dds::sub::GenerationCount Class Reference

Class to hold sample GenerationCount information and is part of dds::sub::SampleInfo. More...

#include "GenerationCount.hpp"

Inherits dds::core::Value< D >.

Public Member Functions
int32_t	disposed () const
int32_t	no_writers () const
bool	operator!= (const Value &other) const
D *	operator-> ()
const D *	operator-> () const
bool	operator== (const Value &other) const

Detailed Description

Class to hold sample GenerationCount information and is part of dds::sub::SampleInfo.

Generations A generation is defined as: ‘the number of times an instance has become alive (with instance_state==ALIVE) at the time the sample was received’. Note that the generation counters are initialized to zero when a DataReader first detects a never-seen-before instance.

For each instance the middleware internally maintains two counts: the disposed_generation_count and no_writers_generation_count, relative to each DataReader:

Two types of generations are distinguished: disposed_generation_count and no_writers_generation_count.

• The disposed_generation_count and no_writers_generation_count are initialized to zero when the DataReader first detects the presence of a never-seen-before instance.
• The disposed_generation_count is incremented each time the instance_state of the corresponding instance changes from not_alive_disposed to alive.
• The no_writers_generation_count is incremented each time the instance_state of the corresponding instance changes from not_alive_no_writers to alive.

The disposed_generation_count and no_writers_generation_count associated with the SampleInfo capture a snapshot of the corresponding counters at the time the sample was received.

See also

SampleInfo for more information

Definition at line 63 of file GenerationCount.hpp.

Member Function Documentation

disposed()

int32_t dds::sub::GenerationCount::disposed

(

)

const

Gets the disposed_generation_count.

The disposed_generation_count is initialized at zero and is incremented each time the instance_state, of the corresponding instance, changes from not_alive_disposed to alive.

Returns

the disposed_generation_count

no_writers()

int32_t dds::sub::GenerationCount::no_writers ( ) const

inline

Gets the no_writers_generation_count.

The no_writers_generation_count is initialized at zero and is incremented each time the instance_state, of the corresponding instance, changes from not_alive_no_writers to alive.

Returns

the no_writers_generation_count

operator!=()

template<typename D >

bool dds::core::Value< D >::operator!= ( const Value< D > &  other ) const

inherited

Compare this Value with another Value

Parameters

other

Value

Returns

true if not equal

operator->() [1/2]

template<typename D >

D* dds::core::Value< D >::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 Value and on all its subclasses as follows:

my_dds_value.standard_function();
my_dds_value->vendor_specific_extension();

Returns

a reference to delegate.

operator->() [2/2]

template<typename D >

const D* dds::core::Value< D >::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 Value and on all its subclasses as follows:

my_dds_value.standard_function();
my_dds_value->vendor_specific_extension();

Returns

a reference to delegate.

operator==()

template<typename D >

bool dds::core::Value< D >::operator== ( const Value< D > &  other ) const

inherited

Compare this Value with another Value

Parameters

other

Value

Returns

true if equal

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

• dds/sub/GenerationCount.hpp