Sample Mechanism base, has a ProcessVariable and filters its values. More...

#include <SampleMechanism.h>

Inheritance diagram for SampleMechanism:

Public Member Functions
	SampleMechanism (const EngineConfig &config, ProcessVariableContext &ctx, const char name, double period, ProcessVariableListener disable_filt_listener)
	Construct mechanism for given period. More...

virtual unsigned long	write (Guard &guard, Index &index)=0
	Write current buffer to index. More...

virtual std::string	getInfo (Guard &guard)

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

virtual void	stop (Guard &guard)
	Stop sampling. More...

virtual void	addToFUX (Guard &guard, FUX::Element *doc)
	Append this sample mechanism to a FUX document. More...

virtual void	pvConnected (ProcessVariable &pv, const epicsTime &when)=0
	ProcessVariableStateListener. More...

void	pvDisconnected (ProcessVariable &pv, const epicsTime &when)
	ProcessVariableStateListener. More...

virtual void	pvValue (ProcessVariable &pv, const RawValue::Data *data)=0
	ProcessVariableValueListener. More...

virtual OrderedMutex &	getMutex ()

virtual const std::string &	getName () const
	Gets the ProcessVariable name. More...

bool	isRunning (Guard &guard)

ProcessVariable::State	getPVState ()

void	disable (const epicsTime &when)
	Temporarily disable sampling. More...

void	enable (const epicsTime &when)
	Re-enable sampling. More...

void	addStateListener (ProcessVariableStateListener *listener)
	Add a listener to the underlying PV. More...

void	removeStateListener (ProcessVariableStateListener *listener)
	Remove a listener from the underlying PV. More...

void	addValueListener (ProcessVariableValueListener *listener)
	Add a listener to the underlying PV. More...

void	removeValueListener (ProcessVariableValueListener *listener)
	Remove a listener from the underlying PV. More...

Public Member Functions inherited from ProcessVariableStateListener
virtual	~ProcessVariableStateListener ()
	Constructor.

Detailed Description

Sample Mechanism base, has a ProcessVariable and filters its values.

This base class for all sample mechanisms maintains the ProcessVariable start/stop, and also has a DisableFilter.

Data from the PV goes to the DisableFilter, via which the enable/disable is implemented. Derived sample mechanisms will probably add more filters, until finally invoking the ProcessVariableListener interface of the base SampleMechanism.

The ProcessVariableListener implementation in the base SampleMechanism logs "Disconnected" on pvDisconnected(), and otherwise adds every pvValue to the CircularBuffer.

Uses 'virtual Named' so we can implement other 'Named' interfaces in derived SampleMechanisms and still only get one 'Named' base.

Constructor & Destructor Documentation

SampleMechanism::SampleMechanism	(	const EngineConfig &	config,
		ProcessVariableContext &	ctx,
		const char *	name,
		double	period,
		ProcessVariableListener *	disable_filt_listener
	)

Construct mechanism for given period.

Parameters

config	The global configuration.
ctx	The ProcessVariableContext to use for the pv.
name	The pv name to connect to.
period	The sample period. Use differs with derived class.
disable_filt_listener	The next listener after the DisableFilter.

The disable_filt_listener would typically be another ProcessVariableFilter, linking to yet another one, and the final filter then sends PV events to the SampleMechanism. The derived SampleMechanisms provide those intermediate PV filters and point the last one to the basic SampleMechanism, so the derived mechanisms don't need a PV listener in the constructor.

Member Function Documentation

void SampleMechanism::addStateListener ( ProcessVariableStateListener * listener )

inline

Add a listener to the underlying PV.

virtual void SampleMechanism::addToFUX	(	Guard &	guard,
		FUX::Element *	doc
	)

virtual

Append this sample mechanism to a FUX document.

Reimplemented in SampleMechanismMonitoredGetEA3, SampleMechanismGetEA3, and SampleMechanismMonitoredEA3.

void SampleMechanism::addValueListener ( ProcessVariableValueListener * listener )

inline

Add a listener to the underlying PV.

void SampleMechanism::disable ( const epicsTime & when )

Temporarily disable sampling.

See Also: enable()

void SampleMechanism::enable ( const epicsTime & when )

Re-enable sampling.

See Also: disable()

virtual std::string SampleMechanism::getInfo ( Guard & guard )

virtual

Returns: Returns a description of mechanism and current state.

Reimplemented in SampleMechanismMonitoredGetEA3, SampleMechanismGetEA3, and SampleMechanismMonitoredEA3.

virtual OrderedMutex& SampleMechanism::getMutex ( )

virtual

Returns: Returns the mutex for the SampleMechanism.

See Also: Guardable

Implements Guardable.

virtual const std::string& SampleMechanism::getName ( ) const

virtual

Gets the ProcessVariable name.

See Also: NamedAbstractBase

Implements Named.

ProcessVariable::State SampleMechanism::getPVState ( )

Returns: Returns the state of the ProcessVariable.

bool SampleMechanism::isRunning ( Guard & guard )

Returns: Returns true if start has been invoked until stop().

virtual void SampleMechanism::pvConnected	(	ProcessVariable &	pv,
		const epicsTime &	when
	)

pure virtual

ProcessVariableStateListener.

Base implementation allocates circular buffer

Implements ProcessVariableStateListener.

Implemented in SampleMechanismMonitoredGetEA3, SampleMechanismMonitoredEA3, and SampleMechanismEA3.

void SampleMechanism::pvDisconnected	(	ProcessVariable &	pv,
		const epicsTime &	when
	)

virtual

ProcessVariableStateListener.

Base implementation adds a "DISCONNECTED" marker.

Implements ProcessVariableStateListener.

virtual void SampleMechanism::pvValue	(	ProcessVariable &	pv,
		const RawValue::Data *	data
	)

pure virtual

ProcessVariableValueListener.

Base implementation adds data to buffer. In addition, the initial value after a new connection is also logged with the host time stamp. For PVs that never change, this helps because the original time stamp might be before the last 'disconnect', so this gives us an idea of when the PV connected.

Implements ProcessVariableValueListener.

Implemented in SampleMechanismEA3.

void SampleMechanism::removeStateListener ( ProcessVariableStateListener * listener )

inline

Remove a listener from the underlying PV.

void SampleMechanism::removeValueListener ( ProcessVariableValueListener * listener )

inline

Remove a listener from the underlying PV.

virtual void SampleMechanism::start ( Guard & guard )

virtual

Start the sample mechanism.

Base implementation starts the PV.