2010年自考工学类“操作系统原理”复习资料(国外英语资料).doc

2010年自考工学类“操作系统原理”复习资料(国外英语资料) This chapter examines the knowledge points: 1, process sequence and concurrency, 2, time related errors 3, the relevant critical area 4, the process of mutual exclusion 5, the process of synchronization 6, process communication 7, thread concept Self taught in this chapter: understanding the process is the basic unit of execution in an operating system, and there are often many processes in multiprogramming systems that take turns to take care of the processor. These cross executed concurrent processes may or may not be related to each other. When concurrent process competes for shared resources, there will be errors related to time. Therefore, process synchronization and mutual exclusion should be adopted to make rational use of shared resources to ensure system security. When collaboration between processes has to be carried out through information exchange, process communication can be used to achieve the goal. The key point is to analyze the error related to time; to realize synchronization and mutual exclusion of processes with PV operation; to realize process communication with mailbox. First, the order of process and concurrency (understanding) Some people say that in the program is not a jump statement and repeat statement, how is the order of execution? Note that this refers to the process in the processor execution, because each processor can perform an operation, so each instruction must perform in order to enter the CPU, if there is an instruction is to jump, then the implementation of this directive after the jump instruction will take out the destination address into the CPU operation, the order is specified. So for CPU, the process is always in order. A process is an execution of a program on a data set, and the results of the same program and the same data set must be the same. This is reproducibility. Simultaneous execution is not really simultaneous, because at any point in the CPU there is only one process running.