[This is preliminary documentation and subject to change.]
The LPM API is the programmatic interface by which LPMs communicate and interact with the Admission Control Service (ACS). The LPM API also specifies how LPMs are registered and initialized within the constructs of the ACS.
Such interaction is actually regulated by an abstraction service called the Policy Control Module (PCM). Because it is possible to have multiple LPMs, the PCM filters and aggregates information. For example, the PCM takes information returned from multiple LPMs (if multiple LPMs are installed on the system) and performs logical policy comparisons on their results, then returns one set of information to the ACS.
The LPM API consists of a handful of functions used to allow its interaction with the ACS. The interaction of an LPM with its corresponding policy store is excluded from this interface; such interfacing would be proprietary to the LPM and the policy store.