ddsf:public:guidebook:06_append:02_quality_of_service:ownership
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ddsf:public:guidebook:06_append:02_quality_of_service:ownership [2021/07/14 15:54] murphy ↷ Links adapted because of a move operation |
ddsf:public:guidebook:06_append:02_quality_of_service:ownership [2021/07/14 15:55] (current) murphy ↷ Links adapted because of a move operation |
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| ===== SHARED ''kind'' ===== | ===== SHARED ''kind'' ===== | ||
| - | This setting indicates that the Service does not enforce unique ownership for each [[ddsf:public:guidebook:06_append:glossary:i:instance|instance]]. In this case, multiple writers can update the same data-object instance. The [[ddsf:private:guidebook:06_append:glossary:s:subscriber|subscriber]] to the ''[[ddsf:private:guidebook:06_append:glossary:t:topic|Topic]]'' will be able to access modifications from all ''DataWriter'' objects, subject to the settings of other [[ddsf:public:guidebook:06_append:glossary:q:quality_of_service_qos_policies|QoS]] that may filter particular samples (e.g., the TIME_BASED_FILTER or [[ddsf:public:guidebook:06_append:glossary:h:history_qos|HISTORY QoS]] policy). In any case there is no “filtering” of modifications made based on the identity of the ''DataWriter'' that causes the modification. | + | This setting indicates that the Service does not enforce unique ownership for each [[ddsf:public:guidebook:06_append:glossary:i:instance|instance]]. In this case, multiple writers can update the same data-object instance. The [[ddsf:public:guidebook:06_append:glossary:s:subscriber|subscriber]] to the ''[[ddsf:public:guidebook:06_append:glossary:t:topic|Topic]]'' will be able to access modifications from all ''DataWriter'' objects, subject to the settings of other [[ddsf:public:guidebook:06_append:glossary:q:quality_of_service_qos_policies|QoS]] that may filter particular samples (e.g., the TIME_BASED_FILTER or [[ddsf:public:guidebook:06_append:glossary:h:history_qos|HISTORY QoS]] policy). In any case there is no “filtering” of modifications made based on the identity of the ''DataWriter'' that causes the modification. |
| ===== EXCLUSIVE ''kind'' ===== | ===== EXCLUSIVE ''kind'' ===== | ||
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| The behavior of the system is as if the determination was made independently by each ''DataReader''. Each ''DataReader'' may | The behavior of the system is as if the determination was made independently by each ''DataReader''. Each ''DataReader'' may | ||
| - | detect the change of ownership at a different time. It is not a [[ddsf:private:guidebook:06_append:glossary:r:requirement|requirement]] that at a particular point in time all the ''DataReader'' objects for that ''Topic'' have a consistent picture of who owns each instance. | + | detect the change of ownership at a different time. It is not a [[ddsf:public:guidebook:06_append:glossary:r:requirement|requirement]] that at a particular point in time all the ''DataReader'' objects for that ''Topic'' have a consistent picture of who owns each instance. |
| It is also not a requirement that the ''DataWriter'' objects are aware of whether they own a particular instance. There is no error or notification given to a ''DataWriter'' that modifies an instance it does not currently own. | It is also not a requirement that the ''DataWriter'' objects are aware of whether they own a particular instance. There is no error or notification given to a ''DataWriter'' that modifies an instance it does not currently own. | ||
ddsf/public/guidebook/06_append/02_quality_of_service/ownership.1626292441.txt.gz · Last modified: 2021/07/14 15:54 by murphy
