Each process in an operating system is represented by a Process Control Block (PCB). The PCB is a data structure that contains information needed to manage a particular process, and serves as the manifestation of a process in the OS. A PCB consists of pointers, process state, program counter, CPU registers, CPU scheduling information, memory management information, accounting information, and I/O status information. This information allows the OS to control, schedule, and terminate processes.

1. PRESENTATION
ON
PROCESS CONTROL BLOCK
VIKAS KUMAR SHRIVASTAVA
BCA HONOURS
First Year
BCAH1CA-16023
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2. WHAT IS PROCESS CONTROL BLOCK ?
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3. PROCESS CONTROL BLOCK
 Each & every process in the operating
system is represented by PROCESS CONTROL
BLOCK.
 Process Control Block also known as
Task Controlling Block or Process Table.
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4. PROCESS CONTROL BLOCK
 Its is a data structure in the operating
system kernel containing the information
needed to manage a particular process.
 The PCB is “ the manifestation(visible) of
a process in an operating system”
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5. BLOCK DIAGRAM OF PCB 5

6. PROCESS CONTROL BLOCK (PCB)
PCB consist of following information~
 Pointer .
 Process state .
 Program counter .
 CPU register .
 CPU scheduling information .
 Memory management information .
 Accounting information .
 I/O status information . 6

7. PROCESS CONTROL BLOCK (PCB)
 POINTER ~ Its contains the address of another
process which is present in the ready queue
 PROCESS STATE ~ Its contains the information
about the state of the process i.e.,
 NEW
 READY
 RUNNING
 WAITING
 HALTED
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8. PROCESS CONTROL BLOCK (PCB)
 program COUNTER - The counter specifies the
address of the next instruction to be executed.
 CPU REGISTERS - The register vary in number and
type depending in the type of computer
architecture, they include:
 Accumulators, index register, stack pointer and
general purpose registers 8

9. PROCESS CONTROL BLOCK (PCB)
 CPU SHEDULING INFORMATION –
This information includes
 Process priority
 Pointer to scheduling queues
 Other scheduling parameters.
 MEMORY MANAGEMENT INFORMATION –
This information includes
 Value of base and limit of registers
 Page tables
 Segment tables
 Depending on the memory system used by the
operating system.
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10. PROCESS CONTROL BLOCK (PCB)
 ACCOUNTING INFORMATION – This information includes
 amount of CPU and real time used
 time limit
 account number
 job or process number etc.
 I/O STATUS INFORMATION - This information includes
 list of I/O devices allocated to the process
 list of open files etc.
Hence, the PCB serves as the repository for any
information that may be vary from process to process.
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