Process

Units of computation, execution of codes in which is controlled by the OS scheduler,
inter-process communication, resource-manager, system-memory and other system-
resources (such as network, file, display or printer) access control mechanisms and are
processed concurrently.

Process Control Block
‘| A data structure having the information using which the OS controls the process state.

[| Stores in protected memory area of the kernel.

ட consists of the information about the process state

Information about the process state at Process Control Block...

ட Process 112.

ட 100085 priority,

ட Parent process (if any),

ட Child process (if any), and

ட Address to the next process PCB which will run,

‘| allocated program memory address blocks in physical memory and in secondary (virtual)

بم

memory for the process-codes,

allocated process — -snecific data address blocks
allocated process

ப ப

-heap (data generated during the program run) addresses,

ന
]

allocated process
ட allocated

-stack addresses for the functions called during running of the
process, addresses of CPU register-save area as a process context
represents by CPU
registers, which include the program counter and stack pointer
[1 allocated addresses of CPU register -save area as a process context [Register-contents
(define process context) include the program counter and stack pointer contents]

— process -state signal mask [when mask is set to 0 (active) the process is inhibited from