Arranging for periodic actions

Arranging for periodic actions

The Readout software maintains a set of periodic actions that are scheduled when a run is Active. You can add periodic actions of your own to this list. The approximate scheduling resolution of the list is 100ms.

To add a periodic action you must:

• Derive a new class from CTimedEvent. Implement your action in that class's operator() member function.
• Create an instance (object) of that class.
• Register that object with the timer.

The following example, assumes that you have created a Run variable called "temperature" that is intended to hold the temperature of a detector, to be logged during a run. We will assume that:

• getTemperature returns a string version of the temperature.
• m_pTemperature is a pointer to the run variable you want to periodically update.

The example below shows a sample definnitions of the timed event class you might write:

         ...
         class CUpdateTemp : public CTimedEvent
         {
            private:
                CRunVariable* m_pTemp;
            public:
               CUpdateTemp(unsigned int nms, CRunVariable* pTemp) :
                  CTimedEvent(nms),
                  m_pTemp(pTemp) {}
            virtual void operator()();
         };
         ...
         void
         CUpdateTemp::operator()()
         {
            m_pTemp->Set(getTemperature(), TCL_GLOBAL_ONLY);
         }
         ...
      

You can instantiate and register this timer to update e.g. once a second SetupReadout with the code fragment shown below:

         ...
            getClock().EstablishEvent(*(new CTimedEvent(1000, m_pTemperature)));
         ...
      

Arranging for periodic actions