RtpsReliableReaderProtocol_t Class Reference

Qos related to reliable reader protocol defined in RTPS. More...

Inherits Struct.

Public Member Functions
	RtpsReliableReaderProtocol_t ()
	Constructor with default values.
	RtpsReliableReaderProtocol_t (Duration_t min_heartbeat_response_delay, Duration_t max_heartbeat_response_delay, Duration_t heartbeat_suppression_duration, Duration_t nack_period, Duration_t round_trip_time, Duration_t app_ack_period, Duration_t min_app_ack_response_keep_duration)
	Constructor with given durations.
Public Member Functions inherited from Struct
abstract boolean	equals (Object obj)
abstract int	hashCode ()
String	toString ()

Public Attributes
final Duration_t	min_heartbeat_response_delay
	The minimum delay to respond to a heartbeat.
final Duration_t	max_heartbeat_response_delay
	The maximum delay to respond to a heartbeat.
final Duration_t	heartbeat_suppression_duration
	The duration a reader ignores consecutively received heartbeats.
final Duration_t	nack_period
	The period at which to send NACKs.
int	receive_window_size = 256
	The number of received out-of-order samples a reader can keep at a time.
final Duration_t	round_trip_time
	The duration from sending a NACK to receiving a repair of a sample.
final Duration_t	app_ack_period
	The period at which application-level acknowledgment messages are sent.
int	samples_per_app_ack
	The minimum number of samples acknowledged by one application-level acknowledgment message.

Additional Inherited Members
Protected Member Functions inherited from Struct
	Struct ()
abstract void	pull_from_nativeI (long native_status)
abstract void	push_to_nativeI (long native_status)

Detailed Description

Qos related to reliable reader protocol defined in RTPS.

It is used to config reliable reader according to RTPS protocol.

Properties:

RxO = N/A
Changeable = NO

QoS:

com.rti.dds.infrastructure.DataReaderProtocolQosPolicy com.rti.dds.infrastructure.DiscoveryConfigQosPolicy

Constructor & Destructor Documentation

RtpsReliableReaderProtocol_t

(

)

Constructor with default values.

RtpsReliableReaderProtocol_t	(	Duration_t	min_heartbeat_response_delay,
		Duration_t	max_heartbeat_response_delay,
		Duration_t	heartbeat_suppression_duration,
		Duration_t	nack_period,
		Duration_t	round_trip_time,
		Duration_t	app_ack_period,
		Duration_t	min_app_ack_response_keep_duration
	)

Constructor with given durations.

Member Data Documentation

final Duration_t min_heartbeat_response_delay

The minimum delay to respond to a heartbeat.

When a reliable reader receives a heartbeat from a remote writer and finds out that it needs to send back an ACK/NACK message, the reader can choose to delay a while. This sets the value of the minimum delay.

[default] 0 seconds

[range] [0, 1 year], <= max_heartbeat_response_delay

final Duration_t max_heartbeat_response_delay

The maximum delay to respond to a heartbeat.

When a reliable reader receives a heartbeat from a remote writer and finds out that it needs to send back an ACK/NACK message, the reader can choose to delay a while. This sets the value of maximum delay.

[default] The default value depends on the container policy:

For com.rti.dds.infrastructure.DiscoveryConfigQosPolicy : 0 seconds
For com.rti.dds.infrastructure.DataReaderProtocolQosPolicy : 0.5 seconds

[range] [0, 1 year], >= min_heartbeat_response_delay

final Duration_t heartbeat_suppression_duration

The duration a reader ignores consecutively received heartbeats.

When a reliable reader receives consecutive heartbeats within a short duration that will trigger redundant NACKs, the reader may ignore the latter heartbeat(s). This sets the duration during which additionally received heartbeats are suppressed.

[default] 0.0625 seconds

[range] [0, 1 year],

final Duration_t nack_period

The period at which to send NACKs.

A reliable reader will send periodic NACKs at this rate when it first matches with a reliable writer. The reader will stop sending NACKs when it has received all available historical data from the writer.

[default] 5 seconds

[range] [1 nanosec, 1 year]

int receive_window_size = 256

The number of received out-of-order samples a reader can keep at a time.

A reliable reader stores the out-of-order samples it receives until it can present them to the application in-order. The receive window is the maximum number of out-of-order samples that a reliable reader keeps at a given time. When the receive window is full, subsequently received out-of-order samples are dropped.

[default] 256

[range] [>= 1]

final Duration_t round_trip_time

The duration from sending a NACK to receiving a repair of a sample.

This round-trip time is an estimate of the time starting from when the reader sends a NACK for a specific sample to when it receives that sample. For each sample, the reader will not send a subsequent NACK for it until the round-trip time has passed, thus preventing inefficient redundant requests.

[default] 0 seconds

[range] [0 nanosec, 1 year]

final Duration_t app_ack_period

The period at which application-level acknowledgment messages are sent.

A com.rti.dds.subscription.DataReader sends application-level acknowledgment messages to a com.rti.dds.publication.DataWriter at this periodic rate, and will continue sending until it receives a message from the com.rti.dds.publication.DataWriter that it has received and processed the acknowledgment and an AppAckConfirmation has been received by the com.rti.dds.subscription.DataReader. Note: application-level acknowledgment messages can also be sent non-periodically, as determined by com.rti.dds.infrastructure.RtpsReliableReaderProtocol_t.samples_per_app_ack.

[default] 5 seconds

[range] [1 nanosec, 1 year]

int samples_per_app_ack

The minimum number of samples acknowledged by one application-level acknowledgment message.

This setting applies only when com.rti.dds.infrastructure.ReliabilityQosPolicy.acknowledgment_kind = com.rti.dds.infrastructure.ReliabilityQosPolicyAcknowledgmentModeKind.ReliabilityQosPolicyAcknowledgmentModeKind.APPLICATION_EXPLICIT_ACKNOWLEDGMENT_MODE or com.rti.dds.infrastructure.ReliabilityQosPolicyAcknowledgmentModeKind.ReliabilityQosPolicyAcknowledgmentModeKind.APPLICATION_AUTO_ACKNOWLEDGMENT_MODE

A com.rti.dds.subscription.DataReader will immediately send an application-level acknowledgment message when it has at least this many samples that have been acknowledged. It will not send an acknowledgment message until it has at least this many samples pending acknowledgment.

For example, calling com.rti.dds.subscription.DataReader.acknowledge_sample this many times consecutively will trigger the sending of an acknowledgment message. Calling com.rti.dds.subscription.DataReader.acknowledge_all may trigger the sending of an acknowledgment message, if at least this many samples are being acknowledged at once.

This is independent of the com.rti.dds.infrastructure.RtpsReliableReaderProtocol_t.app_ack_period, where a com.rti.dds.subscription.DataReader will send acknowledgement messages at the periodic rate regardless.

When this is set to com.rti.dds.infrastructure.ResourceLimitsQosPolicy.LENGTH_UNLIMITED, then acknowledgement messages are sent only periodically, at the rate set by com.rti.dds.infrastructure.RtpsReliableReaderProtocol_t.app_ack_period.

[default] 1

[range] [1, 1000000], or com.rti.dds.infrastructure.ResourceLimitsQosPolicy.LENGTH_UNLIMITED