One process variable. More...

#include <ProcessVariable.h>

Inheritance diagram for ProcessVariable:

Public Types
enum	State { INIT, DISCONNECTED, GETTING_INFO, CONNECTED }
	Possible states of a ProcessVariable. More...

Public Member Functions
	ProcessVariable (ProcessVariableContext &ctx, const char *name)
	Create a ProcessVariable with given name. More...

virtual	~ProcessVariable ()
	Destructor. More...

OrderedMutex &	getMutex ()

State	getState (Guard &guard) const

bool	isConnected (Guard &guard) const

const char *	getStateStr (Guard &guard) const

const char *	getCAStateStr (Guard &guard) const

DbrType	getDbrType (Guard &guard) const
	Get the DBR_TIME_... More...

DbrCount	getDbrCount (Guard &guard) const
	Get the array size of this PV. More...

const CtrlInfo &	getCtrlInfo (Guard &guard) const

void	addStateListener (ProcessVariableStateListener *listener)
	Add a ProcessVariableStateListener. More...

void	removeStateListener (ProcessVariableStateListener *listener)
	Remove a ProcessVariableStateListener. More...

void	addValueListener (ProcessVariableValueListener *listener)
	Add a ProcessVariableValueListener. More...

void	removeValueListener (ProcessVariableValueListener *listener)
	Remove a ProcessVariableValueListener. More...

void	addListener (ProcessVariableListener *listener)
	Add a ProcessVariableListener. More...

void	removeListener (ProcessVariableListener *listener)
	Remove a ProcessVariableListener. More...

void	start (Guard &guard)
	Start the connection mechanism. More...

bool	isRunning (Guard &guard)

void	getValue (Guard &guard)
	Perform a single 'get'. More...

void	subscribe (Guard &guard)
	Subscribe for value updates. More...

bool	isSubscribed (Guard &guard) const

void	unsubscribe (Guard &guard)
	Unsubscribe, no more updates. More...

void	stop (Guard &guard)
	Disconnect. More...

Public Member Functions inherited from NamedBase
	NamedBase (const char *name)
	Create a Named thing with given name. More...

const stdString &	getName () const

Detailed Description

One process variable.

Handles the connect/disconnect, also requests the full information (DBR_CTRL_...) and from then on get/monitor will only get the DBR_TIME_...

Locking: The ProcessVariable and the ProcessVariableContext call into the ChannelAccess client library. The CA client library also invokes callbacks in the ProcessVariable. To avoid deadlocks between ProcessVariable and CA semaphores, the ProcessVariable unlocks itself before calling any CA library. This means, however, that one should not otherwise modify the ProcessVariable while it is dealing with the CA client library. To help enforce this, the add/removeListener calls are only allowed while the ProcessVariable is not running.

Member Enumeration Documentation

enum ProcessVariable::State

Possible states of a ProcessVariable.

Enumerator
INIT	Not initialized.
DISCONNECTED	Not connected, but trying to connect.
GETTING_INFO	Received CA connection callback, getting control info.
CONNECTED	Fully connected.

Constructor & Destructor Documentation

ProcessVariable::ProcessVariable	(	ProcessVariableContext &	ctx,
		const char *	name
	)

Create a ProcessVariable with given name.

virtual ProcessVariable::~ProcessVariable ( )

virtual

Destructor.

Member Function Documentation

void ProcessVariable::addListener ( ProcessVariableListener * listener )

inline

Add a ProcessVariableListener.

void ProcessVariable::addStateListener ( ProcessVariableStateListener * listener )

inline

Add a ProcessVariableStateListener.

void ProcessVariable::addValueListener ( ProcessVariableValueListener * listener )

inline

Add a ProcessVariableValueListener.

const char* ProcessVariable::getCAStateStr ( Guard & guard ) const

Returns: Returns the ChannelAccess state.

const CtrlInfo & ProcessVariable::getCtrlInfo ( Guard & guard ) const

inline

Returns: Returns the control information.

DbrCount ProcessVariable::getDbrCount ( Guard & guard ) const

inline

Get the array size of this PV.

Only valid when getState() was CONNECTED

DbrType ProcessVariable::getDbrType ( Guard & guard ) const

inline

Get the DBR_TIME_...

type of this PV.

Only valid when getState() was CONNECTED

OrderedMutex& ProcessVariable::getMutex ( )

virtual

See Also: Guardable

Implements Guardable.

State ProcessVariable::getState ( Guard & guard ) const

Returns: Returns the current state.

const char* ProcessVariable::getStateStr ( Guard & guard ) const

Returns: Returns the current state.

void ProcessVariable::getValue ( Guard & guard )

Perform a single 'get'.

Value gets delivered to listeners.

bool ProcessVariable::isConnected ( Guard & guard ) const

inline

Returns: Returns true if the current state is CONNECTED.

bool ProcessVariable::isRunning ( Guard & guard )

Returns: Returns true if start() has been called but not stop().

See Also: start()

bool ProcessVariable::isSubscribed ( Guard & guard ) const

inline

Returns: Returns 'true' if we are subscribed.

void ProcessVariable::removeListener ( ProcessVariableListener * listener )

inline

Remove a ProcessVariableListener.

void ProcessVariable::removeStateListener ( ProcessVariableStateListener * listener )

inline

Remove a ProcessVariableStateListener.

void ProcessVariable::removeValueListener ( ProcessVariableValueListener * listener )

inline

Remove a ProcessVariableValueListener.

void ProcessVariable::start ( Guard & guard )

Start the connection mechanism.

See Also: stop(); isRunning()

void ProcessVariable::stop ( Guard & guard )

Disconnect.

See Also: start()

void ProcessVariable::subscribe ( Guard & guard )

Subscribe for value updates.

Values get delivered to listeners.

void ProcessVariable::unsubscribe ( Guard & guard )

Unsubscribe, no more updates.

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

/home/malitsky/projects/epics-archiver/sourceforge/trunk/ea4-cpp/include/common/engine/ProcessVariable.h

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation