pvas::SharedPV Class Reference

A Shared State Process Variable (PV) More...

#include <server/pva/sharedstate.h>

Inheritance diagram for pvas::SharedPV:

Collaboration diagram for pvas::SharedPV:

Classes
struct	Handler
	Callbacks associated with a SharedPV. More...

Public Types
typedef std::tr1::shared_ptr < SharedPV >	shared_pointer
typedef std::tr1::shared_ptr < const SharedPV >	const_shared_pointer
typedef std::tr1::weak_ptr < SharedPV >	weak_pointer
typedef std::tr1::weak_ptr < const SharedPV >	const_weak_pointer

Public Member Functions
void	setHandler (const std::tr1::shared_ptr< Handler > &handler)
	Replace Handler given with ctor.
Handler::shared_pointer	getHandler () const
bool	isOpen () const
	test open-ness. cf. open() and close()
void	open (const epics::pvData::PVStructure &value)
	Shorthand for. More...
void	open (const epics::pvData::PVStructure &value, const epics::pvData::BitSet &valid)
	Begin allowing clients to connect. More...
void	open (const epics::pvData::StructureConstPtr &type)
	Shorthand for. More...
void	close (bool destroy=false)
	Force any clients to disconnect, and prevent re-connection. More...
std::tr1::shared_ptr < epics::pvData::PVStructure >	build ()
	Create a new container which may be used to prepare to call post(). More...
void	post (const epics::pvData::PVStructure &value, const epics::pvData::BitSet &changed)
	Update the cached PVStructure in this SharedPV. More...
void	fetch (epics::pvData::PVStructure &value, epics::pvData::BitSet &valid)
	Update arguments with current value, which is the initial value from open() with accumulated post() calls.
virtual std::tr1::shared_ptr < epics::pvAccess::Channel >	connect (const std::tr1::shared_ptr< epics::pvAccess::ChannelProvider > &provider, const std::string &channelName, const std::tr1::shared_ptr< epics::pvAccess::ChannelRequester > &requester)
	may call Handler::onFirstConnect() More...
virtual void	disconnect (bool destroy, const epics::pvAccess::ChannelProvider *provider)
	Disconnect all Channels created through the given ChannelProvider. More...
void	setDebug (int lvl)
int	isDebug () const

Static Public Member Functions
static shared_pointer	build (const std::tr1::shared_ptr< Handler > &handler, Config *conf=0)
	Allocate a new PV in the closed state. More...
static shared_pointer	buildReadOnly (Config *conf=0)
	A SharedPV which fails all Put and RPC operations. In closed state.
static shared_pointer	buildMailbox (Config *conf=0)
	A SharedPV which accepts all Put operations, and fails all RPC operations. In closed state.

Friends
struct	detail::SharedChannel
struct	detail::SharedMonitorFIFO
struct	detail::SharedPut
struct	detail::SharedRPC
void	epics::pvAccess::providerRegInit (void *)

Detailed Description

A Shared State Process Variable (PV)

"Shared" in the sense that all clients/subscribers interact with the same PVStructure (excluding the RPC operation).

Warning

For the purposes of locking, this class is an Operation. eg. no locks may be held when calling post(), open(), close(), or connect(). provider_roles_requester_locking

This class contains a cached PVStructure, which is updated by post(), also a list of subscribing clients and in-progress network Operations.

On construction a SharedPV is in a "disconnected" state. It has no associated PVStructure (or Structure). No type. A type is associated via the open() method. After it has been open()'d. Calls to post() may be made. Calling close() will close all currently opened client channels.

Client channels, and operations on them, may be initiated at any time (via connect()). However, operations other than RPC will not proceed until open() is called.

Note

A SharedPV does not have a name. Name(s) are associated with a SharedPV By a Provider (StaticProvider, DynamicProvider, or any epics::pvAccess::ChannelProvider). These channel names may be seen via connect()

See Also

Server API shared_ptr Ownership

Definition at line 76 of file sharedstate.h.

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

• server/pva/sharedstate.h