Parthenon provides some basic functionality for coordinating various types of calculation in the form of the Driver class and others that derive from it.
Driver is an abstract base class that owns pointers to a ParameterInput object, a Mesh object, and an Outputs object. It has a single pure virtual member function called Execute that must be defined by a derived class and is intended to be called from main(). A simple example of defining an application based on inheriting from this class can be found here.
The EvolutionDriver class derives from Driver, defining the Execute function to carry out the
while (t < tmax) {
// step the solution through time
}loop, including periodic outputs. It has a single pure virtual member function called Step which a derived class must define and which will be called during each pass of the loop above.
The MultiStageDriver derives from the EvolutionDriver, extending it with two new data members. These include a vector of std::string names for the stages of a multi-stage integration scheme and a pointer to an Integrator object which includes members for the number of stages and the stage weights.
The MultiStageBlockTaskDriver derives from the MultiStageDriver, defining the Step function to loop over the stages in a step, constructing and executing task lists per MeshBlock. This class includes a single pure virtual member function called MakeTaskList which must be defined by an application and is responsible for constructing a TaskList for a given MeshBlock and Stage. The driver for the advection example (found here) derives from this class, demonstrating how a simple application based on a multi-stage Runge-Kutta scheme can be built.