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ResourceLimitsQosPolicy Class

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

Namespace:  OpenDDSharp.DDS
Assembly:  OpenDDSharp (in OpenDDSharp.dll) Version:
public class ResourceLimitsQosPolicy

The ResourceLimitsQosPolicy type exposes the following members.

Public propertyMaxInstances
Gets or sets the maximum number of instances that a DataWriter or DataReader can manage. The default value is LengthUnlimited
Public propertyMaxSamples
Gets or sets the maximum number of samples a single DataWriter or DataReader can manage across all of its instances. The default value is LengthUnlimited
Public propertyMaxSamplesPerInstance
Gets or sets the maximum number of samples that can be managed for an individual instance in a single DataWriter or DataReader. The default value is LengthUnlimited
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
Public fieldStatic memberLengthUnlimited
Used to indicate the absence of a particular limit.

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 behavior in this case depends on the setting for the Reliability QoS. If reliability is BestEffort then DDS is allowed to drop samples. If the reliability is Reliable, DDS will block the DataWriter or discard the sample at the DataReader in order not to lose existing samples.

The setting of ResourceLimits MaxSamples must be consistent with the MaxSamplesPerInstance. For these two values to be consistent they must verify that “MaxSamples >= MaxSamplesPerInstance.”

The setting of ResourceLimits MaxSamplesPerInstance must be consistent with the History Depth. For these two QoS to be consistent, they must verify that "depth <= MaxSamplesPerInstance".

An attempt to set this policy to inconsistent values when an entity is created of via a SetQos operation will cause the operation to fail.

See Also