Process Life Cycle

 Process Life Cycle:

The process life cycle can be divided into several stages as a state each with certain characteristics that describes each process. It means that as a process start executing it goes through one state to another state. Each process may be in one of the following stages.

1)      New 2) Ready 3) Running 4) Waiting 5) Terminate



 

1)      New:  The process has been created in this state. The operating system is aware of the existence of this task, but the task has not been allocated a priority and a context and has not been included into the list of schedulable tasks.

2)      Ready: There may be several tasks in ready state. The attributes of the task and the resources required to run it must be available for it to be placed in the 'ready' state.

3)      Running: This is the task which has control of the CPU. It will normally be the task which has the highest current priority of the tasks which are ready to run.

4)      Waiting: The execution of tasks placed in this state has been suspended because the task requires some resources which is not available or because the task is waiting for some signal from the plant, e.g., input from the analog-to-digital converter, or the task is waiting for the elapse of time.

5)      Terminate: When the process finally stops, a process terminates when it finishes executing its last statement. The operating system has not as yet been made aware of the existence of this task, although it may be resident in the memory of the computer

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