DDS_RtpsReliableWriterProtocol_t Struct Reference

<<cert>> QoS related to the reliable writer protocol defined in RTPS. More...

#include <dds_c_infrastructure.h>

Data Fields
struct DDS_Duration_t	heartbeat_period
	The period at which to send heartbeats.
DDS_Long	heartbeats_per_max_samples
	The number of heartbeats per send queue.
DDS_Long	max_send_window
	The maximum size of a reliable send window.
DDS_Long	max_heartbeat_retries
	The maximum number of heartbeat retries before marking a remote reader as inactive.

---

Detailed Description

<<cert>> QoS related to the reliable writer protocol defined in RTPS.

It is used to configure a reliable writer according to RTPS protocol.

Properties:

RxO = N/A
Changeable = NO

QoS:

DDS_DataWriterProtocolQosPolicy

---

Field Documentation

struct DDS_Duration_t DDS_RtpsReliableWriterProtocol_t::heartbeat_period

The period at which to send heartbeats.

A reliable writer will send periodic heartbeat at this rate.

[default] 3.0 seconds

[range] [1 nanosec,1 year]

DDS_Long DDS_RtpsReliableWriterProtocol_t::heartbeats_per_max_samples

The number of heartbeats per send queue.

A piggyback heartbeat will be sent every [DDS_ResourceLimitsQosPolicy::max_samples/heartbeats_per_max_samples] number of samples.

If set to zero, no piggyback heartbeat will be sent. If DDS_ResourceLimitsQosPolicy::max_samples is DDS_LENGTH_UNLIMITED, 100 million is assumed as the maximum value in the calculation.

[default] 1

[range] [0, 100 million]

• For DDS_DataWriterProtocolQosPolicy::rtps_reliable_writer:
  heartbeats_per_max_samples<= DDS_ResourceLimitsQosPolicy::max_samples

DDS_Long DDS_RtpsReliableWriterProtocol_t::max_send_window

The maximum size of a reliable send window.

A reliable DataWriter may maintain a send window of samples in-flight that have not been acknowledged by its DataReaders. The max_send_window is the maximum number of unacknowledged samples in-flight. When the window is at max_send_window, subsequent writes will pass but not publish any data over the network.

[default] DDS_LENGTH_UNLIMITED, meaning the window will be as large as resource limits allow

[range] [1, 256] of DDS_LENGTH_UNLIMITED

DDS_Long DDS_RtpsReliableWriterProtocol_t::max_heartbeat_retries

The maximum number of heartbeat retries before marking a remote reader as inactive.

When a remote reader has not acked all the samples the reliable writer has in its queue, and max_heartbeat_retries number of periodic heartbeats has been sent without receiving any ack/nack back, the remote reader will be marked as inactive (not alive) and be ignored until it resumes sending ack/nack.

[default] DDS_LENGTH_UNLIMITED

[range] [1, 1 million] or DDS_LENGTH_UNLIMITED