Abstract Concurrent Behavior in Object-Oriented Programming Models Abstract Object-oriented(OO)technique has been widely used in the design and construction of software systems.Object-oriented models describe the real world activities in a natural way.The objects in the models are the direct simulations of the entities in the real or mind world.Developing software with OO technique can minimize the semantic gap between problems and solutions.It makes software development processes more natural and,thus, promotes software productivity. The real-world activities are usually carried out concurrently.Currently,OO models only support the specification of the sequential behaviors of a system.To model the concurrent behaviors of the real-world activities,concurrency must be introduced into OO models. The main concern of this dissertation is to study how to introduce concurrency into OO models.The introduced concurrent mechanism should be compatible with OO models and does not hamper the existing properties of OO models. In this dissertation,all kinds of problems encountered in introducing concurrency into OO models are analyzed first.Then,based on the study of some existing concurrent object-oriented models,the dissertation present a concurrent object-oriented model around concurrent objects.In the model,concurrency is introduced in an integrated way. Objects may have private threads.Threads in objects execute concurrently.The remote procedure calls are used as communication mechanism between objects.Objects control their own message accepting and the concurrent executions of their private threads.The specification of concurrency control in a class can be inherited by its subclasses.The formal semantics of the concurrent objects in the presented model has been given in CSP.At last, C++has been extended based on the presented concurrent object-oriented model. Keywords:Object-Oriented,Programming,Concurrent Objects,CSP,C++ iiAbstract ii Concurrent Behavior in Object-Oriented Programming Models Abstract Object-oriented(OO) technique has been widely used in the design and construction of software systems. Object-oriented models describe the real world activities in a natural way. The objects in the models are the direct simulations of the entities in the real or mind world. Developing software with OO technique can minimize the semantic gap between problems and solutions. It makes software development processes more natural and, thus, promotes software productivity. The real-world activities are usually carried out concurrently. Currently, OO models only support the specification of the sequential behaviors of a system. To model the concurrent behaviors of the real-world activities, concurrency must be introduced into OO models. The main concern of this dissertation is to study how to introduce concurrency into OO models. The introduced concurrent mechanism should be compatible with OO models and does not hamper the existing properties of OO models. In this dissertation, all kinds of problems encountered in introducing concurrency into OO models are analyzed first. Then, based on the study of some existing concurrent object-oriented models, the dissertation present a concurrent object-oriented model around concurrent objects. In the model, concurrency is introduced in an integrated way. Objects may have private threads. Threads in objects execute concurrently. The remote procedure calls are used as communication mechanism between objects. Objects control their own message accepting and the concurrent executions of their private threads. The specification of concurrency control in a class can be inherited by its subclasses. The formal semantics of the concurrent objects in the presented model has been given in CSP. At last, C++ has been extended based on the presented concurrent object-oriented model. Keywords: Object-Oriented, Programming, Concurrent Objects, CSP, C++