Go Systems Programming

The various states of a Unix process

Strictly speaking, a process is an execution environment that contains instructions, user-data and system-data parts, and other kinds of resources that are obtained during runtime. A program is a file that contains instructions and data, which are used for initializing the instruction and user-data parts of a process.

Back when the Unix operating system was first introduced, computers had single CPUs without multiple cores and a small amount of RAM. However, Unix was a multiuser and multitasking operating system. In order to actually be a multiuser and do multitasking, it had to be able to run each individual process sporadically, which means that a process should have multiple states. The following figure ...