Ir ao conteúdo

Exercicio 1 – Sistemas Operacionais II – INE5424 – UFSC

Trabalho 1 – EPOS
Idle-waiting Thread Joining
– Este trabalho tinha como objetivo alterar o modo que era feito o “join” em uma Thread. Sendo que o mesmo inicialmente era feito da seguinte maneira:
[code lang=”c”] while(_state != FINISHING)
yield();
[/code]

O mesmo consiste basicamente, em verificar o estado da thread que se esta dando join e caso o estado nao seja FINISHING dar a vez a outro processo. Esta solucao, acarreta no consumo excessivo de recursos ja que o mesmo sempre retorna para a fila de _ready. E eh executado novamente quando o escalonador escolher esta thread. O trabalho pede que seja modificado de modo que o consumo de recursos nao seja excessivo.

Arquivos Modificados:
thread.cc
Thread.h

Solucao:
     Foi criada uma variável adicional em threads.h, _waiting_for_me, que é um ponteiro para uma thread. Quando o método “join” é chamado, a thread que está executando é colocada no _waiting_for_me da thread chamada e é suspensa. Se a thread já finalizou ou alguém já chamou “join” nela, nada é feito. No método “exit”, caso _waiting_for_me esteja preenchida, é chamado o método “resume” na thread referenciada.
     Pensamos em colocar uma lista de referências para várias threads poderem dar “join” na mesma thread, porém vimos na documentação do POSIX que isso era considerado um erro lógico, e achamos que acarretaria um consumo de recursos adicional desnecessário, pois não seria possível usar o _link já existente na thread, já que ela teria de estar tanto na lista de suspensos quanto na lista _waiting_for_me da outra thread.

Explicacao mais detalhada da implementacao escolhida e outras solucoes pensadas.

8.893 Comentários

  1. I’ve got the scars to prove it, the rental landscape down here is crazy. Then you show up at the local lot to pick up the car. Different car waiting — scratches everywhere, smells like an ashtray, and that “amazing price”? Doesn’t include the mandatory $400 cleaning fee or the $30 per day toll pass you can’t waive. Fool me eight times? That’s just another Tuesday in the 305, lesson learned. If you are trying to find a legitimate luxury fleet without getting ripped off, run far from the airport counters. Anyone who’s waited for an Uber in August understands exactly what I mean about this city, whether you are doing South of Fifth brunch, Design District shopping, or a spontaneous Keys trip.

    I’ve run through maybe 45 rental companies across Dade, Broward, and Monroe, but I eventually found a service where what you book is exactly what shows up, no surprises, no fine print nightmares. If you are looking for the only honest source for premium wheels across South Florida, check the current details here: rent cadillac escalade near me rent cadillac escalade near me. Yeah, parking in South Beach will cost you a nice bottle of wine — but that’s the Miami tax. Just drive safe out there and absolutely skip that “windshield protection” upsell — pure profit for them, zero value for you. hope this helps some of you save a few bucks.

  2. Reading this prompted a small note in my reference file, and a stop at canyoncovecommerceatelier prompted another, the rare site that contributes useful nuggets to my own working knowledge rather than just consuming my attention is worth the time investment many times over compared to the usual pile of forgettable scroll content.

  3. Really like that the writer trusts the reader to follow simple logic without restating every previous point, and a stop at skyharborcommercegallery kept that respect going, treating an audience as capable adults rather than as people who need constant hand holding makes a noticeable difference in the reading experience for me.

  4. Found this through a search that was generic enough I did not expect quality results, and a look at brightharborvendorhall continued the surprisingly good experience, search engines occasionally still surface excellent independent content if you scroll past the obvious paid and high authority results which is reassuring to remember sometimes.

  5. Bookmark earned and shared the link with one specific person who would care, and a look at coralbrooktradingfoundry got the same targeted share, sharing carefully rather than broadcasting is a discipline I try to maintain and this site is generating shares from me at a sustainable rate rather than the spam rate of viral content.

  6. Useful information presented in a way that does not feel like a sales pitch, that is what I appreciated most, and a stop at skyharborcommercegallery was the same, no upsell and no fake urgency just steady content laid out properly for someone trying to actually learn from it rather than just be sold to.

  7. Let me save you some serious time, learned this the hard way. You see a sweet ride online — clean spec, fair price, looks legit. Different car, scratches all over, and that “all-inclusive” price? Yeah that didn’t include insurance, fees, or the mandatory cleaning charge. I’ve lived here for years and still get burned occasionally. When you’re after a trustworthy and reliable premium vehicle to cruise around, don’t just grab the cheapest option on Kayak. Ask anyone who’s tried Ubering across the 305 during rush hour, especially since the AC must freeze your teeth and you want unlimited miles or bust.

    Most of these local agencies are just smoke and mirrors with decent SEO hiding overpriced junk, until I finally found one outfit that actually delivers what’s in the listing. If you are looking for the only honest broker for premium vehicles across South Florida, check the current availability here: car rental near miami beach https://luxury-car-rental-miami-5.com. Yeah, finding parking in Wynwood will test your patience — but that’s not on them. Just drive safe out there and maybe decline that “premium roadside” upsell — it’s always a scam. let me know if you guys have any other clean spots.

  8. Reading this triggered a small reorganisation of my own thinking on the topic, and a stop at discovernewfocus furthered that reorganisation, content that affects the shape of my mental model rather than just decorating it with new facts is content with structural rather than informational impact and this site provides that.

  9. Let me save you some serious time, learned this the hard way. Miami rental game is wild — half these local clowns show you a custom Mercedes online and hand you a busted sedan with mismatched tires. You land at MIA, tired, grab an Uber to the rental office, and bam — surprise $1500 hold on your card. Fool me four times? Not happening, lesson learned. When you genuinely need a proper and reliable premium ride to cruise around, skip the airport counters entirely. Miami without a decent whip is basically a punishment, especially since the AC must be ice cold and you want zero mileage games.

    I’ve personally tested maybe 25 rental outfits across Dade and Broward, until I finally stumbled on one provider that doesn’t play games. If you are looking for the only straight-up source for premium wheels in South Florida, check the current details here: rental cars near miami beach rental cars near miami beach. Also, definitely bring polarized shades unless you enjoy driving completely blind into the sunset. Anyway, at least there’s one honest rental joint left in this town, let me know if you guys have any other clean spots.

  10. Will be back, that is the simplest way to say it, and a quick visit to goldencoveartisanexchange reinforced the decision, this site has earned a spot in my regular rotation alongside a few other reliable places I check when I want something genuinely informative without all the usual modern web noise getting in the way.

  11. Closed the tab and immediately reopened it ten minutes later because I wanted to reread a part, and a stop at kettleharbormarkethouse drew the same return, content that pulls you back after closing it is doing something well beyond the average and worth marking as exceptional in my mental catalogue of reliable sites.

  12. Glad I gave this a chance rather than scrolling past, and a stop at brightharborvendorhall confirmed I made the right call, sometimes the best content is hidden behind unassuming headlines that do not scream for attention and learning to slow down and check those out has paid off many times now across years of reading.

  13. Picked this for my morning read because the topic seemed worth the time, and a look at woodharborcommercegallery confirmed the choice was right, my morning reading slot is precious and giving it to this site felt like a good investment rather than a waste which is a higher endorsement than I usually offer for content.

  14. Reading this slowly in the morning before opening email, and a stop at quickridgemarketgallery extended that protected attention, content that earns the prime morning reading slot before the daily distractions begin is content with elevated status and this site has earned that prime slot consistently in my recent reading habits clearly.

  15. A quiet piece that did not try to compete on volume, and a look at embermeadowmarketguild maintained that selective approach, sites that publish less but better are increasingly rare in an environment that rewards volume and this one has clearly chosen quality cadence over quantity which is a brave editorial decision in current conditions.

  16. Now placing this in the same category as a few other sites I have come to trust, and a look at wildorchardartisanexchange continued the placement decision, the small category of fully trusted sites is one I extend rarely and only after multiple positive reading sessions and this site has earned the category placement methodically over time.

  17. Now feeling slightly more optimistic about the state of independent writing online, and a stop at kettleharbormarkethouse extended that quiet optimism, sites like this one are the reason I have not given up on the open web entirely and finding them occasionally renews the case for paying attention to non algorithmic content sources today.

  18. Worth saying that the quiet confidence of the writing is what landed first, and a look at discovernewfocus continued that quiet quality, confident writing without the loud display of confidence is a rare combination and this site has clearly developed both the knowledge and the editorial restraint to land that combination consistently.

  19. Bookmarked the page and the homepage too because clearly there is more to explore here, and a quick stop at linenmeadowmarkethall only made that more obvious, this is the kind of place I want to dig through over a weekend rather than rushing through during a coffee break tomorrow morning before getting back to work.

  20. Walked away in a slightly better mood than when I started reading, that says something about the writing, and a stop at caramelcovecraftcollective kept that going, content that leaves you feeling more capable rather than overwhelmed is the kind I keep coming back to again and again over the years and across many topics.

  21. Been burned enough times to write a book on this nonsense. Then you actually go to the local office to pick it up. Completely different car waiting for you, check engine light on, and that “low rate”? Doesn’t include the mandatory insurance they somehow forgot to mention. Seven years in South Florida and I still almost fall for these tricks. If you are trying to find a legitimate luxury fleet without getting ripped off, avoid the airport like the plague. Anyone who’s taken the Metro here knows the struggle about this city, especially since the AC must freeze your face off and unlimited miles or forget it.

    I’ve tried maybe 40 rental companies across Dade, Broward, and Palm Beach, but I eventually found a service with no games, no bait-and-switch, and no hidden asterisks in paragraph 8. If you are looking for the only straight shooter for premium rides across South Florida, check the current details here: luxury car rental agency luxury car rental agency. Yeah, parking in Brickell will cost you a nice steak dinner — but that’s just Miami life. Anyway, glad there’s at least one honest rental joint left in this town, let me know if you guys have any other clean spots.

  22. Glad the writer did not feel compelled to cover every possible angle of the topic, focus is a virtue, and a stop at woodharborcommercegallery reflected the same disciplined scope, knowing what to leave out is half of what makes good writing good and this post has clearly been edited with that principle in mind.

  23. Decided to read more before commenting and the more I read the more I wanted to say something, and a stop at bravofarms pushed that impulse further, when content provokes the urge to participate rather than just consume it is doing something quite specific and worth recognising clearly when it happens during reading.

  24. Now wishing I had found this site sooner, and a look at caramelcovecommerceatelier extended that mild regret, the calculation of how many years of good content I missed by not finding the right sources earlier is one I try not to make too often but it does come up sometimes when I find sites this good.

  25. Refreshing to find writing that does not try to manipulate the reader into clicking onto the next page through cliffhangers and forced engagement, and a stop at dazzquays continued in the same respectful way, this is what reader first design actually looks like in practice rather than just in marketing copy that sounds nice.

  26. Felt like the writer was speaking directly to someone with my level of curiosity, neither talking down nor showing off, and a stop at dawnbrookmarketfoundry kept that comfortable matching going, finding writing that meets you where you are rather than asking you to climb up or stoop down feels great every time it happens.

  27. Now recognising the specific pleasure of reading writing that shows real care for sentence shapes, and a look at cottongrovegoodsgallery extended that craft pleasure, sentence level writing quality is something most blog content ignores entirely and this site has clearly invested in the prose layer alongside the substance which is rare today.

  28. Skipped the comments section but might come back to read it, and a stop at suncovecraftcollective hinted at a quality reader community, sites where the comments are worth reading separately from the post are increasingly rare and signal a particular kind of audience that has grown around the editorial vision over time gradually.

  29. Now planning to come back when I have the right kind of attention to read carefully, and a stop at embercovecommerceatelier reinforced that plan, choosing the right moment to read certain content is a quiet form of respect for the work and this site is generating those careful planning behaviours from me consistently as a reader.

  30. Thanks for putting in the work to make this approachable, plenty of sites cover the same ground but most do it badly, and a quick visit to nextgenbuyhub confirmed this one stands apart, simple language and useful examples without anyone trying to sell me anything along the way which I really appreciated.

  31. Found a small mental shift after reading this, the framing here is just a bit different from the standard takes online, and a look at marbleharbortradehall extended that fresh perspective across more material, the rare site whose voice actually changes how you think about something rather than just confirming existing beliefs.

  32. Will share this on a forum I am part of where it will be appreciated by others working in the same area, and a look at cottonmeadowcraftcollective suggests there is more here worth passing along too, definitely a generous resource that deserves a wider audience than it probably has today across the open internet.

  33. Thanks for sharing this with the open internet rather than locking it behind a paywall like so many sites do now, and a stop at konvexa kept the same vibe going, generous helpful and clearly written by someone who actually wants people to learn from it rather than just charge them.

  34. Reading this in the morning set a good tone for the day, and a quick visit to gemcoast kept that good tone going, content can do that sometimes when it hits the right notes and finding sites that consistently strike that tone is something I have learned to recognise and reward with regular visits.

  35. A piece that did not lean on the writer credentials or institutional backing, and a look at dawnbrookmarketfoundry maintained the same focus on substance, content that earns trust through quality rather than through name dropping is the kind I find most persuasive and this site is clearly playing on the substance side of that distinction.

  36. Good quality through and through, no rough edges and no signs of being rushed, and a quick look at cottonbrookvendorfoundry kept the same polish going, the kind of site that respects its own brand by maintaining consistency across pages which is something I always appreciate as a reader looking for trustworthy information online today.

  37. Reading this on a difficult day was a small bright spot, and a stop at clovercrestmarketparlor extended that brightness, content that improves a hard day is content that has earned a particular kind of place in my reading habits and this site is occupying that uplifting role for me today which I appreciate clearly.

  38. The examples really helped me grasp the points faster than abstract descriptions would have, and a stop at marbleharbortradehall added a few more practical illustrations that drove the message home, the kind of writing that knows its readers learn better through concrete situations rather than vague generalities is rare and worth recognising clearly.

  39. Just want to say thank you for putting this together, posts like these make searching online actually worth it sometimes, and a quick look at globalgoodscenter kept that going, useful and easy to read without any of the tricks that ruin most blog comment sections lately on the wider open web.

  40. Polished and informative without feeling overproduced, that is the sweet spot, and a look at embercovecommerceatelier hit it again, you can tell when a site has been built with care versus thrown together for the sake of having something to put online and this is clearly the former approach taken by the team.

  41. Let me save you some serious time, learned this the hard way. You see this gorgeous deal online — clean spec, fair price, looks like a dream. Completely different car sitting there — dents everywhere, smells like cheap air freshener covering something worse, and that “dream price”? Doesn’t include the mandatory $50 daily insurance or the $300 “administrative fee” they invent at checkout. Fool me eleven times? That’s just called living in Miami, lesson learned. When you’re searching for a legit and reliable premium ride to cruise around, do some real digging first and read actual customer reviews. Anyone who’s tried the bus here knows exactly what I mean about this city, whether you are doing Key Biscayne sunset, Design District shopping, or a spontaneous drive down to the Everglades.

    I’ve tested maybe 60 rental companies across Dade, Broward, and Collier, but I eventually found a service with no games, no switch, and no hidden BS in paragraph 12 of the contract. If you are looking for the only honest source for premium rides across South Florida, check the current details here: opf luxury car rental opf luxury car rental. Yeah, parking in South Beach will cost you a nice bottle of champagne — but that’s the Miami tax. Anyway, glad there’s at least one straight operator left in this rental jungle, let me know if you guys have any other clean spots.

  42. A piece that handled a controversial angle without becoming heated, and a look at garnetbrookvendorfoundry continued that calm engagement, content that can address contested topics without inflaming them is doing rare diplomatic work and this site has clearly developed the editorial maturity to handle sensitive material with the appropriate temperature of writing throughout.

  43. Worth a quiet moment of recognition for the consistency I have noticed across multiple posts, and a stop at nightorchardtradeparlor continued that consistent quality, sites that maintain quality across many pieces rather than peaking on one viral post are sites with real editorial discipline and this one has clearly developed that discipline carefully.

  44. Refreshing to find writing that does not try to manipulate the reader into clicking onto the next page through cliffhangers and forced engagement, and a stop at floraharborvendorhall continued in the same respectful way, this is what reader first design actually looks like in practice rather than just in marketing copy that sounds nice.

  45. My time on this site has now extended past what I had budgeted, and a stop at emberstonevendorlounge keeps extending it further, content that overstays its budget in my schedule is content that has earned the extra time and this site has been earning extra time across multiple visits to the point where my schedule needs adjustment.

  46. Знаете, ситуация — человек в запое , а куда бежать — просто руки опускаются. Я сам через это прошел пару лет назад . Сначала кажется, что обойдется , но хрен там. Нужна реальная медицина. Перерыл весь интернет — только деньги тянут. А потом наткнулся на один нормальный вариант. Если ищешь где получить наркологическая помощь — не ведись на дешевые акции . У нас в Воронеже, если честно, хватает левых контор без лицензии. Вся проверенная информация ниже по ссылке: анонимное лечение алкоголиков https://narkologicheskaya-pomoshh-voronezh-12.ru Честно скажу , после того как прочитал , понял свои ошибки. Там и про вывод из запоя , и про реабилитацию . Плюс работают круглосуточно — это важно . Рекомендую не тянуть .

  47. Better than the average post on this subject by some distance, and a look at etherfairs reinforced that, you can tell within the first paragraph that the writer here actually cares about the topic rather than just covering it for the sake of having something to publish that week or that day.

  48. Alright listen up because I’m about to save you a massive headache. Then you actually show up to the local office to pick up the car. Plus they freeze a surprise $4500 on your card and say “don’t worry, it’ll drop off in a week or two” right before giving you the keys. Twelve years in South Florida and these jokers still almost catch me sleeping. When you need a proper and reliable premium ride to cruise around, do some real digging first and read actual customer reviews. Miami without real wheels is basically a nightmare, especially since the AC must be ice cold and unlimited miles non-negotiable.

    Most of these local agencies are just shiny turds with fake five-star reviews bought in bulk online hiding overpriced junk, but I eventually found a service where what you book is exactly what shows up, no surprises, no hidden fine print. If you are looking for the only straight shooter for premium rides across South Florida, check the current details here: rent luxury sedan miami rent luxury sedan miami. Yeah, parking in Brickell will cost you a nice dinner — but that’s the price of paradise. Just drive safe out there and absolutely skip that “windshield protection” upsell — complete waste of money. hope this helps some of you save a few bucks.

  49. Considered against the flood of similar content this one stands apart in important ways, and a stop at createforwarddirection extended that distinctive feel, sites that find their own corner of a crowded topic and stay there are sites worth following and this one has clearly carved out its own space and committed to defending it carefully.

  50. Just one of those reads that left me feeling slightly more capable rather than overwhelmed, and a look at ferncovecommerceatelier kept that empowering feel going, the difference between content that builds the reader up and content that intimidates them is huge and this site clearly knows which side of that line to stand.

Deixe um comentário

O seu endereço de e-mail não será publicado. Campos obrigatórios são marcados com *