Accessing HPI Domains | Using |
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The following figure illustrates an example configuration with four domains and three shelves.
Figure 4-1 Multishelf Library - Representation of Shelves as Domains
Any FRUs available in a shelf are represented as HPI resources together with Resource Data Records (RDRs) corresponding to that FRU. Whenever a FRU is added to or removed from a shelf, the corresponding HPI resource/RDR is added/removed from the HPI domain.
4.3.2Accessing HPI Domains
In order to access an HPI domain, you must open a session via the HPI call saHpiSessionOpen() and provide as first parameter the domain ID of the corresponding HPI domain. How to obtain the domain ID is described later within this section about the multishelf HPI library.
If you want to access several shelves, then you need to open several sessions simultaneously, one session for each HPI domain which represents a shelf. It is also possible to open several sessions for one HPI domain/shelf only as well.
When the connection to a shelf is lost, all running HPI calls which access the corresponding domain return immediately with the error code SA_HPI_ERR_NO_RESPONSE. All open sessions for the affected domain are automatically closed by the multishelf library. In the meantime, the library tries to regain access to the shelf. As soon as the connection is reestablished, the domain is recreated and the application can open another session and access the domain again. Whenever a domain is created or removed, an HPI event from the HPI Communication State sensor is generated in the default domain (see Connection State Sensor on page 30 and HPI Domain Events on page 31).
HPI events are handled domain wide. This means that HPI events from a shelf or FRUs in that shelf are only visible and can only be received within the session that corresponds to that domain.
System Management Interface Based on | 25 |