gearbox-devel

[Alexei M. <al...@ca...>]

We are moving towards a proper state machine to describe a subsystem. 
Our subsystems typically have 1-to-1 mapping to threads. A component is 
usually multi-threaded and is made up from several subsystems.

Status of a subsystem is now described in 2 orthogonal dimensions: state 
and health.

alexm


The following is from gbxutilacfr/status.h

// Current state in the subsystem's state machine.
// E.i. what is the subsystem doing?
SubsystemState state;

// Subsystem's health.
// E.i. how is the subsystem doing?
SubsystemHealth health;


//! Possible subsystem status values
enum SubsystemState
{
     //! Subsystem has been created but has not started initialisation 
process.
     SubsystemIdle,
     //! Subsystem is preparing to work, e.g. initialising its 
resources, etc.
     SubsystemInitialising,
     //! Subsystem is fully initialised and is performing its function.
     SubsystemWorking,
     //! Subsystem is preparing to shutdown, e.g. releasing its 
resources, etc.
     SubsystemFinalising,
     //! Subsystem is not longer functioning.
     SubsystemShutdown
};

//! Returns string equivalent of state enumerator.
std::string toString( SubsystemState state );

//! Possible subsystem status values
enum SubsystemHealth
{
     //! Subsystem is OK
     SubsystemOk,
     //! Subsystem has encountered an abnormal but non-fault condition
     SubsystemWarning,
     //! Subsystem has declared a fault
     SubsystemFault,
     //! Subsystem has not been heard from for an abnormally long time
     SubsystemStalled
};