CHAPTER 5 Concurrency: Mutual Exclusion and Synchronization (并发性：互斥和同步)
Concurrency (并发性) Communication among processes Sharing of and competing(竞争)or resources Synchronization of the activities of multiple processes Allocation of processor time to processer
Concurrency Multiple applications Multiprogramming Structured application Application can be a set of concurrent processes Operating-system structure Operating system is a set of processes or th reads
5.1 PRINCIPLES OF NCURRENCY (并发的原理) Difficulties with Concurrency 1. Sharing global resources 2. Management of allocation of resources 3. It become very difficult to locate a Programming errors
A Simple example procedure echo; Var out in: character; begin input (in, keyboard) out: s in outputout, display)i end