DistrFlags.h

#ifndef LINEARALGEBRA_SRC_MOLPRO_LINALG_ARRAY_UTIL_DISTRFLAGS_H
#define LINEARALGEBRA_SRC_MOLPRO_LINALG_ARRAY_UTIL_DISTRFLAGS_H
#include <memory>
#include <mpi.h>
 
namespace molpro::linalg::array::util {
 
class DistrFlags {
protected:
  class Proxy;
  MPI_Comm m_comm = {};         
  MPI_Win m_win = MPI_WIN_NULL; 
  std::shared_ptr<int> m_counter =
      nullptr; 
public:
  DistrFlags() = default;
  DistrFlags(const DistrFlags &source);
  DistrFlags(DistrFlags &&source) noexcept;
  DistrFlags &operator=(const DistrFlags &source);
  DistrFlags &operator=(DistrFlags &&source) noexcept;
  ~DistrFlags();
 
  DistrFlags(MPI_Comm comm, int value = 0);
 
  friend void swap(DistrFlags &x, DistrFlags &y);
 
  bool empty() const;
 
  Proxy access() const;
  Proxy access(int rank) const;
 
  MPI_Comm communicator() const { return m_comm; }
 
protected:
  class Proxy {
  public:
    Proxy(MPI_Comm comm, MPI_Win win, int rank, std::shared_ptr<int> counter);
    ~Proxy();
    int get() const;
 
    int replace(int val);
 
    int rank() const { return m_rank; }
 
  protected:
    MPI_Comm m_comm = {};           
    MPI_Win m_win = MPI_WIN_NULL;   
    int m_rank;                     
    std::shared_ptr<int> m_counter; 
  };
};
} // namespace molpro::linalg::array::util
 
#endif // LINEARALGEBRA_SRC_MOLPRO_LINALG_ARRAY_UTIL_DISTRFLAGS_H