ReadCondition objects are conditions specifically dedicated to read operations and attached to one DataReader. More...

#include "ReadCondition.hpp"

Inheritance diagram for dds::sub::cond::ReadCondition:

Public Member Functions
	ReadCondition (const dds::sub::AnyDataReader &dr, const dds::sub::status::DataState &status)

template<typename FUN >
	ReadCondition (const dds::sub::AnyDataReader &dr, const dds::sub::status::DataState &status, FUN &functor)

template<typename FUN >
	ReadCondition (const dds::sub::AnyDataReader &dr, const dds::sub::status::DataState &status, const FUN &functor)

const dds::sub::AnyDataReader &	data_reader () const

void	dispatch ()

template<typename Functor >
void	handler (Functor &func)

template<typename Functor >
void	handler (const Functor &func)

bool	is_nil () const

template<typename R >
bool	operator!= (const R &ref) const

bool	operator!= (const null_type nil) const

DELEGATE *	operator-> ()

const DELEGATE *	operator-> () const

template<typename R >
bool	operator== (const R &ref) const

bool	operator== (const null_type) const

void	reset_handler ()

const dds::sub::status::DataState	state_filter () const

bool	trigger_value () const

Detailed Description

ReadCondition objects are conditions specifically dedicated to read operations and attached to one DataReader.

ReadCondition objects allow an application to specify the data samples it is interested in (by specifying the desired sample states, view states, and instance states). (See the parameter definitions for DataReader's read/take operations.) This allows the middle-ware to enable the condition only when suitable information is available. They are to be used in conjunction with a WaitSet as normal conditions. More than one ReadCondition may be attached to the same DataReader.

See the WaitSet examples for some examples.
Although the WaitSet examples use the StatusCondition, the basic usage of this Condition with a WaitSet is the same.

See also: dds::core::cond::Condition; Status concept; WaitSet concept; Subscription concept; WaitSet examples

Definition at line 63 of file ReadCondition.hpp.

Constructor & Destructor Documentation

◆ ReadCondition() [1/3]

dds::sub::cond::ReadCondition::ReadCondition	(	const dds::sub::AnyDataReader &	dr,
		const dds::sub::status::DataState &	status
	)

Create a dds::sub::cond::ReadCondition associated with a DataReader.

The ReadCondition can then be added to a dds::core::cond::WaitSet so that the application can wait for specific status changes that affect the Entity.

State Masks.
The result of the ReadCondition depends on the selection of samples determined by three masks:

DataState::sample_state() is the mask, which selects only those samples with the desired sample states SampleState::read(), SampleState::not_read() or SampleState::any().
DataState::view_state() is the mask, which selects only those samples with the desired view states ViewState::new_view(), ViewState::not_new_view() or ViewState::any().
DataState::instance_state() is the mask, which selects only those samples with the desired view states InstanceState::alive(), InstanceState::not_alive_disposed(), InstanceState::not_alive_no_writers(), InstanceState::not_alive_mask() or InstanceState::any(). See also Status Concept.

Parameters

dr	The DataReader to associate with the ReadCondition.
status	A mask, which selects only those samples with the desired sample/view/instance states.

Exceptions

dds::core::Exception

Definition at line 44 of file ReadConditionImpl.hpp.

◆ ReadCondition() [2/3]

template<typename FUN >

dds::sub::cond::ReadCondition::ReadCondition	(	const dds::sub::AnyDataReader &	dr,
		const dds::sub::status::DataState &	status,
		FUN &	functor
	)

Create a dds::sub::cond::ReadCondition associated with a DataReader.

The ReadCondition can then be added to a dds::core::cond::WaitSet so that the application can wait for specific status changes that affect the Entity.

The supplied functor will be called when this ReadCondition is triggered and either the inherited dds::core::cond::Condition::dispatch() is called or the dds::core::cond::WaitSet::dispatch() on the WaitSet to which this ReadCondition is attached to.

See State mask info.

Parameters

dr	The DataReader to associate with the ReadCondition.
status	A mask, which selects only those samples with the desired sample/view/instance states.

Template Parameters

functor The functor to be called when the ReadCondition triggers.

Exceptions

dds::core::Exception

◆ ReadCondition() [3/3]

template<typename FUN >

dds::sub::cond::ReadCondition::ReadCondition	(	const dds::sub::AnyDataReader &	dr,
		const dds::sub::status::DataState &	status,
		const FUN &	functor
	)

Create a dds::sub::cond::ReadCondition associated with a DataReader.

The ReadCondition can then be added to a dds::core::cond::WaitSet so that the application can wait for specific status changes that affect the Entity.

The supplied functor will be called when this ReadCondition is triggered and either the inherited dds::core::cond::Condition::dispatch() is called or the dds::core::cond::WaitSet::dispatch() on the WaitSet to which this ReadCondition is attached to.

See State mask info.

Parameters

dr	The DataReader to associate with the ReadCondition.
status	A mask, which selects only those samples with the desired sample/view/instance states.

Template Parameters

functor The functor to be called when the ReadCondition triggers.

Exceptions

dds::core::Exception

Member Function Documentation

◆ data_reader()

const AnyDataReader & dds::sub::cond::ReadCondition::data_reader ( ) const

This operation returns the DataReader associated with the ReadCondition.

Note that there is exactly one DataReader associated with each ReadCondition.

Returns: dds::sub::AnyDataReader The associated DataReader

Exceptions

dds::core::Exception

Definition at line 94 of file ReadConditionImpl.hpp.

◆ dispatch()

void dds::core::cond::Condition::dispatch ( )

inherited

Dispatches the functor that have been registered with the Condition.

The Condition has to have been triggered for the functor will be called by this function.

Returns: void

Exceptions

dds::core::Exception

Definition at line 76 of file ConditionImpl.hpp.

◆ handler() [1/2]

template<typename Functor >

void dds::core::cond::Condition::handler ( Functor & func )

inherited

Registers a functor as custom handler with this Condition.

The supplied functor will be called when this Condition is triggered and either the dds::core::cond::Condition::dispatch() is called or the dds::core::cond::WaitSet::dispatch() on the WaitSet to which this Condition is attached to.

Template Parameters

Functor The functor to be called when the StatusCondition triggers.

Returns: void

Exceptions

dds::core::Exception

◆ handler() [2/2]

template<typename Functor >

void dds::core::cond::Condition::handler ( const Functor & func )

inherited

Registers a functor as custom handler with this Condition.

The supplied functor will be called when this Condition is triggered and either the dds::core::cond::Condition::dispatch() is called or the dds::core::cond::WaitSet::dispatch() on the WaitSet to which this Condition is attached to.

Template Parameters

Functor The functor to be called when the StatusCondition triggers.

Returns: void

Exceptions

dds::core::Exception

◆ is_nil()

template<typename DELEGATE >

bool dds::core::Reference< DELEGATE >::is_nil ( ) const

inherited

Check if the referenced object is nil.

In other words, check if the reference is pointing to a null object.

Returns: true if the referenced object is null.

Definition at line 143 of file ReferenceImpl.hpp.

◆ operator!=() [1/2]

template<typename DELEGATE >

template<typename R >

bool dds::core::Reference< DELEGATE >::operator!= ( const R & ref ) const

inherited

Compares two Reference objects and returns true if they are not equal.

Inequality is based on the referential inequality of the object being pointed to.

Parameters

ref	the other Reference object

Returns: true when not equal

Definition at line 100 of file ReferenceImpl.hpp.

◆ operator!=() [2/2]

template<typename DELEGATE >

bool dds::core::Reference< DELEGATE >::operator!= ( const null_type nil ) const

inherited

Special operator!= used to check if this reference object does not equal the dds::core::null reference.

The non-null-check can be done like this:

if (r != dds::core::null) {
   // Use the dds reference object r
}

Returns: true if this reference is not null.

Definition at line 157 of file ReferenceImpl.hpp.

◆ operator->() [1/2]

template<typename DELEGATE >

DELEGATE * dds::core::Reference< DELEGATE >::operator-> ( )

inherited

The operator->() is provided to be able to directly invoke functions on the delegate.

The decision to provide direct access to the delegate was motivated by the need for providing a way that was not invasive with respect to the CXXDDS API and yet would allow for vendor-specific extension. Thus vendor-specific extensions can be invoked on the Reference and on all its subclasses as follows:

my_dds_entity.standard_function();

my_dds_entity->vendor_specific_extension();

Returns: a reference to delegate.

Definition at line 180 of file ReferenceImpl.hpp.

◆ operator->() [2/2]

template<typename DELEGATE >

const DELEGATE * dds::core::Reference< DELEGATE >::operator-> ( ) const

inherited

The operator->() is provided to be able to directly invoke functions on the delegate.

The decision to provide direct access to the delegate was motivated by the need for providing a way that was not invasive with respect to the CXXDDS API and yet would allow for vendor-specific extension. Thus vendor-specific extensions can be invoked on the Reference and on all its subclasses as follows:

my_dds_entity.standard_function();

my_dds_entity->vendor_specific_extension();

Returns: a reference to delegate.

Definition at line 188 of file ReferenceImpl.hpp.

◆ operator==() [1/2]

template<typename DELEGATE >

template<typename R >

bool dds::core::Reference< DELEGATE >::operator== ( const R & ref ) const

inherited

Compares two Reference objects and returns true if they are equal.

Equality is based on the referential equality of the object being pointed.

Parameters

ref	the other Reference object

Returns: true when equal

Definition at line 83 of file ReferenceImpl.hpp.

◆ operator==() [2/2]

template<typename DELEGATE >

bool dds::core::Reference< DELEGATE >::operator== ( const null_type ) const

inherited

Special operator== used to check if this reference object equals the dds::core::null reference.

The null-check can be done like this:

if (r == dds::core::null) {
   // Do not use the dds reference object r in its current state
}

Returns: true if this reference is null.

Definition at line 150 of file ReferenceImpl.hpp.

◆ reset_handler()

void dds::core::cond::Condition::reset_handler ( )

inherited

Resets the handler for this Condition.

After the invocation of this function no handler will be registered with this Condition.

Returns: void

Exceptions

dds::core::Exception

Definition at line 69 of file ConditionImpl.hpp.

◆ state_filter()

const dds::sub::status::DataState dds::sub::cond::ReadCondition::state_filter ( ) const

This operation returns the set of data-states that are taken into account to determine the trigger_value of the ReadCondition.

These are data-states specified when the ReadCondition was created.

Returns: dds::sub::status::DataState The data state.

Exceptions

dds::core::Exception

Definition at line 87 of file ReadConditionImpl.hpp.

◆ trigger_value()

bool dds::core::cond::Condition::trigger_value ( ) const

inherited

This operation retrieves the trigger_value of the Condition.

A Condition has a trigger_value that can be TRUE or FALSE and is set by the Data Distribution Service (except a GuardCondition). This operation returns the trigger_value of the Condition.

Returns: bool The boolean value to which the Condition is set.

Exceptions

dds::core::Exception

Definition at line 83 of file ConditionImpl.hpp.

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

include/dcps/C++/isocpp2/dds/sub/cond/ReadCondition.hpp
include/dcps/C++/isocpp2/dds/sub/cond/detail/ReadConditionImpl.hpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ ReadCondition() [1/3]

◆ ReadCondition() [2/3]

◆ ReadCondition() [3/3]

Member Function Documentation

◆ data_reader()

◆ dispatch()

◆ handler() [1/2]

◆ handler() [2/2]

◆ is_nil()

◆ operator!=() [1/2]

◆ operator!=() [2/2]

◆ operator->() [1/2]

◆ operator->() [2/2]

◆ operator==() [1/2]

◆ operator==() [2/2]

◆ reset_handler()

◆ state_filter()

◆ trigger_value()