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👤 Author: by 958794067qqcom 2019-09-16 06:32:08 |
Process life circle
When a process executes ,it will changes state. The state of a process is defined in part by the current activity of that process. And their names are vary from different systems.
NEW : When the process is being started or created.
Ready: The process is waiting to be assigned to a process.
Running : when it comes to this state. Instructions are being executed.
Waiting : The process is waiting for some event to occur , such as waiting users to input by keyboard , or waiting a signal.
Terminated: Once the process has finished execution , the operating system terminate the process.
Why process need PCB
The process control block records all the information that the operating system needs to describe the current state of the process and control the process's operation. The operating system controls and manages concurrent lying processes based on the PCB