提供导致进程状态变化的调用接口，包括创建、删除、调度、阻塞、时间到、挂起、激

活等；实现进程列表显示的接口；这里设计的进程是一个假设的对象实体，是由程序自己创

建和删除，不是系统维护的进程。-Availability leads to the call interface of the process status changes, including create, delete, scheduling, blocking, time to suspend, activate, etc.　the list of processes to display interface　process designed here is a hypothetical object entity is created by the program itself.and delete, not the system maintenance process.