#第三章-进程 Processes
Process--A program in execution. It's the unit of work in a modern time-sharing system.
Process includes these things, process stack, data section, heap, text.
◎ Process in Memory
A program by itself is not a process. A program is a passive entity. A process is an active entity.
A program becomes a process when an executable file is loaded into memory.
Although two processes may be associated with the same program , they are nevertheless considered two separate execution sequences.
#Process State
一个进程可能拥有的状态：
- New，进程正被创建
- Running，指令正被执行
- Waiting，进程正在等待某些事情发生
- Ready，进程正等待被赋给处理器
- Terminated，进程已完成执行
Only one process can be running on any processor at any instant.