Allows receiving requests and sending replies. More...

Public Types
typedef TReq	Request
	The request type. More...

typedef TRep	Reply
	The reply type. More...

typedef dds_type_traits< TRep >::DataWriter	ReplyDataWriter
	The typed DataWriter for type `TRep`. More...

typedef dds_type_traits< TReq >::DataReader	RequestDataReader
	The typed DataReader for type `TReq`. More...

Public Member Functions
	Replier (DDSDomainParticipant *participant, const std::string &service_name)
	Creates a Replier with the minimum set of parameters. More...

	Replier (const ReplierParams< TReq, TRep > &params)
	Creates a Replier with parameters. More...

virtual	~Replier ()
	Releases the internal entities created by this Replier. More...

template<typename URep >
void	send_reply (const URep &reply, const SampleIdentity_t &related_request_id)
	Sends a reply for a previous request. More...

template<typename URep >
void	send_reply (WriteSample< URep > &reply, const SampleIdentity_t &related_request_id)
	Sends a reply for a previous request. More...

template<typename URep >
void	send_reply (WriteSampleRef< URep > &reply, const SampleIdentity_t &related_request_id)
	Sends a reply for a previous request using a SampleRef. More...

bool	receive_request (connext::Sample< TReq > &request, const DDS_Duration_t &max_wait)
	Waits for a request and copies its contents into a Sample. More...

bool	receive_request (connext::SampleRef< TReq > request, const DDS_Duration_t &max_wait)
	Waits for a request and copies its contents into a SampleRef. More...

LoanedSamplesType	receive_requests (const DDS_Duration_t &max_wait)
	Waits for multiple requests and provides a loaned container to access them. More...

LoanedSamplesType	receive_requests (int min_request_count, int max_request_count, const DDS_Duration_t &max_wait)
	Waits for multiple requests and provides a loaned container to access them. More...

bool	wait_for_requests (const DDS_Duration_t &max_wait)
	Waits for requests. More...

bool	wait_for_requests (int min_count, const DDS_Duration_t &max_wait)
	Waits for requests. More...

bool	take_request (connext::Sample< TReq > &request)
	Copies the contents of a request into a Sample. More...

bool	take_request (connext::SampleRef< TReq > request)
	Copies the contents of a request into a SampleRef. More...

LoanedSamplesType	take_requests (int max_samples=DDS_LENGTH_UNLIMITED)
	Provides a loaned container to access the existing requests. More...

bool	read_request (connext::Sample< TReq > &request)
	Copies the contents of a request into a Sample. More...

bool	read_request (connext::SampleRef< TReq > request)
	Copies the contents of a request into a SampleRef. More...

LoanedSamplesType	read_requests (int max_samples=DDS_LENGTH_UNLIMITED)
	Provides a loaned container to access the existing requests. More...

RequestDataReader *	get_request_datareader () const
	Retrieves the underlying DDSDataReader. More...

ReplyDataWriter *	get_reply_datawriter () const
	Retrieves the underlying DDSDataWriter. More...

Detailed Description

template<typename TReq, typename TRep>
class connext::Replier< TReq, TRep >

Allows receiving requests and sending replies.

A Replier is an entity with two associated topics: a request topic and a reply topic. It can receive requests by subscribing to the request topic and can send replies to those requests by publishing the reply topic.

Valid types for these topics (TReq and TRep) are: those generated by rtiddsgen, the DDS built-in types, and DDS_DynamicData. See Creating a Replier.

A Replier has four main types of operations:

Waiting for requests to be received from the middleware
Getting those requests
Receiving requests (a convenience operation that is a combination of waiting and getting in a single operation)
Sending a reply for a previously received request (i.e., publishing a reply sample on the reply topic with special meta-data so that the orignal Requester can identify it)

For multi-reply scenarios in which a connext::Replier generates more than one reply for a request, the connext::Replier should mark all the intermediate replies (all but the last) using the DDS_INTERMEDIATE_REPLY_SEQUENCE_SAMPLE flag in DDS_WriteParams_t::flag.

Much like a Requester, a Replier has an associated DDSDomainParticipant, which can be shared with other Repliers or RTI Connext routines. All the other entities required for the request-reply interaction, including a DDSDataWriter for writing replies and a DDSDataReader for reading requests, are automatically created when the Replier is constructed.

Quality of Service for the underlying DataWriter and DataReader can be configured (see connext::RequesterParams::qos_profile). By default, they are created with DDS_RELIABLE_RELIABILITY_QOS. The exact default configuration is described here: Configuring Request-Reply QoS profiles

There are several ways to use a Replier:

A thread receives requests and then dispatches them. If the computation of a reply is a simple operation, consider using a connext::SimpleReplier instead of a Replier.
Polling without waiting, using take_requests(int) directly.
Using a connext::ReplierListener to get notified and get the requests within the callback.

Template Parameters

TReq	The data type for the request topic
TRep	The data type for the reply topic

See also: connext::Requester; Request-Reply Examples; Basic Replier example

Member Typedef Documentation

◆ Request

template<typename TReq , typename TRep >

typedef TReq connext::Replier< TReq, TRep >::Request

The request type.

◆ Reply

template<typename TReq , typename TRep >

typedef TRep connext::Replier< TReq, TRep >::Reply

The reply type.

◆ ReplyDataWriter

template<typename TReq , typename TRep >

typedef dds_type_traits<TRep>::DataWriter connext::Replier< TReq, TRep >::ReplyDataWriter

The typed DataWriter for type TRep.

◆ RequestDataReader

template<typename TReq , typename TRep >

typedef dds_type_traits<TReq>::DataReader connext::Replier< TReq, TRep >::RequestDataReader

The typed DataReader for type TReq.

Constructor & Destructor Documentation

◆ Replier() [1/2]

template<typename TReq , typename TRep >

connext::Replier< TReq, TRep >::Replier	(	DDSDomainParticipant *	participant,
		const std::string &	service_name
	)

Creates a Replier with the minimum set of parameters.

Parameters

participant	The DomainParticipant that this Replier uses to join a domain.
service_name	The service name. See connext::ReplierParams::service_name

Exceptions

One	of the RTI Connext Exceptions ‍

◆ Replier() [2/2]

template<typename TReq , typename TRep >

connext::Replier< TReq, TRep >::Replier ( const ReplierParams< TReq, TRep > & params )

explicit

Creates a Replier with parameters.

Parameters

params All the parameters that configure this Replier

Exceptions

One	of the RTI Connext Exceptions ‍

See also: connext::ReplierParams; Creating a Replier

◆ ~Replier()

template<typename TReq , typename TRep >

connext::Replier< TReq, TRep >::~Replier

virtual

Releases the internal entities created by this Replier.

Among other internal resources, it deletes the Replier's underlying DataReader and DataWriter.

See also: DDSSubscriber::delete_datareader; DDSPublisher::delete_datawriter

Member Function Documentation

◆ send_reply() [1/3]

template<typename TReq , typename TRep >

template<typename URep >

void connext::Replier< TReq, TRep >::send_reply	(	const URep &	reply,
		const SampleIdentity_t &	related_request_id
	)

Sends a reply for a previous request.

The related request identity can be retrieved from an existing request sample (connext::Sample).

Parameters

reply	The reply to be sent.
related_request_id	The identity of a previously received request

Exceptions

One	of the RTI Connext Exceptions ‍

See also: connext::Sample::identity(); receive_request(Sample<TReq>&, const Duration_t&); receive_requests(int, int, const Duration_t&); take_request(Sample<TReq>&); take_requests(int); Basic Replier example

◆ send_reply() [2/3]

template<typename TReq , typename TRep >

template<typename URep >

void connext::Replier< TReq, TRep >::send_reply	(	WriteSample< URep > &	reply,
		const SampleIdentity_t &	related_request_id
	)

Sends a reply for a previous request.

Allows you to set custom parameters for writing a reply.

Contrary to the connext::Requester, where retrieving the sample identity for correlation is common, on the Replier side using a WriteSample is only necessary when the default write parameters need to be overridden, and send_reply(const URep&, const SampleIdentity_t&) may be used if that is not necessary.

One reason to override the default write parameters is a multi-reply scenario in which a connext::Replier generates more than one reply for a request. In this case, all the intermediate replies (all but the last) should be marked with the DDS_INTERMEDIATE_REPLY_SEQUENCE_SAMPLE flag in DDS_WriteParams_t::flag within connext::WriteSample::info().

A connext::Requester can detect if a reply is the last reply of a sequence of replies by checking that the flag DDS_INTERMEDIATE_REPLY_SEQUENCE_SAMPLE is not set in DDS_SampleInfo::flag within connext::Sample::info().

See also: send_reply(const URep&, const SampleIdentity_t&); connext::WriteSample

◆ send_reply() [3/3]

template<typename TReq , typename TRep >

template<typename URep >

void connext::Replier< TReq, TRep >::send_reply	(	WriteSampleRef< URep > &	reply,
		const SampleIdentity_t &	related_request_id
	)

Sends a reply for a previous request using a SampleRef.

See also: connext::WriteSampleRef; connext::Requester::send_request(WriteSampleRef<UReq>&); connext::Replier::send_reply(WriteSample<URep>&, const SampleIdentity_t&); Basic Requester example using SampleRef

◆ receive_request() [1/2]

template<typename TReq , typename TRep >

bool connext::Replier< TReq, TRep >::receive_request	(	connext::Sample< TReq > &	request,
		const DDS_Duration_t &	max_wait
	)

Waits for a request and copies its contents into a Sample.

Equivalent to using wait_for_requests(int, const Duration_t&) and take_request(Sample<TReq>&)

See also: connext::Sample; wait_for_requests(int, const Duration_t&); take_request(Sample<TReq>&); Basic Replier example

◆ receive_request() [2/2]

template<typename TReq , typename TRep >

bool connext::Replier< TReq, TRep >::receive_request	(	connext::SampleRef< TReq >	request,
		const DDS_Duration_t &	max_wait
	)

Waits for a request and copies its contents into a SampleRef.

See also: connext::Requester::receive_reply(SampleRef<TRep>, const Duration_t&)

◆ receive_requests() [1/2]

template<typename TReq , typename TRep >

Replier< TReq, TRep >::LoanedSamplesType connext::Replier< TReq, TRep >::receive_requests ( const DDS_Duration_t & max_wait )

Waits for multiple requests and provides a loaned container to access them.

Equivalent to using receive_requests(int, int, const Duration_t&) with min_count=1 and max_count=DDS_LENGTH_UNLIMITED

See also: connext::LoanedSamples; receive_requests(int, int, const Duration_t&)

◆ receive_requests() [2/2]

template<typename TReq , typename TRep >

Replier< TReq, TRep >::LoanedSamplesType connext::Replier< TReq, TRep >::receive_requests	(	int	min_request_count,
		int	max_request_count,
		const DDS_Duration_t &	max_wait
	)

Waits for multiple requests and provides a loaned container to access them.

Equivalent to using wait_for_requests(int, const Duration_t&) and take_requests(int)

See also: connext::LoanedSamples; wait_for_requests(int, const Duration_t&); take_requests(int)

◆ wait_for_requests() [1/2]

template<typename TReq , typename TRep >

bool connext::Replier< TReq, TRep >::wait_for_requests ( const DDS_Duration_t & max_wait )

Waits for requests.

Equivalent to wait_for_requests(int, const Duration_t&) with min_count=1

See also: wait_for_requests(int, const Duration_t&)

◆ wait_for_requests() [2/2]

template<typename TReq , typename TRep >

bool connext::Replier< TReq, TRep >::wait_for_requests	(	int	min_count,
		const DDS_Duration_t &	max_wait
	)

Waits for requests.

This operation waits for min_count requests to be available. It will wait up to max_wait .

This operation is similar to connext::Requester::wait_for_replies(int, const Duration_t&).

Parameters

min_count	Minimum number of requests that need to be available for this operation to unblock.
max_wait	Maximum waiting time after which this operation unblocks regardless of how many requests are available.

Returns: true if at least min_count requests were available before max_wait elapsed, or false otherwise.

See also: take_requests(int); connext::Requester::wait_for_replies(int, const Duration_t&)

◆ take_request() [1/2]

template<typename TReq , typename TRep >

bool connext::Replier< TReq, TRep >::take_request ( connext::Sample< TReq > & request )

Copies the contents of a request into a Sample.

See also: connext::Requester::take_reply(Sample<TRep>&)

◆ take_request() [2/2]

template<typename TReq , typename TRep >

bool connext::Replier< TReq, TRep >::take_request ( connext::SampleRef< TReq > request )

Copies the contents of a request into a SampleRef.

See also: connext::Requester::take_reply(SampleRef<TRep>)

◆ take_requests()

template<typename TReq , typename TRep >

Replier< TReq, TRep >::LoanedSamplesType connext::Replier< TReq, TRep >::take_requests ( int max_samples = DDS_LENGTH_UNLIMITED )

Provides a loaned container to access the existing requests.

See also: connext::Requester::take_replies(int)

◆ read_request() [1/2]

template<typename TReq , typename TRep >

bool connext::Replier< TReq, TRep >::read_request ( connext::Sample< TReq > & request )

Copies the contents of a request into a Sample.

This operation is equivalent to connext::Replier::take_request(Sample<TReq>&) except the request remains in the Replier and can be read or taken again.

◆ read_request() [2/2]

template<typename TReq , typename TRep >

bool connext::Replier< TReq, TRep >::read_request ( connext::SampleRef< TReq > request )

Copies the contents of a request into a SampleRef.

See also: connext::Requester::read_reply(SampleRef<TRep>)

◆ read_requests()

template<typename TReq , typename TRep >

Replier< TReq, TRep >::LoanedSamplesType connext::Replier< TReq, TRep >::read_requests ( int max_samples = DDS_LENGTH_UNLIMITED )

Provides a loaned container to access the existing requests.

This operation is equivalent to connext::Replier::take_requests(int) except the requests remain in the Replier and can be read or taken again.

◆ get_request_datareader()

template<typename TReq , typename TRep >

Replier< TReq, TRep >::RequestDataReader * connext::Replier< TReq, TRep >::get_request_datareader

inline

Retrieves the underlying DDSDataReader.

See also: connext::Requester::get_reply_datareader()

◆ get_reply_datawriter()

template<typename TReq , typename TRep >

Replier< TReq, TRep >::ReplyDataWriter * connext::Replier< TReq, TRep >::get_reply_datawriter

inline

Retrieves the underlying DDSDataWriter.

See also: connext::Requester::get_request_datawriter()

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ Request

◆ Reply

◆ ReplyDataWriter

◆ RequestDataReader

Constructor & Destructor Documentation

◆ Replier() [1/2]

◆ Replier() [2/2]

◆ ~Replier()

Member Function Documentation

◆ send_reply() [1/3]

◆ send_reply() [2/3]

◆ send_reply() [3/3]

◆ receive_request() [1/2]

◆ receive_request() [2/2]

◆ receive_requests() [1/2]

◆ receive_requests() [2/2]

◆ wait_for_requests() [1/2]

◆ wait_for_requests() [2/2]

◆ take_request() [1/2]

◆ take_request() [2/2]

◆ take_requests()

◆ read_request() [1/2]

◆ read_request() [2/2]

◆ read_requests()

◆ get_request_datareader()

◆ get_reply_datawriter()