操作系统管理硬件

操作系统管理硬件"/>

操作系统管理硬件

操作系统有两个基本功能：

1）防止硬件被失控的应用程序滥用。

2）像应用程序提供一些简单的机制来控制复杂而又通常大相径庭的低级硬件设备。操作系统通过几个抽象概念实现上述功能：进程，虚拟内存和文件

进程

对于指令和数据的抽象

线程

一系列可以与其他同类并行执行的指令，a thread of execution is the smallest sequence of programmed instructions. Multiple threads can exist within one process, executing concurrently and sharing resources such as memory, while different processes do not share these resources.

• 两者不同：

  • processes are typically independent, while threads exist as subsets of a process
  • processes carry considerably more state information than threads, whereas multiple threads within a process share process state as well as memory and other resources
  • processes have separate address spaces, whereas threads share their address spac