4.8 Semaphores in Process Synchronization in OS

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[@KNOWLEDGEGATE_kg]

For complete Operating System, check out this video: kzbin.info/www/bejne/rqjCgKiFnc-Uq9k

[@mridulkumar786]

my left ear understood everything properly :)

[@VanBhardwaj]

I'm using samsung buds +. I almost got a heart attack thinking that my right earbud has broken down.

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@@VanBhardwaj ameer log 😅🙏

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@@VanBhardwaj same I was connected with my Bluetooth leaf bass 😂

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Thought I lost my earphone

[@Jeevan_prakash]

@@ankithanaik3327 😁😅

[@shubhamgoyal2622]

You have made this topic so easy that it has actually infused a great deal of interest in me and it no more makes me dull.👏

[@KNOWLEDGEGATE_kg]

Hello Shubham, we are happy that we could help you. :)

[@vibhorgoyal97]

Great!! You make me nostalgic to my jee preparation days ! wonderful way of teaching

[@kamaljitpati]

Not only this video, I like all your videos. Literally I love your teaching style, i hope one day i will become like you.

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[@omop5922]

So have u become like him?

[@jagdishdora5199]

Dear Sir Greetings from the Doon Valley Plz accept my heartiest congratulations for the great service you are providing to the students' community. I am also a teacher by hobby and take great help from yr videos in helping the students .Right now I am stuck with a confusion over the exact meaning of 'T' used in last while(T) of do while loop in your video explaining the semaphores for process synchronization . Thanking you Sir yours truly J.R.Dora,Dehra Dun)

[@rupammedhi9943]

Sir.. Books main intna fuzzy lagta hai. Par apke samjhane sey ekbar main hi dimag main ghush jata hai.. Aap bohut actha parhate hai.. Bohut kuch sikhne ko mila hai.. Bohu bohut dhanyabad sir..

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So many utube videos So many tutors But ur way is unique sir Take a bow... ur biggest fan here. Through your videos today i teach my frnds and top my class Thanks a lot .

[@muhammadroshan7315]

*take a bow nhi angrez takes hota ha. kia ab woh tre sajday shuru kr de kiyu ke tu us ka fan ha

[@saroshfaisalkhan3531]

Excellent tutorial sir...Allah tala aapko aur apki teaching ko bahot bahot roshan kare. Allah ne aapko mere concept clear krne ka source banaya sir..Mujhe samajh nhi aa rha k aapko thanks kaise kahun..but finally mujhe wo concept clear ho gaye jo mujhe other lecttures k through nhi ho pa rahe the...Now I am very happy..Bahot sari duaein aapke liye..Thank you sir.

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Moral of the story is that yeh teacher mast hai. Awesome explanation skills!

[@prathameshmestry9482]

english and hindi k mixture ki vajah se jyada ache samaj main aata hain

[@yogeshsurve7864]

Prathamesh Mestry true bro🤞🤞✌️✌️🤘

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Im from Bangladesh with little hindi background and I agree with u

[@GeorgeTsiros]

i don't speak hindi and i understood about half of the english he said, even so, i understood more than enough to continue studying

[@adityarajora7219]

George Tsiros: How you able to understand Prathamesh Mestry's comment?

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@@adityarajora7219 that is some God level IQ of yours

[@sonicapriyadarshini6613]

Seriously, Your teaching way is amazing. I came to understand all those topics easily which were quite impossible for me. After watching your different lectures I was unable to stop myself to mention a comment. Thank you so much and please upload other related topics of computer science also.

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This is really a tough topic but efforts from knowledge gate are really very helpful. Clarity of concepts and easy verification of true and false solutions. Thank you &Keep it up :)

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really India need teacher's like you sir🙏🙏

[@nidhinandani1827]

I have ever seen a teacher like u in my life. U use to clarify the root of topic so clearly that even a weak student can grasp it.Thanks once again!!!!!!

[@manishmaithani398]

Sir, you explained the Semaphore in a very good fashion. But i want to add small point. 1. wait and Signal are system calls and we ensure that there is not interrupt (preemption) while they execute. Means at any time, only one process can execute wait or signal (even many processes are trying to access them). 2. To ensure that we disable interrupt, as int mask = disable() // as the very first line in wait and signal function. (unix OS) 3. And at the end, we restore the interrupt (preemption) restore(mask); // very last line of wait and signal command (unix OS)

[@kangkanjsaikia7385]

You are a good teacher.Please keep up the good work.Your knowledge will help millions of students.

[@manoharpanwar1265]

i am the person who is studying first time bcs i am from electronics background we didnt have OS at that time .Bro. your teaching way with so much energy and one thing is best is you go back and forth and revise all topics in all episode that is best thing .Thank you fully appreciate your hardwork :)

[@nandishbijinelly182]

Excellent Work Sir. And your Smile at the end of every video keeps me confident and encouraging sir. Keep the good work going. Thank You Sir.

[@satyajeetjha1681]

I am not a gate aspirant but it will be really great if you cover the entire operating system and dbms .you explain things really well .

[@samsungyou2010]

Nice Explanation. This is the simpler version of the topic that everyone can understand. Thank you so much for making it simple. God Bless you.

[@pc0riginal870]

sir in your videos sound will come in the only left-hand earphone,not in right-one

[@dinkyacharya113]

Yes tats true

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The prophecy is upon us

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*Sound is coming!!

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Thank god I saw ur comment I thought my earphones are not working 😂

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my earphones left one is broken so i cant even hear a thing lmao

[@pushprajgupta1604]

I can say that is the perfect lecture on os....ur way of xplanation is very impressive...........hats off 2 u "SIR"....Keeping doing this that will help us in interviews also.I've a request also please upload IPC lecture if possible(pipe,fifo,msgqueue,shared object etc)...At last but not the least thanks to u frrom the bottom of my heart.........

[@PiyushGupta361]

these are the best lectures on operating system IPC, i have never seen before.....thank u so much sanchit sir.........

[@meetpanchal4298]

he really deserves a big award, im understanding concepts so welll.thanks sir,have a great life ahead.

[@awesometricks2374]

sir your explaining ability is awasome.

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Ur the best teacher of os , dld , and DBMS I'll clear all my os concept with the help of your video sir thanks 🙏❤️

[@KNOWLEDGEGATE_kg]

Thank you so much for your valuable feedback❤ Keep learning & supporting! You can also check out our course for all Computer Science subjects, sharing the link below: www.knowledgegate.in/learn/Zero-to-Hero-in-Computer-Science

[@supongmenwalling6929]

it took me a lifetime to understand semaphore concept until I saw your video. Beautiful Explanation

[@abhisheksoni5177]

sir i have to say ! you are the best teacher of whole you tuber ..sir why did you not make more videos for operating system and also for other subjects. sir you have impressed me infact many student of my class friends also ...i regularly share your videos to my friend ...thank you sir

[@shubhamhapse6498]

something is wrong (or I missed something..) lets consider one use case-> There are 2 processes and context switch happed after while(s

[@siddhantsingh4870]

Wait and signal are atomic operations i.e once started they can't be interupted.

[@siddhantsingh4870]

So wait will be executed and p2 wont come in between while statement

[@NomadStriver]

sir this is the best video lacture......

[@nasrisami17]

It's a sarcasm !!

[@adityarajora7219]

Chutiya nandan!!

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Kids don't know the subject and don't know how to teach. Men know the subject but don't how to teach. Legends know the subject and knows how to teach. You are a legend sir!

[@Engineerblogbihar]

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[@monikagoel988]

Excellent lecture. Thanks Mr. sanchit Jain for your superb explanation.👍

[@mukhaambikavaradavenkata8045]

Sir you are the best teacher ever i saw.very good explanation. include remaining topics also sir

[@shriram6123]

Ye batana 12:00 DOUBT :👀👀👀👁️👁️👁️👁️ ❔❓❔❓❔❔❔❓❔❔ Agar process p1 execute karte time semaphore ko 0 karde par use store na karaye to?? S=S-1 ---> isme teen micro instuction honge na ---> load S Decrement S Store S (bas ye wali execute hone se phele hi control kisi or process ke pass chala jaye) I think is case me ek se jada process ek sath CS me aa jayege or mutual exclusion nahi ho payega.❓❓❓❓❔❔❔

[@mohsin7343]

Sir you are looking really handsome in this video..✨✨✨ And your teaching style is as everytime TOP NOTCH QUALITY 💯💯💯💯

[@KNOWLEDGEGATE_kg]

Haha Thank you so much❤ keep supporting & stay connected for more amazing contents 👍😊 You can also check out our course for all Computer Science subjects, sharing the link below: www.knowledgegate.in/learn/Zero-to-Hero-in-Computer-Science

[@awadheshamar6012]

awesome video.Thanks a lot.I am not from computer background but working in IT sector.I understood completely because way of teaching is awesome.

[@KNOWLEDGEGATE_kg]

thanks a lot awadhesh bhai... will do more hard work...

[@deepakbaghel9984]

I saw all the videos of OS from your videos...........GREAT EXPLAINATION>>>>>>>>and thanks ALL THE BEST

[@gameclip9612]

If such type of finest teacher are available on youtube then why we need GATE coaching center. we love you sir . After watching your videos I started to love engineering .

[@tracimorrison7272]

English subtitles would really help! The language mixture was extremely confusing and hard to follow. Subtitles (or redo it in just 1 language) would greatly improve.

[@KNOWLEDGEGATE_kg]

Hello Traci, sorry for inconvenience and soon we are going to create an separate playlist(english). :)

[@bigray712]

when will it be available? interesting topic, not much discussed on youtube

[@helloansuman]

best teacher ever. please upload more. Eager to wait for more videos.

[@swathi1319]

This is so good. I don't understand Hindi 100% but the way u xplained it was awesome. It helped me a lot. Thanq so much

[@KNOWLEDGEGATE_kg]

Hello Swathi, sorry for the inconvenience, but we are glad that we could help you and would like to hear more from you :) we upload more topics every week, Please subscribe this channel for best GATE tutorials.

[@Akashpagol]

Go and watch "Ek shaam Premchand ke naam" ... Will help with your Hindi. Tickets Rs 300 onwards. BTW ...Very good explanation of semaphores. Very helpful!

[@garimasancheti3518]

you have taught the topics extremely well. can you upload videos on banker's algorithm and monitors in operating system. looking forward to ur videos.need it badly for exams.

[@santasingh9045]

easily the best explanation on youtube. hats off sanchit sir

[@Prabhat56682]

Sir you are Best teacher for conceptual subjects in computer science branch, Thank you so much for this vedio.

[@tarkatavines4354]

Thank you sir.. I'm here just beacause of you..i attended full 28 marks from os today..really the way you simplify the problems really hats off..!! I got interest in os just only for you..thank you so much sir..! Take a bow 🙂

[@rajandeepgill111]

Sir your way of explanation is very good... it makes topic very easy. Thank you Sir for all lectures...

[@KNOWLEDGEGATE_kg]

Hello Rajandeep, we truly appreciate your kind words for our efforts. :)

[@mudassarakbarali1188]

You are legend professor keep it up you are the best :)

[@KNOWLEDGEGATE_kg]

Thanks Mudassar for such a delightful comment, we will give our best. :)

[@vivekkhatri9769]

it is very usefull for us to understand easily ..we would love to see your videos to understand the main topics of OS ...thanks

[@vivek1692asd]

Best lectures !! Upload more lectures of algorithms and Computer Networks...Mazaa aa gya..

[@arjitdabral8449]

I wish my University professors taught like this guy 💯

[@shriram6123]

Ye batana 12:00 DOUBT :👀👀👀👁️👁️👁️👁️ ❔❓❔❓❔❔❔❓❔❔ Agar process p1 execute karte time semaphore ko 0 karde par use store na karaye to?? S=S-1 ---> isme teen micro instuction honge na ---> load S Decrement S Store S (bas ye wali execute hone se phele hi control kisi or process ke pass chala jaye) I think is case me ek se jada process ek sath CS me aa jayege or mutual exclusion nahi ho payega.❓❓❓❓❔❔❔

[@mohitchawla1878]

Sir I have seen many of your videos and u make concept look so simple..thank you.. But sir, I have one request, if u can make series of videos on computer architecture and organization. There are very little quality tutorials of this subject on KZbin especially if GATE is concerned.

[@erifa3368]

I have my OS paper tomorrow. Thanks Loads :) your videos are helpful. :)

[@whatnextforfree8113]

don't be panic sir , take it easy , you are really doing well.

[@arpitkhare4286]

The first video of a legend!

[@keyurdhanesha4044]

Sir,i found your tutorial videos very helpful in having concepts clear.I am going to suggest this channel to all my friends.I request you to explain Bakery Algorithm which is studied before semaphore.Please consider my request and try to upload it soon.Thank you.

[@KNOWLEDGEGATE_kg]

Hi Keyur, Thank you so much for your encouraging and delightful words, we are glad that we could help you. We are working on "Bakery Algorithm", Please subscribe our channel to follow all updates. :)

[@kartikpaigwar7921]

I used to judge tutorials just from language today this video proved me wrong, though it is in hindi + english but very precise in explaination, i hope if i get lecture series like this for every subject i will never go to college haha

[@devganshubham]

finally I can clear my Exam your videos are great, i cleared DBMS using your videos..thanks alot :)

[@KNOWLEDGEGATE_kg]

Congratulations Shubham ! We are glad that we could be helpful :)

[@Anirudh53615]

Thank You sooo much for such Videos sir you helped me alot during my exams time...u helped me cover the topic of Normalisation once and now you helped me in the topic Process Synchronization..Thank you soo much

[@kapilpareek3954]

sir nice video u r a best teacher. and sir plz never change your teaching style .sir you use a understand able way.

[@devendrayadav-um3nj]

jain sir... u r too good.... I m gonna recommend this to all my friends... plz make more videos

[@sanjeevgupta7646]

sir u are great gate guru...... thank u upload more and more so that hm apse kuch sikhe....

[@sanjeevgupta7646]

thnku bhaiya ,I m waiting for your next . wish u all d best for the upcoming videos, come soon.you are doing great job for us and thnk u again....

[@adityarajora7219]

You are actually better than the RavindraBabuRavula

[@8bit_hero850]

exactly...

[@vagelisd6508]

everyone is better than RavindraBabuRavula, he's like the scotty pipen of 90s bulls

[@Anand-wi4yb]

You can't compare him with Ravindrababu Ravula.

[@hirakmondal6174]

Its like comparing Netaji Subhas and Vivekanada... PS--> Ravibabu and Sanchit jain both are great and should never be compared but respected. Peace!

[@anweshasarkar1288]

Ravindrababu Ravula is also a best one for instructing computer engineering topics but there is a very little problem in their video organization nothing in his providing lecture.sanchit bhaiya is so much best in his making,instructing and organising videos in front of viewers.sanchit bhaiya is the top most lecturer in inmparting computer core topics just like OS,COMPUTER ARCHITECTURE etc. And in case of program oriented also just like DBMS.SO PLEASE do not compare one best teacher to another one best teacher just respect these teachers who are suitable originally to be called as Sir .Both they are best.

[@sushmat6470]

That was an awesome explanation. You made the concept very clear for me!! Thanks, much!!

[@RahulYadav-zw6bw]

amazing way of teaching. I really impressed. Its a first time I am taking lecture through net and its very very very helpful for me. Thankyou so much sir.

[@anuragsharma4435]

your lectures are very easy to understand even for a below average student . sir can you please upload videos on deadlock .

[@siddharths5652]

Go to settings->Accessibility and switch on mono audio to get audio in both earphones

[@droidfever7267]

did that already 😉 😉

[@channelname8300]

the video for which you specially sign in to like it....very well elaborated.

[@KNOWLEDGEGATE_kg]

Hi Shivam,Thank you so much, would like to hear more from you. We upload more topics every week, Please subscribe this channel for best GATE tutorials.

[@goldenpunk9k]

my left ear appreciates everything u saif... thnk u good sir

[@KNOWLEDGEGATE_kg]

Thank you so much rahul for showing gratitude :)

[@sudhanshujain6384]

@@KNOWLEDGEGATE_kg I think he means to say that the content is very good but but you should switch the audio from mono to stereo, its kind of annoying!

[@smitakhanna-vu6um]

​@@sudhanshujain6384aapne 2 saal baad reply diya 🤣🤣🤣

[@sudhanshujain6384]

@@smitakhanna-vu6um aapne bhi to 4 saal baad reply diya. I went through this video for my Engg exam, I guess most of us are here for that only :)

[@smitakhanna-vu6um]

@@sudhanshujain6384 I meant as in, the gaps between the msgs, it was funny lol. It wasn't to mock you, sorry.

[@shishirmohire9789]

what if two processes are waiting simultaneously at wait(s) and signal(s) is executed at that time. Won't those two processes enter in the critical section at a time.

[@ayushvijayvergia7266]

Sir, all your lectures are very good. You have explained everything in an easily understandable manner.

[@sheshanath]

Thank You Sir. Your Language is very easy to understand.

[@shifamomin6547]

sir plzzz make videos on M-way tree..and how to built B-tree....I have my papers after 10 days....I find your videos very helpful and i thank u from bottom of my heart....sir pllz its my request..

[@yogendragangwar9795]

Excellent description about the topic as you have been shared on youtube in all video's. Thanks a lot.

[@pratikaagnihotri2346]

Sir, your explanation is truly magical...you make topics too simple, I love to watch ur videos

[@rajattyagi9961]

Sir Your explanation is very great before i was having lot of confusion but now its all resolved. Thanks for making these videos.

[@sonianazir5335]

Your method of teaching is veryyyy goooooooood

[@priyankamalviya5834]

Will you please upload the examples of fork system call which are asked in previous year gate question papers. Please explain it in details none of any you tube channel is talking about fork system call if anyone is explaining they are explaining easy examples but I need some complicated examples of fork system call for example - anding&oring simultaneously , loops etc And thanks to you sir you are giving your best the way of explanation is much more better it is directly striking and examples you give during expalnation of any topic are best 👌 like kitna khaya , and so on

[@imalinasahoo]

My semester exams are on 14 November. And here I am, I never understood semaphores in my college and your video made it possible. Thank you sir 😍

[@imalinasahoo]

@devendra patra : Exactly 😅

[@shivarammuthukumaraswamy7164]

14th?u study in srm huh?

[@rahuljangir7196]

Sir, please make video on monitors in OS Thanks

[@RupeshKumar-kq1bs]

Settings->additional settings-> accessibility-> mono audio "enable"

[@KNOWLEDGEGATE_kg]

😀

[@harshal5464]

you are the best professor I ever got on KZbin !!!

[@KNOWLEDGEGATE_kg]

Glad i could help and thanks for your valuable support

[@harshal5464]

Sir can u upload data structure and algorithm also??

[@harshal5464]

And some important gate questions of Theory of computation only solved questions videos

[@harshal5464]

KNOWLEDGE GATE Sanchit Jain Sir you are the best professor of Computer science !! without u operating system was just a name for me u taught it so well !!!

[@KNOWLEDGEGATE_kg]

yup harshal will do that very soon :)

[@turrinaga8533]

best videos i have ever seen..very easy to understand..please also make new videos..

[@KNOWLEDGEGATE_kg]

Hi Buddy, we truly appreciate your kind words for our efforts.We upload more topics every week, Please subscribe this channel for best tutorials.

[@Gauravsingh-cx7ny]

Great work Best wishes for your future endeavors 😊

[@KNOWLEDGEGATE_kg]

Thanks a lot❤ Keep supporting & stay connected 👍😊

[@saurabhverma3453]

sir ur teaching style is too good and lectures are very helpful .....plz upload more lectures....

[@RanjanKumar-hs5tt]

videos are really very helpful and effective as compared to other videos on youtube. sir plz, upload more and more videos of OS, we have exams.

[@shaheedashaikh9303]

Excellent..... students for proper understanding...plz add more videos regarding to deadlock

[@tsweetkorner]

sir har baar exam ya normally kucch samjha nahi aata I switch to ur channel thanku for delivering lecture in hindi

[@meet4509]

Sir,keep it up..you have wonderful way of teaching. please discuss more gate questions in your video...

[@KNOWLEDGEGATE_kg]

Hi Vishwameet, thank you so much for encouraging words,we will discuss more GATE questions in the upcoming videos. :)

[@abhijeetshukla4264]

What if we context switch a process after it exit while loop in wait() method and allow another process to start. Then two process will be in a critical section which is not what we want. Am i right or i am missing something?

[@shubhamrawat3635]

sir by these lectures , i am able to do question very easily.

[@KNOWLEDGEGATE_kg]

We are glad that we could be helpful :)

[@SUBRONEEL]

can you please upload videos on computer organization and computer networks. it would be a great help. and you are doing a great job .. the way you teach is very easy to understand. thanx a ton. 😀

[@apoorvashikarwar8248]

Doesn't look like this is mutually exclusive. Assume s = 1. Process P1 call wait(s), evaluates condition of while to false and then preempted before executing s = s -1 Now Process P2 call wait(s), evaluates condition of while to false, executes s = s -1 and goes to critical section and preempted P1 can resume execution from s = s-1 and land in critical section too. Hence, both the processes can access critical section together. Any explanations or something I might be missing here?

[@mohsin7343]

I also have the same doubt Did you got any answer for this How can semaphore achieve mutual exclusion?(according to the video, not possible)

[@karthik0999]

You have done a wonderful Job, requesting to give the presentation in English only , it would help the guys who dont know Hindi

[@akshitarawat1970]

Sir pehle algo bta diya karo as an example and saath saath explain kra kro plz. As jb semaphore ka concept beginner ke liye tough hota hai Like one process after execution gives a wake up system call to a process who is in sleeping state ,bt it couldn't see the call. When tht sleeping process wakes up ,it see no one there to give call ,go to sleep again. To solve this problem ,the first process who got executed puts the wake up call in the semaphore(a variable ),so tht whenever sleeping process wakes up,it ckecks the semaphore (as we do to see letter in post box)

[@suhailansari6947]

Short , Simple and precise Thankyou Sir

[@pulakkuli6173]

Best explanation I have seen for semaphores!

[@sanubd7795]

sir your video is audible only through one speaker or only through one side of earphone.

[@anurag9110]

आप बहुत ही बढ़िया शिक्षक हो

[@himani5436]

Kindly upload videos on Deadlock.....thnx...really all of ur videos are highly understandable

[@KNOWLEDGEGATE_kg]

Please checkout www.knowledgegate.in for full content!!

[@prayaglehana7187]

sir.. u are amazing.. u make our concepts so much clear... thanks 🙏