Utility class to actively monitor the status of a dbus service. More...

#include <ServiceMonitor.h>

Collaboration diagram for ServiceMonitor:

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Public Types
enum class	State { NotRunning , Running , Ready }

Public Member Functions
	ServiceMonitor (const std::shared_ptr< IDobbyIPCUtils > &ipcUtils, const std::shared_ptr< IDobbyUtils > &utils, const IDobbyIPCUtils::BusType &bus, const std::string &serviceName, const AI_IPC::Signal &readySignal, const AI_IPC::Method &queryMethod, const std::function< void(State)> &stateChangeHandler)

State	state () const
	Returns the current state of the service.

void	forceReadyCheck ()
	Sends out an 'is ready' method request to the service.

Private Member Functions
void	onServiceNotification (bool added)
	Callback function called when the daemon service has been added or removed from the bus.

void	onReadyNotification (const AI_IPC::VariantList &args)
	Callback function called when the service daemon has sent a signal saying it's ready to process requests.

bool	onTimer ()
	Timer handler called every second, it sends out a ping request to the daemon if we think it is not alive.

void	sendIsReadyRequest () const
	Sends a method call over dbus asking the service daemon to reply with a ready notification / signal if it is actually there.

Private Attributes
const std::shared_ptr< IDobbyUtils >	mUtilities

const std::shared_ptr< IDobbyIPCUtils >	mIPCUtilities

const IDobbyIPCUtils::BusType	mBusType

const std::string	mServiceName

const AI_IPC::Signal	mReadySignal

const AI_IPC::Method	mQueryMethod

const std::function< void(State)>	mStateChangeHandler

std::mutex	mLock

State	mState

int	mServiceHandlerId

int	mSignalHandlerId

int	mTimerId

Detailed Description

Utility class to actively monitor the status of a dbus service.

Previously this was implemented separately in various plugins, however the process is generic enough that it could be implemented in one object.

The class has the following requirements on the dbus service: a) The dbus service must emit a signal when it is ready b) The dbus service must implement a method to trigger the signal in a) on request.

You can think of a) as a pong message, and b) the ping. The method in b) should not return a value in the method call, instead it should trigger a signal a) if ready.

The class internally implements a timer on a one second period, it will send our feeler requests to see if the service is ready if not already in the ready state.

Member Enumeration Documentation

◆ State

enum class ServiceMonitor::State

strong

Enumerator
NotRunning	dbus service not detected on the bus
Running	dbus service is detected but haven't received the 'ready' signal
Ready	ready signal received

Member Function Documentation

◆ onReadyNotification()

void ServiceMonitor::onReadyNotification ( const AI_IPC::VariantList & args )

private

Callback function called when the service daemon has sent a signal saying it's ready to process requests.

We use this point to adjust the mState state.

Parameters

[in] args Arguments supplied with the signal (ignored).

◆ onServiceNotification()

void ServiceMonitor::onServiceNotification ( bool added )

private

Callback function called when the daemon service has been added or removed from the bus.

We use this point to adjust the mState state.

Parameters

[in] added Will be true if the service arrived on the bus, false if it has left the bus.

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

plugins/Common/include/ServiceMonitor.h
plugins/Common/source/ServiceMonitor.cpp

Public Types

Public Member Functions