When an application calls a WOSA/XFS API function one of the following processing scenarios takes place. Note that this classification is distinct from the API synchronization modes discussed above. See Section 5 for the mapping of API functions to SPI functions.
· The function is converted by the XFS Manager directly into the corresponding SPI function (e.g., WFSAsyncRegister).
· The XFS Manager performs some preprocessing and then converts the function into the corresponding SPI function (e.g., WFSAsyncExecute).
· The XFS Manager performs some preprocessing and then translates the API function to a different SPI function, which it passes to the service provider. Most of the synchronous API functions (e.g., WFSLock) are of this type, since they are translated to their asynchronous SPI equivalents.
· The XFS Manager performs some preprocessing and then translates the API function to multiple SPI functions, which it passes to the service provider (e.g., WFSOpen).
· The function is completely processed inside the XFS Manager (e.g., WFSIsBlocking, WFSSetBlockingHook).
Service providers (and sometimes applications) call the XFS Manager for the support functions defined in Section 6 and for the configuration functions defined in Section 7.