PROCESS CONTROL BLOCK

PROCESS CONTROL BLOCK

 Process Control Block (PCB, also called Task Controlling Block, process table, Task Struct, or Switchframe) is a data structure in the operating system kernel containing the information needed to manage a particular process. There is a Process Control Block for each process, enclosing all the information about the process. It is a data structure, which contains the following :

 

• Process State - It can be running, waiting etc.
• Process ID and parent process ID.
• CPU registers and Program Counter. Program Counter holds the address of the next instruction to be executed for that process.
• CPU Scheduling information - Such as priority information and pointers to scheduling queues.
• Memory Management information - Eg. page tables or segment tables.
• Accounting information - user and kernel CPU time consumed, account numbers, limits, etc.
• I/O Status information - Devices allocated, open file tables, etc.