Process Control Block PCB

 What is PCB(Process Control Block)?

PCB is a data structure in the OS and it contains all the information about a process.The following information is stored in PCB;

  • Process ID

When OS converts a program into the process then OS assign process ID to each process.

  • State of the process

PCB maintains the record of the state of each process. A process can be in new, waiting, ready, running and can be in the terminated state.

  • Program counter
  • Priority of the process

Sometimes we need to assign priority to each process. For example in priority scheduling, OS developers maintain the priority for each process.

  • Process Privileges

PCB maintains the record of all the privileges assigned to each process. For example privileges of Read, Write, Copy etc.

  • Memory management information

PCB maintains the record that how much memory is available for use and how much memory is allocated to the processes etc.

  • I/O status information
  • Interprocess communication information\

Sometimes a process works independently and sometimes some processes work together to achieve a big task.

  • Accounting information