epics::pvAccess::Channel Class Reference

The interface through which Operations (get, put, monitor, ...) are initiated. More...

#include <client/pv/pvAccess.h>

Inheritance diagram for epics::pvAccess::Channel:

Collaboration diagram for epics::pvAccess::Channel:

Public Types
enum	ConnectionState { NEVER_CONNECTED, CONNECTED, DISCONNECTED, DESTROYED }
	Channel connection status.
typedef std::tr1::shared_ptr < Channel >	shared_pointer
typedef std::tr1::shared_ptr < const Channel >	const_shared_pointer
typedef std::tr1::weak_ptr < Channel >	weak_pointer
typedef std::tr1::weak_ptr < const Channel >	const_weak_pointer
typedef ChannelRequester	requester_type

Public Member Functions
virtual std::string	getRequesterName ()
	The requester must have a name. More...
virtual void	message (std::string const &message, epics::pvData::MessageType messageType)
virtual std::tr1::shared_ptr < ChannelProvider >	getProvider ()=0
	The ChannelProvider from which this Channel was requested. More...
virtual std::string	getRemoteAddress ()=0
	Returns the channel's remote address, signal name, etc... More...
virtual ConnectionState	getConnectionState ()
	Poll the connection state in more detail.
virtual std::string	getChannelName ()=0
	The name passed to ChannelProvider::createChannel()
virtual std::tr1::shared_ptr < ChannelRequester >	getChannelRequester ()=0
	The ChannelRequester passed to ChannelProvider::createChannel() More...
virtual bool	isConnected ()
	Poll connection state.
virtual void	getField (GetFieldRequester::shared_pointer const &requester, std::string const &subField)
	Initiate a request to retrieve a description of the structure of this Channel. More...
virtual AccessRights	getAccessRights (epics::pvData::PVField::shared_pointer const &pvField)
	Not useful... More...
virtual ChannelProcess::shared_pointer	createChannelProcess (ChannelProcessRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
	Initiate a request for a Process action. More...
virtual ChannelGet::shared_pointer	createChannelGet (ChannelGetRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
	Initiate a request for a Get action. More...
virtual ChannelPut::shared_pointer	createChannelPut (ChannelPutRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
	Initiate a request for a Put action. More...
virtual ChannelPutGet::shared_pointer	createChannelPutGet (ChannelPutGetRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
	Initiate a request for a PutGet action. More...
virtual ChannelRPC::shared_pointer	createChannelRPC (ChannelRPCRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
	Initiate a request for a RPC action. More...
virtual Monitor::shared_pointer	createMonitor (MonitorRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
	Initiate a request for a Monitor action. More...
virtual ChannelArray::shared_pointer	createChannelArray (ChannelArrayRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
	Initiate a request for a Array (get) action. More...
virtual void	printInfo ()
	Prints detailed information about the context to the standard output stream.
virtual void	printInfo (std::ostream &out)
	Prints detailed information about the context to the specified output stream. More...
virtual void	message (std::string const &message, MessageType messageType=errorMessage)
	Push notification.
virtual void	destroy ()
	Destroy this instance.

Static Public Attributes
static size_t	num_instances
static const char *	ConnectionStateNames []

Detailed Description

The interface through which Operations (get, put, monitor, ...) are initiated.

Handle for a Channel returned by ChannelProvider::createChannel()

At any given moment a Channel may be CONNECTED or DISCONNECTED. (NEVER_CONNECTED and DESTORYED are special cases of DISCONNECTED)

A Channel is required to honor calls to Channel::create*() methods while in the disconnected state.

A Channel is required to maintain a strong reference (shared_ptr<>) to the ChannelProvider through which it was created.

Definition at line 886 of file pvAccess.h.

Member Function Documentation

virtual ChannelArray::shared_pointer epics::pvAccess::Channel::createChannelArray ( ChannelArrayRequester::shared_pointer const &  requester, epics::pvData::PVStructure::shared_pointer const &  pvRequest  )

virtual

Initiate a request for a Array (get) action.

ChannelArrayRequester::channelArrayConnect() may be called before createChannelArray() returns, or at some time afterwards.

Failure is indicated by a call to channelArrayConnect with !Error::isOk()

Precondition

The Channel need not be CONNECTED

Postcondition

The returned ChannelArray will hold a strong reference to the provided MonitorRequester.

Returned shared_ptr<ChannelArray> will have unique()==true.

Returns

A non-NULL ChannelArray unless channelArrayConnect() called with an Error

Create a ChannelArray.

Parameters

channelArrayRequester	The ChannelArrayRequester
pvRequest	Additional options (e.g. triggering).

Returns

ChannelArray instance.

Note

The default implementation yields a not implemented error

virtual ChannelGet::shared_pointer epics::pvAccess::Channel::createChannelGet ( ChannelGetRequester::shared_pointer const &  requester, epics::pvData::PVStructure::shared_pointer const &  pvRequest  )

virtual

Initiate a request for a Get action.

ChannelGetRequester::channelGetConnect() may be called before createChannelGet() returns, or at some time afterwards.

Failure is indicated by a call to channelProcessConnect with !Error::isOk()

Precondition

The Channel need not be CONNECTED

Postcondition

The returned ChannelGet will hold a strong reference to the provided ChannelGetRequester.

Returned shared_ptr<ChannelGet> will have unique()==true.

Returns

A non-NULL ChannelGet unless channelGetConnect() called with an Error

Note

The default implementation proxies to createChannelPut()

virtual ChannelProcess::shared_pointer epics::pvAccess::Channel::createChannelProcess ( ChannelProcessRequester::shared_pointer const &  requester, epics::pvData::PVStructure::shared_pointer const &  pvRequest  )

virtual

Initiate a request for a Process action.

ChannelProcessRequester::channelProcessConnect() may be called before createChannelProcess() returns, or at some time afterwards.

Failure is indicated by a call to channelProcessConnect with !Error::isOk()

Precondition

The Channel need not be CONNECTED

Postcondition

The returned ChannelProcess will hold a strong reference to the provided ChannelProcessRequester.

Returned shared_ptr<ChannelProcess> will have unique()==true.

Returns

A non-NULL ChannelProcess unless channelProcessConnect() called with an Error

Note

The default implementation proxies using createChannelPut() and ChannelPut::put() with no data (empty bit set)

virtual ChannelPut::shared_pointer epics::pvAccess::Channel::createChannelPut ( ChannelPutRequester::shared_pointer const &  requester, epics::pvData::PVStructure::shared_pointer const &  pvRequest  )

virtual

Initiate a request for a Put action.

ChannelPutRequester::channelPutConnect() may be called before createChannelPut() returns, or at some time afterwards.

Failure is indicated by a call to channelProcessConnect with !Error::isOk()

Precondition

The Channel need not be CONNECTED

Postcondition

The returned ChannelPut will hold a strong reference to the provided ChannelPutRequester.

Returned shared_ptr<ChannelPut> will have unique()==true.

Returns

A non-NULL ChannelPut unless channelPutConnect() called with an Error

Note

The default implementation yields a not implemented error

virtual ChannelPutGet::shared_pointer epics::pvAccess::Channel::createChannelPutGet ( ChannelPutGetRequester::shared_pointer const &  requester, epics::pvData::PVStructure::shared_pointer const &  pvRequest  )

virtual

Initiate a request for a PutGet action.

ChannelPutGetRequester::channelPutGetConnect() may be called before createChannelPutGet() returns, or at some time afterwards.

Failure is indicated by a call to channelProcessConnect with !Error::isOk()

Precondition

The Channel need not be CONNECTED

Postcondition

The returned ChannelPutGet will hold a strong reference to the provided ChannelPutGetRequester.

Returned shared_ptr<ChannelPutGet> will have unique()==true.

Returns

A non-NULL ChannelPutGet unless channelPutGetConnect() called with an Error

Note

The default implementation yields a not implemented error

virtual ChannelRPC::shared_pointer epics::pvAccess::Channel::createChannelRPC ( ChannelRPCRequester::shared_pointer const &  requester, epics::pvData::PVStructure::shared_pointer const &  pvRequest  )

virtual

Initiate a request for a RPC action.

ChannelRPCRequester::channelRPCConnect() may be called before createChannelRPC() returns, or at some time afterwards.

Failure is indicated by a call to channelProcessConnect with !Error::isOk()

Precondition

The Channel need not be CONNECTED

Postcondition

The returned ChannelRPC will hold a strong reference to the provided ChannelRPCRequester.

Returned shared_ptr<ChannelRPC> will have unique()==true.

Returns

A non-NULL ChannelRPC unless channelRPCConnect() called with an Error

Note

The default implementation yields a not implemented error

virtual Monitor::shared_pointer epics::pvAccess::Channel::createMonitor ( MonitorRequester::shared_pointer const &  requester, epics::pvData::PVStructure::shared_pointer const &  pvRequest  )

virtual

Initiate a request for a Monitor action.

MonitorRequester::channelMonitorConnect() may be called before createMonitor() returns, or at some time afterwards.

Failure is indicated by a call to monitorConnect with !Error::isOk()

Precondition

The Channel need not be CONNECTED

Postcondition

The returned Monitor will hold a strong reference to the provided MonitorRequester.

Returned shared_ptr<Monitor> will have unique()==true.

Returns

A non-NULL Monitor unless monitorConnect() called with an Error

Note

The default implementation yields a not implemented error

virtual AccessRights epics::pvAccess::Channel::getAccessRights ( epics::pvData::PVField::shared_pointer const &  pvField )

virtual

Not useful...

Parameters

pvField

The field for which access rights is desired.

Returns

The access rights.

virtual std::tr1::shared_ptr<ChannelRequester> epics::pvAccess::Channel::getChannelRequester ( )

pure virtual

The ChannelRequester passed to ChannelProvider::createChannel()

Exceptions

std::tr1::bad_weak_ptr

virtual void epics::pvAccess::Channel::getField ( GetFieldRequester::shared_pointer const &  requester, std::string const &  subField  )

virtual

Initiate a request to retrieve a description of the structure of this Channel.

While the type described by calls to getField() should match what is provided for all operations except RPC.

GetFieldRequester::getDone() will be called before getField() returns, or at some time afterwards.

Parameters

Requester	The Requester.
subField	Empty string, or the field name of a sub-structure.

virtual std::tr1::shared_ptr<ChannelProvider> epics::pvAccess::Channel::getProvider ( )

pure virtual

The ChannelProvider from which this Channel was requested.

May never be NULL.

virtual std::string epics::pvAccess::Channel::getRemoteAddress ( )

pure virtual

Returns the channel's remote address, signal name, etc...

For example:

• client side channel would return server's address, e.g. "/192.168.1.101:5064"
• server side channel would return underlying bus address, e.g. "#C0 S1".

The value returned here will changed depending on the connection status. A disconnected channel should return an empty() string.

virtual std::string epics::pvAccess::Channel::getRequesterName ( )

virtual

The requester must have a name.

Returns

The requester's name.

Implements epics::pvAccess::Requester.

virtual void epics::pvAccess::Channel::printInfo ( std::ostream &  out )

inlinevirtual

Prints detailed information about the context to the specified output stream.

Parameters

out	the output stream.

Definition at line 1132 of file pvAccess.h.

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

• client/pv/pvAccess.h