epics::pvAccess::Channel Class Reference

#include "pvAccess.h"

Inheritance diagram for epics::pvAccess::Channel:

Collaboration diagram for epics::pvAccess::Channel:

Public Types
enum	ConnectionState { NEVER_CONNECTED, CONNECTED, DISCONNECTED, DESTROYED }
typedef ChannelRequester	requester_type

Public Member Functions
	POINTER_DEFINITIONS (Channel)
	Channel ()
virtual	~Channel ()
virtual std::string	getRequesterName ()
virtual void	message (std::string const &message, epics::pvData::MessageType messageType)
virtual std::tr1::shared_ptr< ChannelProvider >	getProvider ()=0
virtual std::string	getRemoteAddress ()=0
virtual ConnectionState	getConnectionState ()
virtual std::string	getChannelName ()=0
virtual std::tr1::shared_ptr< ChannelRequester >	getChannelRequester ()=0
virtual bool	isConnected ()
virtual void	getField (GetFieldRequester::shared_pointer const &requester, std::string const &subField)
virtual AccessRights	getAccessRights (epics::pvData::PVField::shared_pointer const &pvField)
virtual ChannelProcess::shared_pointer	createChannelProcess (ChannelProcessRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
virtual ChannelGet::shared_pointer	createChannelGet (ChannelGetRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
virtual ChannelPut::shared_pointer	createChannelPut (ChannelPutRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
virtual ChannelPutGet::shared_pointer	createChannelPutGet (ChannelPutGetRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
virtual ChannelRPC::shared_pointer	createChannelRPC (ChannelRPCRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
virtual Monitor::shared_pointer	createMonitor (MonitorRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
virtual ChannelArray::shared_pointer	createChannelArray (ChannelArrayRequester::shared_pointer const &requester, epics::pvData::PVStructure::shared_pointer const &pvRequest)
virtual void	printInfo ()
virtual void	printInfo (std::ostream &out)
Public Member Functions inherited from epics::pvAccess::Requester
	POINTER_DEFINITIONS (Requester)
virtual	~Requester ()
virtual void	message (std::string const &message, MessageType messageType=errorMessage)
Public Member Functions inherited from epics::pvAccess::Destroyable
	POINTER_DEFINITIONS (Destroyable)
virtual void	destroy ()=0

Static Public Attributes
static size_t	num_instances
static const char *	ConnectionStateNames [] = { "NEVER_CONNECTED", "CONNECTED", "DISCONNECTED", "DESTROYED" }

Additional Inherited Members
Protected Member Functions inherited from epics::pvAccess::Destroyable
virtual	~Destroyable ()

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 Typedef Documentation

typedef ChannelRequester epics::pvAccess::Channel::requester_type

Definition at line 893 of file pvAccess.h.

Member Enumeration Documentation

enum epics::pvAccess::Channel::ConnectionState

Channel connection status.

Enumerator
NEVER_CONNECTED
CONNECTED
DISCONNECTED
DESTROYED

Definition at line 906 of file pvAccess.h.

                         {
        NEVER_CONNECTED, CONNECTED, DISCONNECTED, DESTROYED
    };

Constructor & Destructor Documentation

epics::pvAccess::Channel::Channel

(

)

Definition at line 26 of file pvAccess.cpp.

{REFTRACE_INCREMENT(num_instances);}

epics::pvAccess::Channel::~Channel ( )

virtual

Definition at line 27 of file pvAccess.cpp.

{REFTRACE_DECREMENT(num_instances);}

Member Function Documentation

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

Definition at line 365 of file pvAccess.cpp.

{
    ChannelArray::shared_pointer ret;
    requester->channelArrayConnect(pvd::Status(pvd::Status::STATUSTYPE_FATAL, "Not Implemented"),
                                   ret, pvd::Array::const_shared_pointer());
    return ret;
}

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()

Definition at line 308 of file pvAccess.cpp.

{
    std::tr1::shared_ptr<Get2PutProxy> ret(new Get2PutProxy);
    ret->op_request.reset(new Get2PutProxy::Req(requester, ret));

    ChannelPut::shared_pointer op(createChannelPut(ret->op_request, pvRequest));
    if(!op) {
        ret.reset();
    } else {
        epicsGuard<epicsMutex> G(ret->op_request->mutex);
        ret->op = op;
    }

    return ret;
}

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)

Definition at line 167 of file pvAccess.cpp.

{
    pvd::PVStructure::shared_pointer pvRequest(pvRequestx);
    std::tr1::shared_ptr<Process2PutProxy> ret(new Process2PutProxy);
    ret->op_request.reset(new Process2PutProxy::Req(requester, ret));

    // inject record._options.process=true if client hasn't provided
    if(!pvRequest->getSubField("record._options.process"))
    {
        pvRequest = pvd::ValueBuilder(*pvRequest)
                     .addNested("record")
                         .addNested("_options")
                            .add<pvd::pvString>("process", "true")
                         .endNested()
                     .endNested()
                     .buildPVStructure();
    }

    ChannelPut::shared_pointer op(createChannelPut(ret->op_request, pvRequest));
    if(!op) {
        ret.reset();
    } else {
        epicsGuard<epicsMutex> G(ret->op_request->mutex);
        ret->op = op;
    }

    return ret;
}

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

Definition at line 326 of file pvAccess.cpp.

{
    ChannelPut::shared_pointer ret;
    requester->channelPutConnect(pvd::Status(pvd::Status::STATUSTYPE_FATAL, "Not Implemented"),
                                 ret, pvd::StructureConstPtr());
    return ret;
}

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

Definition at line 336 of file pvAccess.cpp.

{
    ChannelPutGet::shared_pointer ret;
    requester->channelPutGetConnect(pvd::Status(pvd::Status::STATUSTYPE_FATAL, "Not Implemented"),
                                    ret, pvd::StructureConstPtr(), pvd::StructureConstPtr());
    return ret;
}

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

Reimplemented in epics::pvAccess::RPCChannel.

Definition at line 346 of file pvAccess.cpp.

{
    ChannelRPC::shared_pointer ret;
    requester->channelRPCConnect(pvd::Status(pvd::Status::STATUSTYPE_FATAL, "Not Implemented"), ret);
    return ret;
}

pvd::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

Definition at line 355 of file pvAccess.cpp.

{
    pvd::Monitor::shared_pointer ret;
    requester->monitorConnect(pvd::Status(pvd::Status::STATUSTYPE_FATAL, "Not Implemented"),
                              ret, pvd::StructureConstPtr());
    return ret;
}

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.

Reimplemented in epics::pvDatabase::ChannelLocal, epics::pvAccess::RPCChannel, epics::pvAccess::ca::CAChannel, and GWChannel.

Definition at line 57 of file pvAccess.cpp.

{
    return readWrite;
}

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

pure virtual

The name passed to ChannelProvider::createChannel()

Implemented in epics::pvDatabase::ChannelLocal, epics::pvAccess::RPCChannel, epics::pvAccess::ca::CAChannel, BaseChannel, pvas::detail::SharedChannel, and GWChannel.

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

pure virtual

The ChannelRequester passed to ChannelProvider::createChannel()

Exceptions

std::tr1::bad_weak_ptr

Implemented in epics::pvDatabase::ChannelLocal, epics::pvAccess::RPCChannel, epics::pvAccess::ca::CAChannel, BaseChannel, pvas::detail::SharedChannel, and GWChannel.

Channel::ConnectionState epics::pvAccess::Channel::getConnectionState ( )

virtual

Poll the connection state in more detail

Reimplemented in epics::pvDatabase::ChannelLocal, TestPVChannel, epics::pvAccess::RPCChannel, epics::pvAccess::ca::CAChannel, and GWChannel.

Definition at line 47 of file pvAccess.cpp.

{ return CONNECTED; }

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.

Reimplemented in epics::pvAccess::ca::CAChannel.

Definition at line 51 of file pvAccess.cpp.

{
    requester->getDone(pvd::Status(pvd::Status::STATUSTYPE_FATAL, "Not Implemented")
                       ,pvd::FieldConstPtr());
}

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

pure virtual

The ChannelProvider from which this Channel was requested. May never be NULL.

Implemented in epics::pvDatabase::ChannelLocal, epics::pvAccess::RPCChannel, epics::pvAccess::ca::CAChannel, pvas::detail::SharedChannel, BaseChannel, and GWChannel.

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.

Implemented in epics::pvDatabase::ChannelLocal, TestPVChannel, epics::pvAccess::RPCChannel, epics::pvAccess::ca::CAChannel, pvas::detail::SharedChannel, BaseChannel, and GWChannel.

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

virtual

The requester must have a name.

Returns

The requester's name.

Implements epics::pvAccess::Requester.

Reimplemented in epics::pvAccess::RPCChannel, epics::pvDatabase::ChannelLocal, BaseChannel, and GWChannel.

Definition at line 29 of file pvAccess.cpp.

{
    std::tr1::shared_ptr<ChannelRequester> req(getChannelRequester());
    return req ? req->getRequesterName() : std::string("<Destroy'd Channel>");
}

bool epics::pvAccess::Channel::isConnected ( )

virtual

Poll connection state

Reimplemented in epics::pvDatabase::ChannelLocal.

Definition at line 49 of file pvAccess.cpp.

{ return getConnectionState()==CONNECTED; }

void epics::pvAccess::Channel::message ( std::string const &  message, epics::pvData::MessageType  messageType  )

virtual

Reimplemented in epics::pvDatabase::ChannelLocal.

Definition at line 35 of file pvAccess.cpp.

{
    std::tr1::shared_ptr<ChannelRequester> req(getChannelRequester());
    if(req) {
        req->message(message, messageType);
    } else {
        std::cerr<<epics::pvData::getMessageTypeName(messageType)
                 <<": on Destroy'd Channel \""<<getChannelName()
                 <<"\" : "<<message;
    }
}

epics::pvAccess::Channel::POINTER_DEFINITIONS

(

Channel

)

virtual void epics::pvAccess::Channel::printInfo ( )

inlinevirtual

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

Reimplemented in epics::pvDatabase::ChannelLocal.

Definition at line 1126 of file pvAccess.h.

{ printInfo(std::cout); }

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.

Reimplemented in epics::pvDatabase::ChannelLocal, epics::pvAccess::RPCChannel, PDBGroupChannel, epics::pvAccess::ca::CAChannel, PDBSingleChannel, GWChannel, and BaseChannel.

Definition at line 1132 of file pvAccess.h.

{}

Member Data Documentation

const char * epics::pvAccess::Channel::ConnectionStateNames = { "NEVER_CONNECTED", "CONNECTED", "DISCONNECTED", "DESTROYED" }

static

Definition at line 910 of file pvAccess.h.

size_t epics::pvAccess::Channel::num_instances

static

Definition at line 895 of file pvAccess.h.

---

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

• modules/pvAccess/src/client/pv/pvAccess.h
• modules/pvAccess/src/client/pvAccess.cpp