This channel is a blessing. During my undergrad, I used to refer to your videos to clear out my doubts. Now doing the same in my postgrad. Why on earth teachers can not teach like this.
@yajie7756
Жыл бұрын
Some teachers just try to talk for how long a lecture lasts...
@shreyanshgupta1587
Жыл бұрын
Capitalized Education 👍
@shamveerapan2875
10 ай бұрын
Cause they want to complete the portion.... they too want to make the students clear. ..but some can't because they dont know.. and many can't because they dont have much time.. they can give you only a outline...what to do???. Its out fate.. 😅😅😇😊😉
@abdelghanimoumen2524
Жыл бұрын
This perfect mini-course is better than my college's 10 hours course
@asmaaasmaa2395
Жыл бұрын
Hahahah yep ,it's useful for the cs students
@Lyricverse116
10 ай бұрын
True bro 😂
@bagos1997
3 жыл бұрын
If anyone is confused from the word Semaphore know that in Greek the word Σημαφόρος (Semaphoros) means Signal-bearer. Hope that helps.
@omardumet120
2 жыл бұрын
we call traffic lights "semaforos" in Spanish lol
@shivamxsingla
2 жыл бұрын
@@omardumet120 lol
@sasankv9919
2 жыл бұрын
Thanks, this opened up lot more meaning to this concept
@manuelconte2127
2 жыл бұрын
in italian "SEMAFORO"
@189Blake
Жыл бұрын
@@omardumet120 Yeah, my language is Spanish and when I heard the concept it was rather logical to know what it does
@nojoodothmanal-ghamdi1026
2 жыл бұрын
Thank you so much the idea is clear now, I cannot express how much you helped me
@tanish_mavi
Жыл бұрын
Best explaintion of semaphoros on the entire Internet. Thank you so much sir
@rupambiswas953
Жыл бұрын
Became a fan of this channel, it saved my degree 🙏🙏💙💙
@rohitkandula8493
11 ай бұрын
One an only king for Operating Systems🔥🔥🙏🙏
@himanshusoni1512
2 жыл бұрын
Djiktra himself explaining the Semaphore. Thanks
@dharanyuvi6951
2 жыл бұрын
Legendary explanation .., thank you champ
@surajbhardwaj1200
Жыл бұрын
Best explanation on KZitem.
@captureit4410
3 жыл бұрын
saviors for engineering students
@khangpiano549
2 жыл бұрын
Thank you
@divyasrisatyavada965
2 жыл бұрын
Wow what a explanation sir .I am very cleared about this topic after watching your video thank you so much for such a valuable information sir
@puneethj9920
3 жыл бұрын
Great video🙂
@darshil-oh2le
10 ай бұрын
Nicely Explained 👌👌
@coding_unicorn2
Жыл бұрын
Well explained 🧡
@nehasv7913
2 жыл бұрын
really awesome.
@aiqabusov6926
2 жыл бұрын
Great Content
@YuganNimsara
25 күн бұрын
was really helpful. thank you very much.
@DopetheKid
2 жыл бұрын
SIR YOU ARE GREAT
@avishkarkurkute4753
2 ай бұрын
neso, you are saviour🙌
@MatheusSilva-dragon
2 жыл бұрын
Damn! THANK YOU! You guys always help me!
@mriduljain6809
2 жыл бұрын
Amazing Explanation Sir.. Thank you so much 💓💓🥰🥰
@amanprajapati6301
7 ай бұрын
very valuable lacture for us thanks you 🤩
@himansushaw4938
2 жыл бұрын
very nicely explained. Thanks
@dnyaneshvarsalve2984
2 жыл бұрын
very good explanation
@eylulmood4830
2 жыл бұрын
why test and lock is a hardware solution? we also used a variable Lock, whereas semaphore is software solution
@patiencechiripanyanga7385
2 жыл бұрын
Well elaborated
@DonaldMurf
2 жыл бұрын
Thank you so much for this video.
@bakersisters7
Жыл бұрын
Best explanation ever🤌🤌
@ripudamansingh6928
2 жыл бұрын
sir you are the best
@iyadassaadnekka329
2 жыл бұрын
Very very amazing thank you
@muhammadmaawaz1221
8 ай бұрын
Thanks
@shifankphoulad
2 жыл бұрын
Nice 😊☺️👍👍
@sriharika4573
Жыл бұрын
What problem is there in critical section problem?
@nilou-s8l
Жыл бұрын
Are sem_signal and sem_post the same thing? I’m a bit confused
@decostarkumar2562
2 жыл бұрын
It's wrong. In semaphore loops are not present. To avoid busy waiting symbols are used .
@mughatoamugha9029
3 жыл бұрын
🙂 hi.. holaaa... Good to be here again 😇
@minidupasan1520
2 жыл бұрын
@anirudh7137
2 жыл бұрын
I have a doubt. Let's say I am using s=1 and have 4 threads(t1,t2,t3,t4) that I want to allow in the critical section one by one. Now let's say t1 is scheduled first and it passes the while condition. But what if at this very moment(i.e before t1 can do s--) context is switched and t2 now checks while condition and also passes through. Now, we have two threads t1 and t2 that can enter the critical section which we don't want. Isn't this a problem? The only way it would work is if entire wait() can be atomic. But i don't think any language supports atomic blocks or functions.
@AMITKUMAR-dj2fv
Жыл бұрын
In the beginning of the video, sir told that both wait and signal is an atomic operations.
@huhhzy
9 ай бұрын
👍
@01.abhishekkumar33
2 жыл бұрын
I am your big fan joshy sir ,you are my hero sir ,can you please give your no sir
@jiangzhenni741
11 ай бұрын
you are my daddy from now on
@Mrsarchanaharish
Жыл бұрын
S-- can never happen if S is already 0. If P1 set S to 0. If P2 did P(), it will be stuck in loop forever and can never make S as -1. The code belongs to binary semaphore and not true for counting semaphore that can take negative values. The code in P() should be while(S==0) instead.
@hey_sree
Жыл бұрын
have been thinking about this for an hour now. just realized he said the initial value of S is assumed 1.
@diassaiynov8360
Жыл бұрын
too much unnecessary information
@aun5252
4 ай бұрын
Just skip that man he clears all misunderstandings if anyone has. You should thank him for teaching freely
@cit0110
2 ай бұрын
@@aun5252100%
@karamvirsinghbatra9646
11 ай бұрын
mera naam puss hai
@huyvole9724
3 жыл бұрын
bad, you need animation or history, ... something like that. Don't talk so much
@alrabbi6194
2 жыл бұрын
Then what are the subtitles added for ?
@kavyabanka4482
3 жыл бұрын
Please send memory management in you tube not only in neso fuel please release in u tube
@elmass3662
3 жыл бұрын
NESO academy really be pulling through. Thank you so much sir!
@klaik30
2 жыл бұрын
The point of mutex is to lock a critical section so that it is thread safe but the call for P() itself is not, right? If two processes each read the check for S they will both see that S > 0 and continue to both run S--. How is this accounted for? I dont think the video talked about this specific scenario?
@hetaeramancer
3 жыл бұрын
Wow a new video on OS, finally I can continue my learning on OS that has begun since 2018 LOL
@invinciblegirl4386
2 жыл бұрын
😂😂
@AbhishekGupta-vu7zt
2 жыл бұрын
😂😂
@NandhiniG-h6o
8 ай бұрын
So u took 3 years to learn os huh
@ShainaSandhu
5 ай бұрын
@@invinciblegirl4386😊😊
@ShainaSandhu
5 ай бұрын
@@invinciblegirl4386😊😊😊😊😊
@ashishchawla9035
2 жыл бұрын
But as the critical section can only be accessed by one process at a time so how two processes are entering the critical section at the same time and using it in counting semaphore?
@ahmedrateb5867
5 ай бұрын
Counting semaphores are a generalisation of binary semaphores, whereas binary allows a maximum of 1 process to enter the critical section, counting allows up to n where n is a positive integer
@SOWProgramming
4 ай бұрын
Counting semaphores are used when processes need to access a resource which has n instances, so N processes can access that resource.
@alokendughosh7013
2 жыл бұрын
This presentation is too good. Understood it perfectly. Thank you so much sir❣️
@eswarpethraj9099
3 жыл бұрын
In counting semaphores, if S is set to 4, then 4 processes enter the critical section at the same point of time, how it's possible because only one process can access the critical section. And what do you mean by an instance of a resource? Any example with c++ 20 code using counting semaphores.
@subbumotepalli
3 жыл бұрын
Same doubt .if you know plz explain
@apurvkumar1808
2 жыл бұрын
S is set to 4 means there are 4 instances of the resource so 4 processes can enter in critical section at once.
@wasalawyer.1179
3 ай бұрын
does that violate Mutual Exclusion principle?@@apurvkumar1808
@MrAmalthejus
3 жыл бұрын
How can a Resource have multiple instances?! What kind of Resources are you talking about?
@Makerelax444
16 күн бұрын
IN COUNTING SEMAPHORE : Two processes goes to critical section at same time then it disobey mutual exclusion. How it is a solution
@Account-fi1cu
2 жыл бұрын
Thank you!
@abrargadelrab8093
2 жыл бұрын
well explained.
@balaganeshn4442
2 жыл бұрын
Thanks a lot for your clear explanation , Is there any video for MUTUX?
@fahedzidani2681
2 жыл бұрын
instead of using var S u use mutex
@Nilotpal_Chakravarty_
2 жыл бұрын
Mutex locks are basically binary semaphores
@mihneapostoaca5044
2 жыл бұрын
You are a master,sir!Great job!
@venkataswamykadiyam977
3 жыл бұрын
Sir, please upload remaining videos in youtube. We can't be able to take screenshots of the lectures in neso app to revise them whenever we want...
@Lawleit_L
11 ай бұрын
But what is the different between locks / semaphores and the other algorithms that we have seen like FCFS, RR and SJF , because all of them are synchronize and arrange the prosses.
@Bearded_Dragon_Sir
2 жыл бұрын
Thanks!
@kerematasen399
2 жыл бұрын
Best explanation ever.
@medhananjay9099
3 жыл бұрын
what an amazing explanation thankyou so much neso academy it is very heplfull !! thankyou again
@fullstackcourse
5 ай бұрын
You're the best!!
@nguyeninhan8542
11 ай бұрын
this is absolutely better than my university's course
@MiniduPunsara
6 ай бұрын
always the best
@tanzimhasan4464
3 жыл бұрын
Thanks for this valuable video 💗
@vinayak186f3
3 жыл бұрын
Why is there no while loop in signal's def. i mean if it's a binary semaphore and is already 1 won't it overflow ?
@diptabose7187
3 жыл бұрын
S never exceeds one in binary semaphore , because to access the critical section wait operation is done. And after accessing signal operation is used . As signal and wait operations are used indivisibly , Semaphore value doesn't overflow , it remains between 0 and 1.
@HabibiTau
22 сағат бұрын
Best way to cover syllabus in less time is to watch your videos.
@bhuvaneshwarig6517
2 жыл бұрын
So tough:(
@ahmedrateb5867
5 ай бұрын
Outstanding, makes it so easy and the way it s presented is great
@chhajedji
2 ай бұрын
What if s=1, hence both P and V execute simultaneously and during s++ and s-- we face the original producer consumer problem and instead of s being 1, takes value 0 or 2?
@zero4one-A13
5 күн бұрын
I'm watching this video for tomorrow my os exam lol
@mohammadadrees5263
2 жыл бұрын
Thank you sir. explained very well.
@bishnubhusal5999
2 жыл бұрын
All the videos are great, only the lacking thing is coding part.
@samarthtandale9121
Жыл бұрын
To prevent/protect a shared resource from being accessed by multiple processes at the same time we use Semaphore S, and wait() and signal() operations. But for wait() and signal(), again, the Semaphore is shared resource and they have critical section in them, so we have to again implement mutex for Semaphore S and so on. So, If you got what I just said, to solve a problem of mutex, we are generating another problem of mutex and that will recursively generate another and so on... So how do you solve this problem or where exactly did I go wrong?
@Mehraj_IITKGP
Жыл бұрын
You are correct that using a semaphore to protect a shared resource can introduce its own synchronization issues, particularly if multiple threads or processes need to access the semaphore itself. This can lead to a problem known as "semaphore contention," where threads or processes contend for the semaphore itself, rather than the shared resource it is protecting. To address this issue, it is important to carefully design the critical sections for the semaphore and ensure that they are as small and simple as possible. In particular, the critical section for the semaphore should be limited to the code that directly modifies the semaphore's value, such as the wait() and signal() operations. One common approach to minimizing semaphore contention is to use a variant of the semaphore known as a "spinlock." A spinlock is a type of lock that repeatedly checks the value of the semaphore in a loop until it becomes available, rather than blocking the thread or process. This can reduce the overhead of context switching and thread synchronization, particularly in high-concurrency environments. Another approach to reducing semaphore contention is to use techniques such as "reader-writer locks" or "lock-free algorithms," which are designed to allow multiple threads or processes to access a shared resource in a more fine-grained and efficient manner, without relying on traditional locks or semaphores.
@samarthtandale9121
Жыл бұрын
@@Mehraj_IITKGP Thank You very much for taking time to resolve my doubt !!!
@samratpatel8060
Жыл бұрын
@@Mehraj_IITKGP wow , wrote an long ass para for solving a strangers doubt
@lowerbound4803
3 жыл бұрын
How could we ensure that S will never be altered from different sources simultaneously?
@raaj7256
2 жыл бұрын
It's because they're atomic. I guess they're internally atomized using test_and_set or compare_and_set, and my faculty told test_and_set and compare_and_set cannot be called at the same time, there for you can't really call them at the same time (Don't know if the "cannot be altered part" is correct though).
@lowerbound4803
2 жыл бұрын
@@raaj7256 Thank you for your answer!! I have to learn how atomic works.
@harshmishra9008
2 ай бұрын
Is there any platform to get the notes of the lectures?
@farahmohamed2104
10 ай бұрын
The session is too good. and precise Helps to understand very clearly. Thank you
@wizardop2100
Жыл бұрын
very well explained sir.Thank you so much
@huhhzy
9 ай бұрын
i really appreciate you
@abdi.
2 жыл бұрын
thx dawg, gotta exam this morning. this really helped
@adilmughal2251
Жыл бұрын
one of the best explanation.
@goldenarmer6363
Жыл бұрын
God level explanation💥👌
@ngk442
Ай бұрын
Great explanation ❤
@theomniking7856
Жыл бұрын
ive learnt more things from neso academy (and other youtube tutorials ) than in UNI
@wasalawyer.1179
3 ай бұрын
And it is no joke
@jaikishank
Жыл бұрын
Excellent and crisp explanation. Thank you.
@aboudejeber1976
2 жыл бұрын
Thank you sir , that's the explanation i was looking for 🌹
@MrMaschine999
9 ай бұрын
Why is it possible for different processes to be in the critical section for counting semaphores? I thought you sad we only want one process at a time in the critical section. Did I misunderstood something?
@akarshta8087
8 ай бұрын
good
@somethingnew3654
2 жыл бұрын
In counting semephore..mutual exclusion is not followed..then how is it solving critical section problem?
@manoharacharyasakec
4 ай бұрын
7:21
@nashrahsultan123
Жыл бұрын
please make me understand why S-- is there pleaseeeeeeeeeeeeeeeeee
@amillion7582
2 жыл бұрын
damn, my professor literally took months to explain this simple concept
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