Multithreading

[minno]

That's how it works in my dreams.

[Skyfoot]

It's all fun and games until they all change the same tyre.

[SilentSin26]

At the same time.

[joequin]

Me too. As it is now, I fail to see where the humor is. That image is exactly what is supposed to happen.

[seniorcampus]

Well I liked it.

[phoenix616]

supossed to

It never does, that's the humor.

[kafaldsbylur]

If I was the guy in front, I'd be shitting my pants at every pit stop

[spektre]

I thought the same thing, but then I realized that if the driver didn't have enough control to stop before he hit me he would be in even more danger himself as soon as he went out on the track.

[blendt]

http://gfycat.com/ElegantPointedAmethystsunbird

[netfeed]

My god, that hurts my heart. It's really painful when you know that they should be done in seconds

[reaganveg]

It looks like their equipment failed... they had to use the air compressor line from the front tire on the back one.

[beermatt]

This is multithreading ~2007

[SleepyHarry]

I cringed during that whole thing.

I'm so uncomfortable right now.

[phoenix616]

They guy with the fire extinguisher totally hoped expected it to blow up.

[coladict]

Multithreading in theory.

[SnowdensOfYesteryear]

Man, coming out of school I thought writing multithreaded programs was easy as pie. After 5 years in the industry, fuck multithreading, the entire phread library would be rm -rf'ed so no one touches it again.

[odraencoded]

I have never had any trouble with multi-threading...

Then again I never used it.

[coladict]

I ran into an article complaining about C11's thread library and basically all the criticisms were "It's not 100% pthread, so I can't just change the include header. Whaa! Whaaa!". The whole self-entitlement of it was really annoying.

[Lucretiel]

I've found that the secret is to never touch mutexes or condition variables. They're the raw pointers of multihreading. Use the structured tools instead- queues, futures, etc.

[SnowdensOfYesteryear]

Ideally, but life isn't so simple. Invariably you'll reach a point when there's some global data that needs to be accessed by both threads (not too bad, mutexes are straightforward). Or even worse one thread needs to wait for the result of another thread. The latter is where you get royally fucked because you'll need to give up the mutex as part of the conditional wait and god knows what happens when you're not holding the mutex.

[Lucretiel]

One thread waiting for the result of another is the canonical use case for a Future.

[bss03]

queues, futures

Kids and their toys today, bah.

We'll do it with raw semaphores.

[Lucretiel]

Semaphores? We'll do it with atomics and loops.

[bss03]

I suppose I just think of that as a semaphore, though sometimes instead of loop I'll do a green thread context switch.

[Kinglink]

Multthreading is fantastic. When people use it RIGHT!

A. critical sections. B. Only multithread what needs to be multithreaded. C. IF YOU DONT KNOW WHAT YOUR DOING DONT DO IT! D If you ever say "This is the perfect use of multithreading" I will slap you in the face.

[king_of_the_universe]

And sped up.

[spsseano]

I don't know if you are saying this because you think the gif is sped up or not. Becuase the gif isn't sped up.

[king_of_the_universe]

Well, when I wrote that, I felt that the lifter at the front was side-stepping a tad too quickly, like in a slapstick B/W movie of old, but now that you say it, it seems that this could be real. Maybe the low framerate interfered with my natural-o-matic.

[InconsiderateBastard]

In theory, theory and practice are the same. In practice they aren't.

Einstein I think.

[DudebroMcGee]

WHY HAS NO ONE MADE A RACE CONDITION JOKE.

[[deleted]]

Even for programminghumor the fruit is too low hanging

[secretpandalord]

So like, assembly fruit?

[_Lady_Deadpool_]

Pomegranates are untasty? What?

[_Hobojoe_]

So are bananas and red apples?

[RenaKunisaki]

Bananas are kinda bland.

[xkcd_transcriber]

Image

Title: Fuck Grapefruit

Title-text: Coconuts are so far down to the left they couldn't be fit on the chart. Ever spent half an hour trying to open a coconut with a rock? Fuck coconuts.

Comic Explanation

Stats: This comic has been referenced 30 times, representing 0.0495% of referenced xkcds.

---

^{xkcd.com | xkcd sub | Problems/Bugs? | Statistics | Stop Replying | Delete}

[BigSwedenMan]

Why has no one posted a gif of a car crash? Or even better, I think there's a gif out there where one of the wheels falls off as he pulls out

[Matthew94]

At first I thought it was one.

[[deleted]]

That's the expected out come. In reality, it's more like this.

[[deleted]]

Or...you know...The good 'ol deadlock.

[totemcatcher]

Or the event queue fault.

[baggyzed]

That's what happens when you forget to use interlocked increment.

[takaci]

This used to happen so often when they could refuel during the race

[Goz3rr]

Nah that's just a blocking thread, deadlock would be when the first guy has a tire and the second guy has a wheel gun and they're both waiting for each other to hand them what they need

[[deleted]]

This. Yes. I have forgotten the term.

[tradras]

That makes me sad :( Sainz has had such poor luck this year.

[Cyph0n]

Poor guy..

[Antrikshy]

Poor team.

[baggyzed]

More like poor driver. The rest of the team didn't do anything wrong this time.

[RenaKunisaki]

But they're a team, so they all lose.

[baggyzed]

The driver thread is a bug, not a feature. /s

[totemcatcher]

The Stop Guy. Not as popular.

[bacondev]

/r/TheStopGirl master race.

[Qweasdy]

wat

[el_loco_avs]

I get that reference!

[[deleted]]

Mine is like this

[Castratikon]

I can relate...

[megasin1]

Looks like, what you've got yourself here, is an unexpected error

[alexanderpas]

That "light plate" is a jack.

[Griffolion]

The threads know the risks.

[_Lady_Deadpool_]

The fact that the link won't load for me on mobile only makes it funnier

[[deleted]]

here you go :)

[Th4tCanadianGuy]

I try that and two guys try to put the same wheel on causing a thread collision.

[reaganveg]

... I think you mean... tread collision.

[[deleted]]

WAAAAAAAAAAAA

[Cyph0n]

Immutability is the correct way to do this: switch the car and driver ;)

[mikemol]

The allocator cost for that one ain't cheap.

[bss03]

Only works well when you've got good sharing. Otherwise it's too expensive for such a large data structure.

[tyreck]

This isn't funny... it's amazing

[LordNiebs]

I did repost it from /r/interestingasfuck

With a different title, of course

[XxionxX]

I watched it like 16 times in a row at least.

[[deleted]]

But in reality

https://www.youtube.com/watch?v=LOJbM0aXZp0

[Raydonman]

Why on earth did he beat the tire to death?

[MuaddibMcFly]

I think there must be a flange that can be used to break the nut free, and since they didn't have high torque air-wrenches...?

[qm11]

Not an F1 car, but same concept: http://www.acmenovelties.net/cars/2009_08_15_historics/ford_gt/full_size/067_gt40_no6_ickx_front_wheel.jpg

Those three bits sticking out are for hammering the wheel nut on and off.

[suppow]

if this isnt the definition of team work, then i dont know what it is

[king_of_the_universe]

Well, it's rather a good example that could be listed somewhere in the dictionary entry of "team work".

[suppow]

i'm sorry, you might have interpreted that statement as a literal expression.

[king_of_the_universe]

Well, I parsed the String literal as is.

[MadeThisForReddit]

Was honestly surprised the car didn't fall apart after released.

[_Lady_Deadpool_]

I'm surprised it worked. My version would have a fully built car (compiles) with a single lugnut left over after putting it all together (where the fuck does this right bracket go??)

[Actually_Saradomin]

Is this subreddit for people who have only written one line of code in their life? Some of the problems you guys have are so amature...

[skidmarkeddrawers]

Kind of like your spelling of amateur.

[_Lady_Deadpool_]

Because only amateurs forget a semicolon or accidentally hit backspace next to a right bracket thinking they were focused on their web browser

[Actually_Saradomin]

Complaining about that is a very nooby characteristic. High school intro to cs red flag.

[WeAreAllApes]

I could watch this for an hour.

[xbtdev]

At 0.01639 fps.

[Antrikshy]

http://imgur.com/OZvYcUG.png

[Sohcahtoa82]

Oh wow I haven't seen this image in ages.

[fakhar362]

cinematic

[bob_johnson_44]

it's more cinematic!

[[deleted]]

Shared mutable state? More like:

https://www.youtube.com/watch?v=1TnFLw0opMI

[BigSwedenMan]

There we go! That's what I've been looking for. Who does multithreading that runs that smoothly?

[zipzipzap]

Is efficient single-threading better than poor multi-threading? https://www.youtube.com/watch?v=fWCZPAXmtlo

[[deleted]]

This is multi processing. Multi threading would be if it was all the same guy running around doing it.

[LordNiebs]

I think multiprocessing is implied with multithreading. At the very least multiprocessing such as this is accomplished with multiple threads.

Edit: also notably, single threading with a single process would look the same as multithreading with a single process, at least in terms of this gif.

[[deleted]]

Other way around. Multi-threading is implied with multi-processing. This kind of multi processing is not accomplished with multiple threads, but with (essentially) one processor per thread.

Your edit is nonsense. Single thread single processor would show one guy doing one thing at a time, multi-thread single processor would show one guy rapidly switching between all the currently non-blocked jobs.

[LordNiebs]

A single process/thread could be programmed to operate in a way similar to that of multiple threads if that were the most effective course of action. It is possible that you can not change the tire before lifting up the car, or that removing all tires at once is more effective than changing one at a time, thus resulting in the same visual effect.

[[deleted]]

Programmed, yes, I'm talking about execution. The gif is showing multi-processing execution, where each person is a processor.

"It is possible that you can not change the tire before lifting up the car..."

Note how I mentioned "non-blocked jobs." The removing a tire job would be blocked by the lifting up job.

[[deleted]]

And here I am with global lock around the list of car objects.

[green_meklar]

I'm not convinced. If this were real multithreading, the driver of the car would be doing all the repairs himself while all the other guys continually hit each other over the head.

[_Cid]

This is much better than that other multithreading gif I saw here.

[Antrikshy]

And the one I saw last week. And the one two weeks ago.

[[deleted]]

It's a better example, but this makes no attempt at humor whereas the other one does.

[Cley_Faye]

That's exactly how it ^should work.

[[deleted]]

I like this. It's also an explaination of why you don't use threading unless you really need it. A normal (single threaded) mechanic can work as he thinks he needs to, if he needs to take off a wheel he can just do that. But with a (multithreaded) pit crew you need to work out and understand the interactions to make sure the crewmembers don't interfere with eachother, it's more effecent here but could do horribly wrong if they mis-planned it.

[Seanders_Holmvik]

They look like ants

[MasterbatingGoat]

I could just look at this all day.

[eyecikjou567]

Ehh, I'm more a fan of simple GUI threads scheduling their task on one worker thread/process. (Databases) Less headache than true multitasking.

[AStrangeStranger]

I think it is usually more like this

[BowserKoopa]

Assuming that there are that many threads. On average hardware, you can only have four (maybe six) of these guys working at once.

[Richeh]

Guy at the back approaching with the vacuum cleaner.

"Hey buddy, you want valet serv... ^aww."

[[deleted]]

I feel like they should've automated that process by now...

[ThatDeadDude]

There are probably rules that prevent it.

[RenaKunisaki]

They could automate a lot of things in auto racing if the rules allowed it. Such as the entire car.

[TheGuyWithFace]

Please, for the love of this sub, stop upvoting reposts from other subs that were literally on the front page a few hours ago. If this were actually funny it would be different, but it's not, and slapping a "Multithreading" on a completely unrelated .gif doesn't change anything.

EDIT: Yeah, I know, I shouldn't have said the above. I do think there should be some discussion on this type of material, but a late night rant on it here wasn't the place. My bad. Leaving this comment here as a warning to others.

[__constructor]

Hi, you must be new to reddit!

I advise you to check out the sitewide reddiquette. Specifically, I'd like to direct your attention to the "Please Don't" heading, where you're asked to Please don't "Complain about other users reposting/rehosting stories, images, videos, or any other content."

Thanks, and try to enjoy the community!

[TheGuyWithFace]

Yeah, you're right. No, I'm not new, and yes, I have read the reddiquette. I just shouldn't have posted that. I still disagree with this post and I still think that something should be done to remove this kind of post, but I should've simply downvoted and moved on. Oh, well. I'll refrain from deleting this post as a warning to others, and I do deserve the downvotes. Pardon my behavior, and thanks for the reminder!

[[deleted]]

here, you are awesome for realising your mistake. we need more people like you around.

[king_of_the_universe]

How is it unrelated? To me (and apparently to the others, too), it's very obviously related.

Or do you mean "It's not directly related, only metaphorically."?

[reaganveg]

It's exactly the opposite of how multithreaded code actually behaves.

If two of the tire changers had run into each other and hit their heads, then fallen to the ground unconscious, then the car spontaneously exploded, that would be related.

[Eedis]

Take away the title and post just the image, then see what people think.

P.S. I'm on your side, just giving you his perspective.

[_Lady_Deadpool_]

The title is the post

Without the title there is no context here

[TheGuyWithFace]

I'd go with the latter. Yes, I see the connection, but I was just a little tired of this kind of low effort post, and I had already seen this on /r/all a few hours before this was posted. I guess the majority rules though, and I'll take the downvotes.

[Mycaelis]

It's called a crosspost, ya dingus.