Day 01Part 14 – Operating system for computer – Concept of process Control Block in very easy way
Day 01Part 14 – Operating system for computer – Concept of process Control Block in very easy way
Contents [hide]
- 1 Process Control Block (PCB) – Explained in an Easy Way
- 2 What is a Process Control Block (PCB)?
- 3 Information Stored in PCB
- 4 How PCB Works?
- 5 Process States and PCB
- 6 Why is PCB Important?
- 7 Simple Example to Understand PCB
- 8 Day 01Part 14 – Operating system for computer – Concept of process Control Block in very easy way
- 9 Medical gases Health Technical Memorandum 02-01
- 10 Chapter 3 Process Description and Control
- 11 Operating System
Process Control Block (PCB) – Explained in an Easy Way
When you run any program on a computer, the operating system (OS) manages it as a process. To track and manage each process efficiently, the OS maintains a Process Control Block (PCB).
What is a Process Control Block (PCB)?
PCB is a data structure used by the Operating System to store information about a process. It keeps all details needed for process execution and management.
Think of PCB like an Identity Card for a process, which contains all important details about it.
Information Stored in PCB
A PCB contains the following essential details:
| Component | Description |
|---|---|
| Process ID (PID) | Unique identification number for each process. |
| Process State | The current state of the process (New, Ready, Running, Waiting, Terminated). |
| Program Counter (PC) | The memory address of the next instruction to be executed. |
| CPU Registers | Stores CPU-related data (like accumulator, index registers, etc.). |
| Memory Management Info | Details about memory allocation (base and limit registers, page tables). |
| I/O Information | List of input/output devices assigned to the process. |
| Scheduling Information | Priority, scheduling queue details. |
| Accounting Information | CPU time used, process creation time, etc. |
How PCB Works?
When a process starts, the OS creates a PCB for it.
When the process runs, the CPU uses PCB data for execution.
If the process is paused or waiting, its PCB keeps track of its state.
When the process finishes, the OS deletes its PCB.
Process States and PCB
A process moves through different states, and the PCB updates its Process State accordingly.
New → Process is being created.
Ready → Waiting to get CPU time.
Running → Executing instructions.
Waiting → Waiting for input/output operation.
Terminated → Process has finished execution.
Why is PCB Important?
Helps the OS manage multiple processes efficiently.
Saves the state of a process during context switching.
Stores critical information for process scheduling.
Simple Example to Understand PCB
Imagine a to-do list where each task has:
- Task ID (Process ID)
- Status (Pending, In Progress, Completed)
- Assigned Person (CPU registers)
- Deadline (Scheduling info)
Similarly, the OS maintains PCBs to keep track of all processes running on the system!
Would you like a diagram for better understanding?