Process States | Process State Transition Diagram

Summary

This video from 'Making It Simple' series delves into the process states in operating systems, explaining the lifecycle of a process from creation to termination. It outlines the five primary states: New, Ready, Running, Waiting/Blocked, and Terminated, detailing how processes transition between these states. The video also touches on additional states like Suspend Waiting and Suspend Ready, which are used to manage processes when memory is limited. Aimed at providing a clear understanding of process state transitions, the video invites viewers to engage with comments and suggestions.

Takeaways

• 🌐 The video discusses the process states in an operating system, detailing the lifecycle from creation to termination.
• 🆕 A process is initially in the 'new' state when it's created but not yet in main memory.
• 🟢 Once the process is loaded into main memory, it transitions to the 'ready' state, waiting for CPU assignment.
• 🏃‍♂️ The 'running' state is when the CPU begins executing the process's instructions line by line.
• 🔄 A process can move back to the 'ready' state if preempted by a higher priority process or after completing a time quantum.
• ⏸ The 'waiting or block' state occurs when a process requires I/O operations or other events that the CPU cannot wait for.
• 🔄 Processes in the 'waiting' state are in a queue and must return to 'ready' before they can be scheduled for execution again.
• 🏁 The 'terminated' state signifies the end of a process's lifecycle, where it's removed from main memory and its structure is deleted.
• 🔄 Additional states like 'suspend wait' and 'suspend ready' are used to manage processes when the waiting or ready queues are full.
• 💾 Processes in 'suspend wait' or 'suspend ready' are moved to secondary memory to free up space in main memory.
• 🔄 The video concludes by encouraging viewers to engage with the content, ask questions, and subscribe for more informative videos.

Q & A

What are the five primary states in the process life cycle?

The five primary states in the process life cycle are: New, Ready, Running, Waiting or Block, and Terminated.

What happens when a process is in the 'New' state?

In the 'New' state, a process is just created. This occurs when a program is executed and the operating system picks it up from secondary memory to place it in main memory (RAM).

What is the significance of the 'Ready' state in a process's life cycle?

The 'Ready' state signifies that the process has entered main memory and is prepared for execution. It waits in the ready queue until the CPU is assigned to it for execution.

Can you explain the 'Running' state and how a process can transition back to the 'Ready' state from it?

The 'Running' state is when the CPU starts executing the process. A process can transition back to the 'Ready' state if it is preempted by a higher priority process or if it has completed its time quantum in a time-sharing system.

What causes a process to move to the 'Waiting or Block' state?

A process moves to the 'Waiting or Block' state when it requires an input/output operation or another event that the CPU cannot wait for, thus stopping the execution of the process.

How does a process transition from the 'Waiting or Block' state back to the 'Ready' state?

After completing the required input/output operation or event, a process in the 'Waiting or Block' state moves to the 'Ready' state, where it is scheduled for execution again.

What is the final state of a process called, and what happens during this state?

The final state of a process is called 'Terminated'. During this state, the process structure and the process control block are deleted, and the process is terminated by the operating system.

What are the additional states of a process mentioned in the script, and why are they necessary?

The additional states mentioned are 'Suspend Wait' and 'Suspend Ready'. They are necessary to manage processes when the main memory's waiting queue or ready queue is full, allowing processes to be temporarily moved to secondary memory.

How does a process in 'Suspend Wait' state get back to the 'Ready' state?

A process in the 'Suspend Wait' state first goes back to the 'Wait' state once its I/O operation is completed. From there, it moves to the 'Ready' state to be scheduled for execution again.

What is the role of the 'Suspend Ready' state in managing process queues?

The 'Suspend Ready' state is used when the ready queue is full, and a high-priority process needs to be added. Low-priority processes are moved to 'Suspend Ready' in secondary memory to make space, and they return to the 'Ready' queue when space becomes available.

Can a process in 'Suspend Wait' go directly to 'Suspend Ready' if the 'Wait' queue is still full?

Yes, if a process in 'Suspend Wait' completes its I/O operation and the 'Wait' queue is still full, it can directly go to 'Suspend Ready' and then to 'Ready' when space is available.

Outlines

00:00

🔄 Process State Transitions Explained

This paragraph introduces the concept of process states within an operating system. It outlines the five primary states a process goes through from creation to termination: new, ready, running, waiting or blocked, and terminated. The process begins in the 'new' state when it's created but not yet in main memory. It then moves to the 'ready' state when it's loaded into main memory, waiting for CPU assignment. Once the CPU starts executing the process, it enters the 'running' state. The process can return to the 'ready' state if it's preempted by a higher priority process or if it requires I/O operations, moving it to the 'waiting or blocked' state. Finally, after execution, the process transitions to the 'terminated' state, where it's removed from memory. The paragraph also mentions additional states like 'suspend ready' and 'suspend weight', which are used when the ready or waiting queues are full, moving processes to secondary memory until space becomes available.

05:00

🛠 Advanced Process State Management

The second paragraph delves into the advanced aspects of process state management, focusing on the 'suspend ready' and 'suspend weight' states. It explains how these states are utilized when the main memory's ready or waiting queues are full. In such cases, processes are moved to secondary memory to free up space in the main memory. The paragraph provides an example where a process in the 'suspend weight' state completes its I/O operation but cannot return to the 'ready' state due to a full waiting queue, hence it moves to 'suspend ready'. Once space is available in the main memory, these suspended processes are moved back to the ready queue to await CPU scheduling. The paragraph concludes with an invitation for feedback and suggestions, encouraging viewers to comment on topics they'd like to see covered and to engage with the content by liking, sharing, and subscribing to the channel.

Keywords

💡Process States

Process States refer to the different stages a process goes through from its creation to termination. In the context of the video, these states are crucial for understanding how an operating system manages processes. The script outlines five primary states: New, Ready, Running, Waiting or Block, and Terminated. Each state represents a phase in the life cycle of a process, and the transitions between these states are governed by specific conditions and requirements, such as CPU availability or the need for I/O operations.

💡Process Control Block (PCB)

A Process Control Block is a data structure used by an operating system to store the context of a process. Although not explicitly detailed in the script, it is implied as a foundational concept for understanding process states. The PCB contains information necessary for the management of the process, such as its state, priority, and resource requirements. When a process is created, its PCB is also created, and it is updated as the process transitions through different states.

💡New State

The New State is the initial state of a process when it is first created but not yet ready for execution. In the script, it is mentioned that a process enters this state when a program is executed, and the operating system picks it up from secondary memory to place it in the main memory. This state signifies the birth of a process in the system's memory, preparing it for further transitions.

💡Ready State

The Ready State is when a process is in the main memory and is waiting for the CPU to assign it for execution. The script explains that many processes can be in the Ready State, forming a queue, as they await their turn to be executed. This state is a critical part of process scheduling, where the operating system decides which process to run next based on factors like priority and resource availability.

💡Running State

The Running State is when the CPU is actively executing the process's instructions. The script describes that a process transitions to this state from the Ready State once the CPU is assigned to it. While in the Running State, the process can be preempted by a higher priority process or may need to wait for I/O operations, causing it to transition back to the Ready State or to the Waiting or Block State.

💡Waiting or Block State

The Waiting or Block State is when a process is waiting for an I/O operation or some other event to complete before it can continue execution. As mentioned in the script, the CPU cannot wait for these operations, so it halts the process's execution. The process remains in the main memory but is not actively running. Once the required operation is completed, the process can return to the Ready State to be scheduled for execution again.

💡Terminated State

The Terminated State is the final state of a process after it has completed its execution. The script explains that in this state, the process structure and its PCB are deleted by the operating system, marking the end of the process's life cycle. This state is significant as it signifies the cleanup and release of system resources that were allocated to the process during its execution.

💡Process State Transition Diagram

A Process State Transition Diagram is a visual representation that illustrates the movement of a process between different states. The script mentions this diagram as a tool to understand how a process transitions from the New State to the Terminated State, passing through Ready, Running, and Waiting or Block States. This diagram is essential for grasping the dynamics of process management within an operating system.

💡Suspend State

The Suspend State, which includes Suspend Weight and Suspend Ready, is an additional state not actively running in the main memory but is stored in secondary memory. The script uses this concept to explain how processes are managed when the main memory is full. Processes in Suspend State are not immediately available for execution but can be resumed when space becomes available or when I/O operations are completed.

💡Time Quantum

Time Quantum refers to the amount of CPU time allocated to a process before it is preempted and the CPU is assigned to another process. The script touches on this concept in the context of time-sharing operating systems, where a process in the Running State is executed for a specific time quantum before it may be sent back to the Ready State to allow other processes to run. This scheduling technique helps in fair distribution of CPU time among processes.

Highlights

Introduction to process states and their transitions in operating systems.

There are five primary states in the process life cycle: new, ready, running, waiting or block, and terminated.

The process state transition diagram or process life cycle is explained.

A new process is created when a program is executed or an application is opened.

Process control block is created when a process enters the new state.

A process transitions to the ready state when it enters the main memory and is prepared for execution.

Processes in the ready state wait in a queue for CPU assignment.

A process moves to the running state when the CPU begins its execution.

A running process can return to the ready state if preempted by a high-priority process or after a time quantum.

The process enters the waiting or block state if it requires input/output operations while running.

Processes in the waiting state are in a waiting queue and must return to the ready state after completing their required operations.

A process transitions to the terminated state when the CPU has fully executed its code.

In the termination state, the process structure and process control block are deleted by the operating system.

Additional states include suspend wait and suspend ready, which are used to manage processes when queues are full.

Suspend wait state is for processes that need to wait for I/O operations and are moved to secondary memory.

Suspend ready state is for processes that are moved to secondary memory when the ready queue is full.

A process in suspend wait can go directly to suspend ready if the wait queue is still full after I/O operations.

Encouragement for viewers to comment on topics they want to learn about, ask questions, or share suggestions.

A call to action for viewers to like, share, subscribe, and enable notifications for new video updates.

Transcripts

hello and welcome to making it simple

in previous videos about process we have

seen about process

and process control block today in this

video we will see about process states

the process right from when it is

created until it gets terminated

after execution it goes through various

states

we are going to study these states and

how and why the process transits from

one state to other

without wasting any time let's start the

video after this short intro

there are primarily five states in

process life cycle

which are as follows first is new

next is ready then comes running

then the next one is weight or block

and the last one is terminated and this

is how the transition happens between

the states

this complete diagram is called process

state transition diagram

or we can also call it process life

cycle

let us simplify each state one by one

first state is new when a new process is

just created

it is present in this state for example

when you write some program and save it

it is stored in hard disk that is

secondary memory

when we execute that program an

operating system just picks it up from

the secondary memory

to place it in main memory at that time

when it is just picked up to get placed

in main memory

that is ram we can say that process is

created and that state is the new state

another example can be when you just

open any application

let's say google chrome or vmware the

process is just created at that time

that's when it is in the new state when

process gets to new state

the process structure is created and

process control block is created

when these are created it becomes

complete or ready

it then transits to ready state

we can say the process is in ready state

when it enters the main memory or ram

and is ready for execution this state is

the ready state

process waits in ready state until cpu

is assigned to it for execution

many processes can be present in ready

state or a ready queue

waiting for their execution

now after waiting for some time in ready

queue the process will be scheduled for

execution

the cpu will start executing the process

when the cpu starts executing the

process

at that time process transits to the

running state

where the cpu executes process

cpu will execute line by line the

executable code

now again it can go back to ready state

from running state

how let us see let us say our process is

getting executed by the cpu

and a high priority process comes in

main memory or ready queue

as we have seen cpu will give importance

to high priority process

so it will stop executing our process

and start the execution of high priority

process

our process will get preempted that

means it will be force stopped

and it will go back to the ready state

or as we have seen in time sharing

operating system

a process is executed for particular

time quantum

then next process is executed in that

case also process can go to ready state

from running state

and wait in ready state for its turn for

execution

another thing that can happen while

process is in running state

is it can require some input output

operation or some other event

cpu cannot wait till that time so the

cpu stops the execution

and process goes in waiting or block

state

where it will complete the input output

operation or other required event

here also there is a waiting queue where

multiple processes are present

processes that are in waiting queue are

present in main memory only

after completing required operation it

directly cannot go to running state

it has to go to the ready state where

again it will get scheduled for

execution

another thing that can happen in running

state is cpu will completely execute the

process

it will execute the complete executable

code

process will get out of the main memory

then the process will get completed and

transit to the termination state in

termination state

the process structure will get deleted

as well as the process control block

will get deleted

and process will get terminated by

operating system

these are the primary process states

there are some additional states

one state from that is suspend weight

and another state is suspend ready

let us understand with example

let us say many processes need i o

operation

so cpu sends them to weight and block

state

they are stored in weight q which is

present in ram

we know that ram or main memory is

limited

so in worst case the weight q will get

full

now where to keep the processes that

will come to weight state

to tackle this situation processes are

transferred to suspend weight state

the suspend weight is in secondary

memory so these processes are

transferred to secondary memory

so that we can make space in weight

state or weight q

once i o operation is done it can get

back to weight state

and then back to ready state from here

it can again get scheduled

now let's take a look at suspend ready

similar to previous situation if ready q

is completely filled with processes

and a high priority process arrives

as it has high priority it must be added

to ready q

so in such case other low priority

processes

are transferred to suspend ready suspend

ready is also present in secondary

memory

like suspend weight when ready q has

enough space

processes present in suspend ready are

transferred back to ready q

one more situation that can occur with

process in suspend weight is

let us say a process in suspend weight

has completed i o operation

it needs to get back to ready state but

the weight state or weight queue is

still full

and there is no room for any process

then how will it get to ready state

in this situation the process can

directly go to suspend ready

and from there it can go to ready state

this is complete overview of process

state transition diagram

so we are done with process states and

process state transition diagram

hope you all understood the concept

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on a particular topic related to

operating system

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suggestions feel free to comment

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