信息系统状态过程图_过程状态图中使用的重要术语| 操作系统

信息系统状态过程图

1)上下文切换 (1) Context Switching)

Whenever a process is transferred within the system, it moves within different states. These states are known as the process states. When a process goes from one state to another state inside the system, then it is termed as context switching. It can be said that for executing, a process context switches between the different Process States. Context Switching is very important because, without it, a process cannot be executed.

每当进程在系统内转移时，它就会在不同的状态下移动。这些状态称为过程状态。当进程从系统内部的一种状态转到另一种状态时，则称为上下文切换。可以说，为了执行，过程上下文在不同的过程状态之间切换。上下文切换非常重要，因为没有它，就无法执行进程。

2)开销 (2) Overhead)

As we know that the Running State is the most important state as it is the state in which the process executes inside the processor. So, to maximize the use of the processor and to increase the efficiency and performance of any system, the running state must never be empty. But there are cases when a process residing in the running state completes its execution and goes into the termination state, but due to unavailability of any process in the ready state, the dispatcher is not able to transfer any process into the running state and till that time the running state remains empty. This is known as overhead.

众所周知，运行状态是最重要的状态，因为它是进程在处理器内部执行的状态。因此，为了最大程度地利用处理器并提高任何系统的效率和性能，运行状态一定不能为空。但是在某些情况下，处于运行状态的进程会完成其执行并进入终止状态，但是由于任何处于就绪状态的进程都不可用，因此调度程序无法将任何进程转移到运行状态，直到时间运行状态保持为空。这称为开销。

3)多重编程程度 (3) Degree of Multiprogramming)

It can be defined as the maximum number of processes that can be handled by the main memory at any particular instance of time. The degree of multiprogramming is maintained inside the main memory by the Mid Term Schedulers. This increases the speed and performance of the system.

它可以定义为主存储器在任何特定时间实例可以处理的最大进程数。中期调度程序将多程序的程度保持在主存储器中。这样可以提高系统的速度和性能。

Graphically, the degree of multiprogramming can be represented as follows:

在图形上，多重编程的程度可以表示为：

Here, throughput refers to the number of processes residing in the main memory at that particular instance of time. It is also termed as CPU utilization.

此处，吞吐量是指在该特定时间实例处主内存中驻留的进程数。也称为CPU利用率。

4)调度员 (4) Dispatcher)

The Job of the dispatcher is to dispatch the scheduled processes from the Ready State to the Running State one by one. It should be noted that a process can enter into the running state from no other state but the ready state and this process of transferring the process from the ready state to the running state is performed by the dispatcher.

调度程序的工作是将已调度的进程从就绪状态逐个调度到运行状态。应该注意的是，除了就绪状态外，进程不能从其他状态进入运行状态，并且将进程从就绪状态转移到运行状态的该处理由调度程序执行。