Resource_Limits QOS Policy

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Resource_Limits QOS Policy


It is stated in the manual (5.2.3) that "If a keyed data type is not used, there is only a single instance of the Topic, so max_samples_per_instance must equal max_samples.".

What I’m actually seeing when testing this is that the only restriction is max_samples_per_instance must be <= max_samples. (This originated from the following statement in the manual: "DDS must be able to store max_samples_per_instance for at least one instance”).

Meaning I can also set Max_samples to be greater than max_samples_per_instance.

Is it a documentation mistake? Is the above restrictions are correct?


Thank you,

sara's picture
Last seen: 3 weeks 5 days ago
Joined: 01/16/2013
Posts: 125

Hi Gal,

According to the max_samples_per_instance API documentation (full information here):

While an unkeyed type is logically considered as a single instance, for unkeyed types this value has to be equal to max_samples or DDS_LENGTH_UNLIMITED.

That is why, setting max_samples_per_instance has no actual effect for unkeyed types. The only limit is max_samples that is the physical limit of the queue.