// This may look like C code, but it is really -*- C++ -*-
// UPS - LAL (Orsay) / IN2P3/CNRS  -  IRFU/SPP (Saclay) / CEA
#ifndef PARLEX_SEEN
#define PARLEX_SEEN

// Classes pour execution de taches paralleles en utilisant les threads
//    R. Ansari       UPS+LAL IN2P3/CNRS  2005

#include "zthread.h"
#include <vector>

namespace SOPHYA {
using namespace std; 

//--------------------------------------------------------------------
//  Interface pour les objets ayant une fonction (Execute()) pouvant 
//  s'executer en parallele
//--------------------------------------------------------------------
/*!
  \class ParallelTaskInterface
  \ingroup SysTools
  \brief Interface definition for parallel task object. 

  The pure virtual method execute() should be redefined by the classes
  inheriting from ParallelTaskInterface
*/  
class ParallelTaskInterface {
public:
  explicit       ParallelTaskInterface()  { }
  virtual        ~ParallelTaskInterface() { }
  /*! This method should perform the actual computation. The parameter tid 
    is used by the ParallelExecutor class to identify the thread calling the method
  */
  virtual int    execute(int tid) = 0; 
};

//---- Implementation de ParallelTaskInterface pour l'execution des fonctions 
typedef int (* ParalExFunction) (int);
//----
class ParallelTaskFunction {
public:
  explicit       ParallelTaskFunction(ParalExFunction f);
  virtual int    execute(int tid);
 
  ParalExFunction parfunc_;
};

//--------------------------------------------------------------------
//  Classe de thread permettant l'execution controle de la methode 
//   ParallelTaskInterface::Execute() 
//--------------------------------------------------------------------
class ParalExThread : public ZThread {
public:
  explicit       ParalExThread(ParallelTaskInterface& ptask, int tid);
  virtual void   run();

  // demarre l'execution (start() doit etre appele avant)  
  //! 
  int    go();
  // Attend la fin  de l'execution 
  int    waitEndOfExecution();
  // Termine (arrete) l'execution du thread . si fgwait==true, attend l'arret effectif du tread.
  void   terminate(bool fgwait=true);
  // demarre l'execution et attend sa fin
  //! Launches the execution of ptask_.execute() and waits for its ending.
  inline int execute() 
  { 
    int rc=go();
    if(rc!=0) return rc;
    return waitEndOfExecution();
  }
  //! Return the the execution phase, 0: waiting, 1:go called, 2: executing, 3: execution finished 
  inline int getExecutionState() { return state_; }
  //! Return true if an exception has been catched when ptask_.execute() called, and correspond message
  inline bool IfException(string& msg)
     {  msg=msg_exc_;  return fgexcept_; }

  //! Return reference to the parallel task object  
  inline ParallelTaskInterface& getParallelTask() { return ptask_; }
  //! Set (changes) the parallel task object. 
  int setParallelTask(ParallelTaskInterface& ptask);
  //! Return the rank or thread-id in a parallel execution context
  inline int Rank() { return tid_; }

protected: 
  ParallelTaskInterface& ptask_;
  int tid_;
  ZMutex mtx_;
  int state_;     //  running state  
// 0:idle, 1: go, 2: executing, 3: executionfinished , 6:terminatethread, 7:threadfinished 
  bool fgexcept_;  // true -> exception lors de l'execution de ptask_.execute() 
  string msg_exc_;  // message d'exception le cas echeant 
};

//--------------------------------------------------------------------
//  Classe permettant l'execution simultanee de plusieurs fonctions 
//   ParallelTaskInterface::Execute() 
//--------------------------------------------------------------------
class ParallelExecutor {
public:
  explicit      ParallelExecutor(ParallelTaskInterface& ptask, size_t nthr); 
  explicit      ParallelExecutor(vector< ParallelTaskInterface * > vptask); 
  virtual       ~ParallelExecutor();

  //! Set (changes) the parallel task objects (same object for all threads)
  void SetParallelTask( ParallelTaskInterface& ptask );
  //! Set (changes) the parallel task objects 
  void SetParallelTask( vector< ParallelTaskInterface * > vptask);

  //! Starts all the parallel threads 
  virtual void  start();
  // Appel a l'execution parallele
  virtual int   execute();
  //! Return the number of parallel threads 
  inline  size_t  nThreads()  { return vpext_.size(); }
  //! Return RC for the ParalleTask.execute() of thread i 
  inline  int     getRC(size_t i) { return vrc_[i]; }
  //! Return the execption condition for the ParalleTask.execute() of thread i 
  inline  bool    IfException(size_t i, string& msg)  { return vpext_[i]->IfException(msg); }

protected:
  vector<ParalExThread *> vpext_; 
  vector<int> vrc_;
  bool fgstarted_;   // true -> les threads tournent (thr[i].start() appeles)
  bool fgrunning_;   // true -> en cours d'execution 
};

} // namespace SOPHYA

#endif