GlobalParam.h

#pragma once
 
#include <mutex>
#include <string>
 
#include "Object.h"
 
namespace iguana {

  template <typename T>
  class GlobalParam : public Object
  {
 
    public:

      GlobalParam(T val)
          : Object("IGUANA")
          , m_val(val)
      {}

      GlobalParam<T>& operator=(T const& val)
      {
        std::lock_guard<std::mutex> lock(m_mutex);
        std::call_once(m_once, [&]() { m_val = val; });
        return *this;
      }

      T const operator()()
      {
        std::lock_guard<std::mutex> lock(m_mutex);
        return m_val;
      }
 
    private:
 
      T m_val;
      std::once_flag m_once;
      std::mutex m_mutex;
  };
 
  // ==================================================================================
  // IGUANA GLOBAL PARAMETERS (see source file 'GlobalParam.cc' for their default values)
  // ==================================================================================

  extern GlobalParam<std::string> GlobalConcurrencyModel;

  extern GlobalParam<std::string> GlobalRcdbUrl;
 
}