1. A method of using an event manager to effect a library function call from a caller service processor application to a function in a library of data processing functions that carry out particular tasks of data processing, the library compiled into a callee service processor application, the caller service processor application, the callee service processor application, and the event manager comprising modules of computer program instructions that execute on a service processor of a computer, the library exposing within the callee service processor application an application programming interface (‘API’) of direct calls to computer software functions of the library, the direct calls having characteristic signatures, the signatures including call parameters, the caller service processor application comprising an API for one or more event handling functions having signatures of corresponding direct calls to data processing functions in the library's API, the caller service processor application's API calls directed to event handling functions that effect event handling only, the method comprising: passing, by the caller service processor application to the event manager through the caller service processor application's API, an event representing the library function call; passing, by the event manager to the callee service processor application, the event representing the library function call; executing by the callee service processor application the library function call, including retrieving return data from the library function call; returning, by the callee service processor application to the event manager, an event representing the return data from the library function call; and returning, by the event manager to the caller service processor application, the event representing the return data from the library function call.