process-control-block
  • The PCB (Process Control Block) is a structure containing certain important information about the process. Each process has it's own PCB (Process Control Block) to represent it in the operating system.
  • PCB(Process Control Block) contains information regarding the execution state of the program, memory management information and CPU scheduling information, etc.
PCB(Process Control Block) contains several types of information depending upon the process to which PCB belongs.
  1. Process state.
  2. Process number or ID.
  3. Pointer.
  4. Program counter.
  5. Register.
  6. I/O information.
  7. Accounting information.
  8. List of open files.
the-general-view-of-PCB
the general view of PCB

1.  Process state

It tells the state of the process. Or we can say that it tells the present activity of the process. It can be running, waiting, etc.

2.  Process number or ID

Each process is identified by its process number, called the process identification number (PID).

3.  Pointer

This is a pointer to PCB (Process Control Block) of the next process in the ready queue.

4.  Program counter

The program counter holds the address of the next instruction to be executed for that process.

5.  Register

This specifies the register that is used by the process.

6.  I/O information

This information includes the list of I/O devices used by the process, the list of files, etc..

7.  Accounting information

The time limits, account number, amount of CPU used, process number, etc. Are all a part of the process.

8.  List of open file

These are the different files that are associated with the process.

Co-operating process

  • A process is said to be a co-operating process if it can affect or be affected by the other process executing in the system. On the other hand, is a process that cannot affect or cannot be affected by the other processing process.
  • Any process that sharing data with other processes is a co-operating process.