SetUserInitialization(G4VUserDetectorConstruction* userDC);
    virtual void SetUserInitialization(G4UserWorkerInitialization* userInit);
    virtual void SetUserInitialization(G4UserWorkerThreadInitialization* userInit);
    virtual void SetUserInitialization(G4VUserActionInitialization* userInit);
    virtual void SetUserAction(G4UserRunAction* userAction);
    virtual void SetUserAction(G4VUserPrimaryGeneratorAction* userAction);
    virtual void SetUserAction(G4UserEventAction* userAction);
    virtual void SetUserAction(G4UserStackingAction* userAction);
    virtual void SetUserAction(G4UserTrackingAction* userAction);
    virtual void SetUserAction(G4UserSteppingAction* userAction);

public: 
    // To be invoked solely from G4WorkerRunManager to merge the results
    void MergeScores(const G4ScoringManager* localScoringManager);
    void MergeRun(const G4Run* localRun);
    
public:
    //Handling of more than one run per thread
    enum WorkerActionRequest {
        UNDEFINED ,
        NEXTITERATION ,    // There is another set of UI commands to be executed
        ENDWORKER          // Terminate thread, work finished
    };
        
    virtual WorkerActionRequest ThisWorkerWaitForNextAction();
    //Worker thread barrier
    //This method should be used by workers' run manager to wait,
    //after an event loop for the next action to be performed
    // (for example execute a new run)
    //This returns the action to be performed
protected:
    WorkerActionRequest nextActionRequest;
    virtual void NewActionRequest( WorkerActionRequest newRequest );

protected:
    G4int eventModuloDef;
    G4int eventModulo;
    G4int nSeedsUsed;
    G4int nSeedsFilled;
    G4int nSeedsMax;
    G4int nSeedsPerEvent;
    double* randDbl;

    void RefillSeeds();

public:
    inline void SetEventModulo(G4int i=1) { eventModuloDef = i; }
    inline G4int GetEventModulo() const { return eventModuloDef; }

public:
    virtual void AbortRun(G4bool softAbort=false);
    virtual void AbortEvent();
};

#endif //G4MTRunManager_h