Development Phases of a TxCore Application
Development Phases of a TxCore Application First, develop new classes with characteristics like persistence, recoverability, and concurrency control. Then develop the applications that make use of the new classes of objects. Although these two phases may be performed in parallel and by a single person, this guide refers to the first step as the job of the class developer, and the second as the job of the applications developer. The class developer defines appropriate save_state and restore_state operations for the class, sets appropriate locks in operations, and invokes the appropriate TxCore class constructors. The applications developer defines the general structure of the application, particularly with regard to the use of atomic actions. This chapter outlines a simple application, a simple FIFO Queue class for integer values. The Queue is implemented with a doubly linked list structure, and is implemented as a single object. This example is used throughout the rest of this manual to illustrate the various mechanisms provided by TxCore. Although this is an unrealistic example application, it illustrates all of the TxCore modifications without requiring in depth knowledge of the application code. Note The application is assumed not to be distributed. To allow for distribution, context information must be propagated either implicitly or explicitly.