Orocos Real-Time Toolkit  2.9.0
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RTT::base::ChannelElementBase Class Reference

In the data flow implementation, a channel is created by chaining ChannelElementBase objects. More...

#include <rtt/base/ChannelElementBase.hpp>

Inheritance diagram for RTT::base::ChannelElementBase:
RTT::base::ChannelElement< T > RTT::base::MultipleInputsChannelElementBase RTT::base::MultipleOutputsChannelElementBase RTT::internal::SharedConnectionBase RTT::base::MultipleInputsChannelElement< T > RTT::base::MultipleOutputsChannelElement< T > RTT::corba::RemoteChannelElement< T > RTT::internal::ChannelBufferElement< T > RTT::internal::ChannelDataElement< T > RTT::internal::SharedRemoteConnection< T > RTT::mqueue::MQChannelElement< T > RTT::base::MultipleInputsChannelElement< T > RTT::base::MultipleInputsMultipleOutputsChannelElementBase RTT::base::MultipleInputsMultipleOutputsChannelElementBase RTT::base::MultipleOutputsChannelElement< T > RTT::internal::SharedConnection< T > RTT::internal::SharedRemoteConnection< T >

Public Types

typedef boost::intrusive_ptr< ChannelElementBaseshared_ptr
 

Public Member Functions

 ChannelElementBase ()
 A default constructed ChannelElementBase has no input nor output configured. More...
 
virtual ~ChannelElementBase ()
 
template<typename T >
ChannelElement< T > * narrow ()
 Return a pointer to the typed variant of this ChannelElementBase. More...
 
shared_ptr getInput ()
 Returns the current input channel element. More...
 
virtual shared_ptr getInputEndPoint ()
 Returns the first input channel element of this connection. More...
 
shared_ptr getOutput ()
 Returns the next channel element in the channel's propagation direction. More...
 
virtual shared_ptr getOutputEndPoint ()
 Returns the last output channel element of this connection. More...
 
virtual bool connectTo (ChannelElementBase::shared_ptr const &output, bool mandatory=true)
 Connects a new output to this element. More...
 
virtual bool connectFrom (ChannelElementBase::shared_ptr const &input)
 Connects a new input to this element. More...
 
virtual bool connected ()
 Returns true, if this channel element is connected on the input or output side. More...
 
virtual bool signal ()
 Signals that there is new data available on this channel By default, the channel element forwards the call to its output. More...
 
virtual bool signalFrom (ChannelElementBase *)
 Signals that there is new data available on this channel Forwards to signal() unless overwritten in a derived class. More...
 
virtual bool channelReady (ChannelElementBase::shared_ptr const &caller, ConnPolicy const &policy, internal::ConnID *conn_id=0)
 This is called on the output half of a new connection by the connection factory in order to notify the output side of the new connection and check if it is ready to receive data. More...
 
virtual bool inputReady (ChannelElementBase::shared_ptr const &caller)
 This is called by an input port when it is ready to receive data. More...
 
virtual void clear ()
 Clears any data stored by the channel. More...
 
virtual void disconnect (bool forward)
 Performs a disconnection of this channel's endpoints. More...
 
virtual bool disconnect (ChannelElementBase::shared_ptr const &channel, bool forward)
 Performs a disconnection of a single input or output endpoint. More...
 
virtual PortInterfacegetPort () const
 Gets the port this channel element is connected to. More...
 
virtual const ConnPolicygetConnPolicy () const
 Get a pointer to the connection policy used to build this channel element, if available. More...
 
RTT_DEPRECATED void setOutput (const ChannelElementBase::shared_ptr &output)
 
RTT_DEPRECATED void setInput (const ChannelElementBase::shared_ptr &input)
 
virtual bool isRemoteElement () const
 This function may be used to identify, if the current element uses a network transport, to send the data to the next Element in the logical chain. More...
 
virtual std::string getRemoteURI () const
 This function returns the URI of the next channel element in the logical chain. More...
 
virtual std::string getLocalURI () const
 This function return the URI of this element. More...
 
virtual std::string getElementName () const
 Returns the class name of this element. More...
 

Static Public Member Functions

template<typename T >
static ChannelElement< T > * narrow (ChannelElementBase *e)
 Return a pointer to the typed instance of a ChannelElementBase. More...
 

Protected Member Functions

void ref ()
 Increases the reference count. More...
 
void deref ()
 Decreases the reference count, and deletes the object if it is zero. More...
 
virtual bool addOutput (shared_ptr const &output, bool mandatory=true)
 Sets the new output channel element of this element or adds a channel to the outputs list. More...
 
virtual void removeOutput (shared_ptr const &output)
 Remove an output from the outputs list. More...
 
virtual bool addInput (shared_ptr const &input)
 Sets the new input channel element of this element or adds a channel to the inputs list. More...
 
virtual void removeInput (shared_ptr const &input)
 Remove an input from the inputs list. More...
 

Protected Attributes

shared_ptr input
 
shared_ptr output
 
RTT::os::SharedMutex input_lock
 
RTT::os::SharedMutex output_lock
 

Friends

class MultipleInputsChannelElementBase
 
class MultipleOutputsChannelElementBase
 
void RTT_API intrusive_ptr_add_ref (ChannelElementBase *e)
 
void RTT_API intrusive_ptr_release (ChannelElementBase *e)
 

Detailed Description

In the data flow implementation, a channel is created by chaining ChannelElementBase objects.

ChannelElementBase objects are refcounted. In the chain, an element maintains the refcount for its successor, and holds a simple pointer to its predecessor.

Definition at line 65 of file ChannelElementBase.hpp.

Member Typedef Documentation

Definition at line 68 of file ChannelElementBase.hpp.

Constructor & Destructor Documentation

ChannelElementBase::ChannelElementBase ( )

A default constructed ChannelElementBase has no input nor output configured.

The only way to set an input or output is to use connectTo() or connectFrom().

Definition at line 47 of file ChannelInterface.cpp.

References ORO_ATOMIC_SETUP().

ChannelElementBase::~ChannelElementBase ( )
virtual

Definition at line 52 of file ChannelInterface.cpp.

References ORO_ATOMIC_CLEANUP().

Member Function Documentation

bool ChannelElementBase::addInput ( shared_ptr const &  input)
protectedvirtual

Sets the new input channel element of this element or adds a channel to the inputs list.

Parameters
inputthe previous element in chain.
Returns
true if the input was set or false if this element does not support multiple inputs and the input is already set.

Reimplemented in RTT::base::MultipleInputsChannelElementBase.

Definition at line 106 of file ChannelInterface.cpp.

References input, and input_lock.

Referenced by connectFrom().

bool ChannelElementBase::addOutput ( shared_ptr const &  output,
bool  mandatory = true 
)
protectedvirtual

Sets the new output channel element of this element or adds a channel to the outputs list.

Parameters
outputthe next element in chain.
mandatorywhether the added output is mandatory for a write to succeed
Returns
true if the output was set or false if this element does not support multiple outputs and the output is already set.

Reimplemented in RTT::base::MultipleOutputsChannelElementBase.

Definition at line 79 of file ChannelInterface.cpp.

References output, and output_lock.

Referenced by connectTo().

bool ChannelElementBase::channelReady ( ChannelElementBase::shared_ptr const &  caller,
ConnPolicy const &  policy,
internal::ConnID conn_id = 0 
)
virtual

This is called on the output half of a new connection by the connection factory in order to notify the output side of the new connection and check if it is ready to receive data.

Each channel element has the responsibility to pass this notification on to the next, in the direction of the input. The ConnOutputEndPoint then calls back the inputReady() method in reverse direction to notify the output that the connection was successfully established.

Returns
false if a fatal connection failure was encountered and the channel needs to be destroyed.

Reimplemented in RTT::corba::RemoteChannelElement< T >, RTT::base::MultipleOutputsChannelElementBase, and RTT::internal::ConnOutputEndpoint< T >.

Definition at line 169 of file ChannelInterface.cpp.

References getInput(), getOutput(), input, inputReady(), and output.

Referenced by RTT::corba::RemoteChannelElement< T >::channelReady().

void ChannelElementBase::clear ( )
virtual

Clears any data stored by the channel.

It means that ChannelElement::read() will return false afterwards (provided that no new data has been written on the meantime of course)

By default, the channel element forwards the calls to its input

Reimplemented in RTT::base::MultipleInputsChannelElementBase, RTT::internal::SharedConnection< T >, RTT::internal::ChannelBufferElement< T >, and RTT::internal::ChannelDataElement< T >.

Definition at line 188 of file ChannelInterface.cpp.

References getInput(), and input.

Referenced by RTT::internal::ChannelDataElement< T >::clear(), RTT::internal::ChannelBufferElement< T >::clear(), and RTT::internal::SharedConnection< T >::clear().

bool ChannelElementBase::connected ( )
virtual

Returns true, if this channel element is connected on the input or output side.

Reimplemented in RTT::base::MultipleInputsMultipleOutputsChannelElementBase, RTT::base::MultipleOutputsChannelElementBase, and RTT::base::MultipleInputsChannelElementBase.

Definition at line 123 of file ChannelInterface.cpp.

References input, input_lock, output, and output_lock.

bool ChannelElementBase::connectFrom ( ChannelElementBase::shared_ptr const &  input)
virtual

Connects a new input to this element.

Parameters
inputthe previous element in chain.

Definition at line 96 of file ChannelInterface.cpp.

References addInput(), and removeInput().

bool ChannelElementBase::connectTo ( ChannelElementBase::shared_ptr const &  output,
bool  mandatory = true 
)
virtual

Connects a new output to this element.

Parameters
outputthe next element in chain.
mandatorywhether the added output is mandatory for a write operation to succeed

Definition at line 69 of file ChannelInterface.cpp.

References addOutput(), and removeOutput().

Referenced by RTT::internal::ConnFactory::buildChannelInput(), RTT::internal::ConnFactory::buildChannelOutput(), RTT::internal::ConnFactory::buildSharedConnection(), and RTT::internal::ConnFactory::createAndCheckSharedConnection().

void ChannelElementBase::deref ( )
protected

Decreases the reference count, and deletes the object if it is zero.

Definition at line 467 of file ChannelInterface.cpp.

References oro_atomic_dec_and_test().

Referenced by RTT::corba::RemoteChannelElement< T >::_remove_ref().

void ChannelElementBase::disconnect ( bool  forward)
virtual

Performs a disconnection of this channel's endpoints.

If forward is true, then the disconnection is initiated by the input endpoint. Otherwise, it has been initiated by the output endpoint.

Definition at line 130 of file ChannelInterface.cpp.

References getInput(), getOutput(), input, output, removeInput(), and removeOutput().

Referenced by RTT::corba::RemoteChannelElement< T >::disconnect(), RTT::base::MultipleInputsChannelElementBase::disconnect(), RTT::base::MultipleOutputsChannelElementBase::disconnect(), RTT::internal::ConnectionManager::eraseConnection(), and RTT::corba::RemoteChannelElement< T >::remoteDisconnect().

virtual bool RTT::base::ChannelElementBase::disconnect ( ChannelElementBase::shared_ptr const &  channel,
bool  forward 
)
virtual

Performs a disconnection of a single input or output endpoint.

If forward is true, then the disconnection is initiated by the input endpoint and channel must be a connected input. Otherwise, it has been initiated by the output endpoint and channel must be a connected output. The disconnect call is only forwarded to the opposite side of the channel element after the last input/output element on either side has been removed.

The ChannelElementBase implementation ignores the given channel and disconnects unconditinally.

Reimplemented in RTT::base::MultipleInputsMultipleOutputsChannelElementBase, RTT::base::MultipleOutputsChannelElementBase, RTT::base::MultipleInputsChannelElementBase, RTT::corba::RemoteChannelElement< T >, RTT::internal::ConnOutputEndpoint< T >, and RTT::internal::ConnInputEndpoint< T >.

const ConnPolicy * ChannelElementBase::getConnPolicy ( ) const
virtual

Get a pointer to the connection policy used to build this channel element, if available.

This method will be overwritten for data and buffer elements.

Returns
null if there is no ConnPolicy associated with this element, a pointer to an instance of ConnPolicy otherwise.

Reimplemented in RTT::internal::ChannelBufferElement< T >, RTT::internal::ChannelDataElement< T >, and RTT::internal::SharedConnectionBase.

Definition at line 207 of file ChannelInterface.cpp.

Referenced by RTT::internal::ConnFactory::buildChannelInput(), and RTT::internal::ConnFactory::buildChannelOutput().

std::string ChannelElementBase::getElementName ( ) const
virtual

Returns the class name of this element.

This is primary useful for special case handling in the connection tracking.

Returns
The name of the class of the ChannelElement

Reimplemented in RTT::corba::RemoteChannelElement< T >, RTT::mqueue::MQChannelElement< T >, RTT::internal::ConnOutputEndpoint< T >, RTT::internal::ChannelBufferElement< T >, RTT::internal::ConnInputEndpoint< T >, and RTT::internal::ChannelDataElement< T >.

Definition at line 227 of file ChannelInterface.cpp.

ChannelElementBase::shared_ptr ChannelElementBase::getInput ( )

Returns the current input channel element.

This will only return a valid channel element if another element has received this object as an argument to connectTo().

Returns

Definition at line 57 of file ChannelInterface.cpp.

References input, and input_lock.

Referenced by channelReady(), clear(), disconnect(), RTT::base::ChannelElement< T >::getInput(), getInputEndPoint(), RTT::mqueue::MQChannelElement< T >::getLocalURI(), and RTT::corba::RemoteChannelElement< T >::getLocalURI().

ChannelElementBase::shared_ptr ChannelElementBase::getInputEndPoint ( )
virtual

Returns the first input channel element of this connection.

Will return the channel element the furthest away from the input port, or this if none.

Returns
getInput() ? getInput()->getInputEndPoint() : this

Reimplemented in RTT::internal::ConnInputEndpoint< T >.

Definition at line 157 of file ChannelInterface.cpp.

References getInput(), and input.

std::string ChannelElementBase::getLocalURI ( ) const
virtual

This function return the URI of this element.

The URI must be unique.

Returns
URI of this element.

Reimplemented in RTT::corba::RemoteChannelElement< T >, and RTT::mqueue::MQChannelElement< T >.

Definition at line 223 of file ChannelInterface.cpp.

Referenced by RTT::mqueue::MQChannelElement< T >::getLocalURI(), and RTT::corba::RemoteChannelElement< T >::getLocalURI().

ChannelElementBase::shared_ptr ChannelElementBase::getOutput ( )
ChannelElementBase::shared_ptr ChannelElementBase::getOutputEndPoint ( )
virtual

Returns the last output channel element of this connection.

Will return the channel element the furthest away from the output port, or this if none.

Returns
getOutput() ? getOutput()->getOutputEndPoint() : this

Reimplemented in RTT::internal::ConnOutputEndpoint< T >.

Definition at line 163 of file ChannelInterface.cpp.

References getOutput(), and output.

Referenced by RTT::corba::CDataFlowInterface_i::deregisterChannel().

PortInterface * ChannelElementBase::getPort ( ) const
virtual

Gets the port this channel element is connected to.

Returns
null if no port is connected to this element, the port (or a proxy representing the port) otherwise.

Reimplemented in RTT::internal::ConnOutputEndpoint< T >, and RTT::internal::ConnInputEndpoint< T >.

Definition at line 203 of file ChannelInterface.cpp.

std::string ChannelElementBase::getRemoteURI ( ) const
virtual

This function returns the URI of the next channel element in the logical chain.

The URI must be unique. E.g: In the local case output->getLocalURI() In the remote case the URI of the remote channel element.

Returns
URI of the next element.

Reimplemented in RTT::corba::RemoteChannelElement< T >, and RTT::mqueue::MQChannelElement< T >.

Definition at line 215 of file ChannelInterface.cpp.

References output.

Referenced by RTT::mqueue::MQChannelElement< T >::getRemoteURI(), and RTT::corba::RemoteChannelElement< T >::getRemoteURI().

virtual bool RTT::base::ChannelElementBase::inputReady ( ChannelElementBase::shared_ptr const &  caller)
virtual

This is called by an input port when it is ready to receive data.

Each channel element has the responsibility to pass this notification on to the next, in the direction of the output.

Returns
false if a fatal connection failure was encountered and the channel needs to be destroyed.

Reimplemented in RTT::corba::RemoteChannelElement< T >, RTT::base::MultipleInputsChannelElementBase, RTT::mqueue::MQChannelElement< T >, and RTT::internal::ConnInputEndpoint< T >.

Referenced by channelReady().

bool ChannelElementBase::isRemoteElement ( ) const
virtual

This function may be used to identify, if the current element uses a network transport, to send the data to the next Element in the logical chain.

Returns
true if a network transport is used.

Reimplemented in RTT::corba::RemoteChannelElement< T >, and RTT::mqueue::MQChannelElement< T >.

Definition at line 211 of file ChannelInterface.cpp.

template<typename T >
static ChannelElement<T>* RTT::base::ChannelElementBase::narrow ( ChannelElementBase e)
inlinestatic

Return a pointer to the typed instance of a ChannelElementBase.

Definition at line 101 of file ChannelElementBase.hpp.

Referenced by RTT::base::MultipleInputsChannelElement< T >::read().

template<typename T >
ChannelElement<T>* RTT::base::ChannelElementBase::narrow ( )
inline

Return a pointer to the typed variant of this ChannelElementBase.

Definition at line 109 of file ChannelElementBase.hpp.

void ChannelElementBase::ref ( )
protected
void ChannelElementBase::removeInput ( shared_ptr const &  input)
protectedvirtual

Remove an input from the inputs list.

Parameters
inputthe element to be removed, or null to remove unconditionally

Reimplemented in RTT::base::MultipleInputsChannelElementBase, and RTT::base::MultipleInputsChannelElement< T >.

Definition at line 115 of file ChannelInterface.cpp.

References input_lock.

Referenced by connectFrom(), disconnect(), and RTT::base::MultipleInputsChannelElementBase::disconnect().

void ChannelElementBase::removeOutput ( shared_ptr const &  output)
protectedvirtual

Remove an output from the outputs list.

Parameters
outputthe element to be removed, or null to remove unconditionally

Reimplemented in RTT::base::MultipleOutputsChannelElementBase.

Definition at line 88 of file ChannelInterface.cpp.

References output_lock.

Referenced by connectTo(), and disconnect().

RTT_DEPRECATED void RTT::base::ChannelElementBase::setInput ( const ChannelElementBase::shared_ptr input)
inline

Definition at line 244 of file ChannelElementBase.hpp.

RTT_DEPRECATED void RTT::base::ChannelElementBase::setOutput ( const ChannelElementBase::shared_ptr output)
inline

Definition at line 238 of file ChannelElementBase.hpp.

bool ChannelElementBase::signal ( )
virtual

Signals that there is new data available on this channel By default, the channel element forwards the call to its output.

Returns
false if an error occured that requires the channel to be invalidated. In no ways it indicates that the sample has been received by the other side of the channel.

Reimplemented in RTT::base::MultipleOutputsChannelElementBase, RTT::internal::ConnOutputEndpoint< T >, RTT::mqueue::MQChannelElement< T >, and RTT::corba::RemoteChannelElement< T >.

Definition at line 195 of file ChannelInterface.cpp.

References getOutput(), and output.

Referenced by RTT::corba::RemoteChannelElement< T >::remoteSignal(), RTT::corba::RemoteChannelElement< T >::signal(), RTT::base::MultipleOutputsChannelElementBase::signal(), RTT::base::MultipleInputsChannelElementBase::signalFrom(), and RTT::internal::ChannelDataElement< T >::write().

virtual bool RTT::base::ChannelElementBase::signalFrom ( ChannelElementBase )
inlinevirtual

Signals that there is new data available on this channel Forwards to signal() unless overwritten in a derived class.

Reimplemented in RTT::base::MultipleInputsChannelElementBase.

Definition at line 173 of file ChannelElementBase.hpp.

Friends And Related Function Documentation

void RTT_API intrusive_ptr_add_ref ( ChannelElementBase e)
friend
void RTT_API intrusive_ptr_release ( ChannelElementBase e)
friend
friend class MultipleInputsChannelElementBase
friend

Definition at line 289 of file ChannelElementBase.hpp.

friend class MultipleOutputsChannelElementBase
friend

Definition at line 290 of file ChannelElementBase.hpp.

Member Data Documentation

shared_ptr RTT::base::ChannelElementBase::input
protected
RTT::os::SharedMutex RTT::base::ChannelElementBase::input_lock
mutableprotected

Definition at line 79 of file ChannelElementBase.hpp.

Referenced by addInput(), connected(), getInput(), and removeInput().

shared_ptr RTT::base::ChannelElementBase::output
protected
RTT::os::SharedMutex RTT::base::ChannelElementBase::output_lock
mutableprotected

Definition at line 80 of file ChannelElementBase.hpp.

Referenced by addOutput(), connected(), getOutput(), and removeOutput().


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