Class IAlgorithm

Class Documentation

class mimir::IAlgorithm

Algorithm interface class.

A mimir::StateMachine holds an instance of a class that is inherited from IAlgorithm. The interface functions are the only directly exposed interactions with the algorithm. These functions drives the state machine under normal circumstances by post appropriate events to the state machine. Each function, except name(), is an asynchronous call using the std::future mechanism. The std::atomic<bool> parameter is an external boolean whether the algorithm should cancel its workload.

Public Functions

inline virtual ~IAlgorithm()

Destructor.

virtual void solve(const std::atomic<bool> &cancel_token) = 0

Function to run the actual algorithm. Called at the entry of mimir::Evaluating.

Solves the algorithm problem. If the solution time is perceived as long, intermittent checks for cancel_token should be performed to provide graceful cancellation of the workload.

  • If solving fails, post an mimir::EvError event.

  • When evaluation is successful, post mimir::EvReady.

  • If cancel_token is true, post mimir::EvInterrupt.

Parameters

cancel_token – [in] atomic boolean whether an external cancel has been issued.

virtual void initialize(const std::atomic<bool> &cancel_token) = 0

Function called when entering the mimir::Initializing state of the mimir::StateMachine.

Prepares the algorithm, e.g. by retrieving input data like initial conditions from DDS.

  • If cancel_token is true, the function shall post a mimir::EvInterrupt event. The boolean should be checked regularly.

  • If initialization fails, post an mimir::EvError event.

  • If initialization is done, post mimir::EvReady.

Parameters

cancel_token – [in] atomic boolean whether an external cancel has been issued.

virtual void timer(const std::atomic<bool> &cancel_token) = 0

Timer function that posts mimir::EvTimeout when the time duration is spent.

This function is called when entering mimir::Waiting of mimir::StateMachine. How the timer is implemented is up to the implementor. Possible patterns can be regular intervals, state/logic-dependent durations. A common use case is that the timer waits the remainder of a fixed interval, for which solve() has spent the initial part.

The function shall contain the sleep logic, using e.g. std::this_thread::sleep_for(), and post appropriate events:

  • If cancel_token is true, the function shall post a mimir::EvInterrupt event. The boolean should be checked regularly.

  • If the algorithm-specified time duration has passed, post a mimir::EvTimeout.

Parameters

cancel_token – [in] atomic boolean whether an external cancel has been issued.

virtual const char *name() = 0

Name identifier string for the implemented algorithm.