#include "common/subsys.hpp"

Description

Dependencies and lifecycle of a partially independent Subsystem of the Application.

Using such descriptors, AppState as activated from main() is able to pull up, maintain and shut down the primary parts of the Application.

Note: synchronisation is up to the implementor.

Definition at line 61 of file subsys.hpp.

Public Types
typedef function< void(string *)>	SigTerm

Public Member Functions
Subsys &	depends (Subsys &prereq)
	define a dependency to another Subsys required for running this subsystem

const std::vector< Subsys * >	getPrerequisites ()

bool	isRunning () noexcept

virtual	operator string () const =0
	a human readable name

virtual bool	shouldStart (lumiera::Option &)=0
	query application option state to determine if this subsystem should be activated. More...

virtual bool	start (lumiera::Option &options, SigTerm)=0
	attempt to bring up this subsystem up. More...

virtual void	triggerShutdown () noexcept=0
	initiate termination of this subsystem. More...

Private Member Functions
virtual bool	checkRunningState () noexcept=0
	whether this subsystem is actually operational. More...

Private Member Functions inherited from NonCopyable
	NonCopyable (NonCopyable const &)=delete

NonCopyable &	operator= (NonCopyable const &)=delete

Private Attributes
std::vector< Subsys * >	prereq_

Member Function Documentation

◆ isRunning()

bool isRunning ( )

noexcept

Returns: true if Up

Warning: must not block nor throw.

Definition at line 50 of file subsys.cpp.

References Subsys::checkRunningState().

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◆ shouldStart()

virtual bool shouldStart ( lumiera::Option & )

pure virtual

query application option state to determine if this subsystem should be activated.

Note: even if not started explicitly, it could still be started as prerequisite of another one

Implemented in MockSys, PlayOutSubsysDescriptor, GuiSubsysDescriptor, SessionSubsystem, DummyPlayerSubsysDescriptor, EngineSubsysDescriptor, ScriptRunnerSubsysDescriptor, and NetNodeSubsysDescriptor.

◆ start()

virtual bool start	(	lumiera::Option &	options,
		SigTerm
	)

pure virtual

attempt to bring up this subsystem up.

On return, the subsystem must be operational, according to checkRunningState(). Failure to start up usually terminates the whole application. When this subsystem ceases to work, it must ensure to activate the given callback signal.

Parameters

options	may be influencing the operation mode
SigTerm	to be signalled by the subsystem.

Warning: termination must be signalled reliably.

Returns: true if actually started.

Implemented in MockSys, GuiSubsysDescriptor, PlayOutSubsysDescriptor, SessionSubsystem, DummyPlayerSubsysDescriptor, EngineSubsysDescriptor, ScriptRunnerSubsysDescriptor, and NetNodeSubsysDescriptor.

◆ triggerShutdown()

virtual void triggerShutdown ( )

pure virtualnoexcept

initiate termination of this subsystem.

This trigger may be called repeatedly any time... When the subsystem actually has terminated, the SigTerm passed to start must be invoked.

Note: called within a locked context (barrier)

Warning: must not block nor throw.

Implemented in MockSys, GuiSubsysDescriptor, PlayOutSubsysDescriptor, DummyPlayerSubsysDescriptor, SessionSubsystem, EngineSubsysDescriptor, ScriptRunnerSubsysDescriptor, and NetNodeSubsysDescriptor.

◆ checkRunningState()

virtual bool checkRunningState ( )

privatepure virtualnoexcept

whether this subsystem is actually operational.

When returning false here, the application may terminate at any point without further notice Note further, that a subsystem must not be in running state when signalling termination.

Implemented in MockSys, GuiSubsysDescriptor, PlayOutSubsysDescriptor, DummyPlayerSubsysDescriptor, SessionSubsystem, EngineSubsysDescriptor, ScriptRunnerSubsysDescriptor, and NetNodeSubsysDescriptor.

Referenced by Subsys::isRunning().

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Inheritance diagram for Subsys:

Collaboration diagram for Subsys:

The documentation for this class was generated from the following files:

Description

Public Types

Public Member Functions