The Breakpoint Executive module is primarily a request handler. It maintains information about program state, such as current breakpoint location in source code and the list of currently instantiated parallel data objects. For meta-information such as type descriptions of the parallel data structures or lists of all user-defined functions that can be called, the Breakpoint Executive module must consult the Type module. To serve requests for parallel data, the Breakpoint Executive calls access functions in the executing program. These access functions reside in the (modified) user program in order to have access to the program variables and functions.