Collaboration diagram for DDS.ResourceLimitsQosPolicy:

Public Attributes
int	MaxInstances

int	MaxSamples

int	MaxSamplesPerInstance

Detailed Description

This QosPolicy will specify the maximum amount of resources, which can be used by a DataWriter or DataReader.

Attributes

Value	Meaning	Concerns	RxO	Changeable
A long: max_samples	Specifies the maximum number of data-samples the DataWriter (or DataReader) can manage across all the instances associated with it. Represents the maximum samples the middleware can store for any one DataWriter (or DataReader). It is inconsistent for this value to be less than max_samples_per_instance. By default, LENGTH_UNLIMITED.	Topic, DataReader, DataWriter	No	No
A long: max_instances	Represents the maximum number of instances DataWriter (or DataReader) can manage. By default, LENGTH_UNLIMITED.
A long: max_samples_per_instance	Represents the maximum number of samples of any one instance a DataWriter (or DataReader) can manage. It is inconsistent for this value to be greater than max_samples. By default, LENGTH_UNLIMITED.

This policy controls the resources that the Service can use in order to meet the requirements imposed by the application and other QoS settings.

If the DataWriter objects are communicating samples faster than they are ultimately taken by the DataReader objects, the middleware will eventually hit against some of the QoS-imposed resource limits. Note that this may occur when just a single DataReader cannot keep up with its corresponding DataWriter. The behaviour in this case depends on the setting for the RELIABILITY QoS. If reliability is BEST_EFFORT, then the Service is allowed to drop samples. If the reliability is RELIABLE, the Service will block the DataWriter or discard the sample at the DataReader in order not to lose existing samples.

The constant LENGTH_UNLIMITED may be used to indicate the absence of a particular limit. For example setting max_samples_per_instance to LENGH_UNLIMITED will cause the middleware to not enforce this particular limit.

The setting of RESOURCE_LIMITS max_samples must be consistent with the max_samples_per_instance. For these two values to be consistent they must verify that “max_samples >= max_samples_per_instance.”

The setting of RESOURCE_LIMITS max_samples_per_instance must be consistent with the HISTORY depth. For these two QoS to be consistent, they must verify that “depth <= max_samples_per_instance.” An attempt to set this policy to inconsistent values when an entity is created via a set_qos operation will cause the operation to fail.

Definition at line 1381 of file DdsDcpsStructs.cs.

Member Data Documentation

◆ MaxInstances

int DDS.ResourceLimitsQosPolicy.MaxInstances

Definition at line 1384 of file DdsDcpsStructs.cs.

◆ MaxSamples

int DDS.ResourceLimitsQosPolicy.MaxSamples

Definition at line 1383 of file DdsDcpsStructs.cs.

◆ MaxSamplesPerInstance

int DDS.ResourceLimitsQosPolicy.MaxSamplesPerInstance

Definition at line 1385 of file DdsDcpsStructs.cs.

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