Callable services syntax declarations

Throughout this information, the callable service syntax is shown as a C function prototype; a function declaration for the routine which is called. Data structures are described by C struct definitions.

By using the C function prototype, the argument list as well as the data type of each argument can be shown accurately and in one place. In addition, the prototype makes clear if a parameter is passed by value or by reference. The caller then matches parameters to the argument descriptions.

The application writer's interface is described from the callee's point of view. Usually, when the call is described from the caller's point of view, the data type of each parameter is not clear unless it is explained later in the information. It is also often not clear which parameters are required for calling by reference rather than by value.