Getting C++ Threads Right

[ShadowSky24]

GAH GET YOUR DAMN QUALITY RIGHT GOOGLE, this is so annoying.

Great video = Bad quality... so common these days, I hope this doesn't happen in 2020 (In the future)

[LuckyLuke364]

This would be great if youtube would actually stream it without pausing every 20 seconds (I'm on a 18MBit connection)

[Oscillor]

this could have been interesting if youtube didn't exit fullscreen on pause

[krisiii1234]

/watch?v=ps0QOaqcrII

[Omnifarious0]

@rahulrvideo, @robnox - Whether or not Python is slower than C++ depends a lot on the application. I can promise you that if you're implementing 'cp' you will not notice any difference in speed between the two. You will only notice a difference when your program is CPU bound.

That said, the factor of '1000' is believable in some instances, and as an average for a bunch of benchmarks I'm fully willing to believe it. But don't think that kind of measurement tells the whole story.

[VideoFilterGuy]

He is a bit nervous about public speaking, its pretty common, most people are uncomfortable talking to groups.

[daspil0t]

Jesus Christ, he's talking way too hectically. His irregular breathing is catching...

[llothar68]

I'm using Boehms garbage collector a lot in my private in-house compiler. Nice to finally see his face - i expected him to be older.

[bogoid]

I love how software developers (wannabes included) tie themselves to programming languages.

Languages die people, get over it, sooner or later every language will die.

[non91]

@bogoid not entirely true..

[bogoid]

@non91

so which is the language that will never die, and why?

[non91]

@bogoid well technically people still use assembly and thats been around nearly as long as electronic computers and languages like C++ are very old too and are still very popular .. and i dont see the need for new languages atm and i dont see how old languages would die without anything new so..

[VideoFilterGuy]

@non91 Assembly will always be around as it is merely a human readable mnemonic representation of machine language, which is the raw bits the processor uses. C++ is very likely to be around forever as well. 'New' languages like C# and Java are really more solution in search of a problem. C++ does everything C# and Java do. Some languages are special purpose like SQL and PHP, where the language is neither intended nor suited to application or OS programming.

[non91]

@VideoFilterGuy i think i was trying to say that.. but nevertheless nicely put :)

[acrvn]

@bogoid each one is gonna die

[robnox]

@johnyfartpants you can write the graphics thread in C/C++ and then load that module in Python and the graphics will be liquid smooth because the Python runtime isn't managing all the gfx logic, your library is. or better yet, write it in assembly! ;)

[dudeinasuit321]

dang this guy has a lot of other hands haha

[z0ltanz0ltan]

GIVE DEES PEOPLE EEYA!

[robnox]

I do mostly 3D graphics, stuff you cant do with Python because it's too slow. The number "1000" isnt just something I made up, it was 1000 times slower than C++ in benchmarks

[z0ltanz0ltan]

@robnox Internet thug. Heh.

[rahulrvideo]

@robnox i would really like to know if u could provide some cogent evidence to substantiate your claim.. about c++ being 1000 times faster than python....

[robnox]

@rahulrvideo Google "python vs c++ speed" it will be the 3rd result. I tested this in house with an assembly based timing mechanism (for more accuracy) and I got approximately 1000 times faster execution vs python

[llothar68]

@robnox

I don't agree with your python performance bashing. I measured a zip algorithm and python was only 270 times slower then C++. But yes i had to apply tricks to get it this fast :-)

But it's okay for moving strings around and concatenating them to make webpages.

[robnox]

@llothar68 only 270 times slower than C++.. I rest my case lol. that reminds me of a benchmark I once did Intel Core2 vs i7 with tar -xjf ran approximately 10 times faster on the Core2. This was when the i7 just came out and GCC had no compiler optimizations for the i7 yet, so I think this is the main contributing factor. my point being, optimizations go a long way ;-)

[johnyfartpants]

@robnox if you can't do 3d graphics, how does eve-online run then as this is programmed in python iirc?

[robnox]

I dont find C++ much more difficult to write than python, and the code you compile with C++ will execute over 1000 times faster than python. Is saving a few minutes of programming really worth code that runs 1000 times slower?

[EXetoC]

@robnox You don't find it that much more difficult? have you ever written any code for applications that are more complex than "hello world"? I doubt the speed difference is that big. feel free to prove me wrong though.

[robnox]

Ahh, C++, the last "real" programming language. Java, C#/.NET, Python, all are a joke when you compare them to C/C++

[rahulrvideo]

@robnox well , i dont agree when it comes to python . python is way better than "C" . Its built on C , but makes the code very very laconic and substantially lesser than u write in C .

[itachisxeyes]

@rahulrvideo i dare you to code me a kernel in Python (^_^)

there is no "better" language (this goes for the other guy too) just different applications. now the validity of some languages is questionable (like BASIC). C is a great language. and Python has its uses too, its a lot easier to manage then Perl on server side i'll tell you that.

and as far as the last real programming languages goes...that would be 80x86 Assembly (>_>) (<_<)

[enotdetcelfer]

COME WITH ME IF YOU WANT TO LIVE ARRGUH

[WrestlingFanUploader]

lol this guy sounds texasly german lol

[killah51staemme]

@WrestlingFanUploader his motherlanguage is hebrew..

[amino0o]

half american half german accent

[ANGELxINxDESARKNS]

wow you dont realize how stupid you are, maybe you should do more research on your buddy Alex Jones. FFS

[joelwhitehouse]

Wow - the example at 37:00 is something I've dealt with. I'm glad to have seen this!

[MasterMind300]

LOTS OF THINGS ARE DONE IN C/C++

[LongSausageMAN]

And what does that mean ? You make a statement like that with no bases what so ever.

[cyborgtroy]

Screw your spamming, but I like the idea.

For some reason, game consoles are the only PCs to have multiple controllers and split-screen. If only people thought to make split-screen games for desktops and to just buy USB controllers, we wouldn't even need game consoles.

[RyanPridgeon]

One of the main reasons why consoles are so popular is price.

[ProgramMax]

Great talk. I appreciate all the hard work and research you put into this.

I have a question. I seem to recall hearing somewhere that in VC if your switch cases are in incrementing order starting with 0 then it will make a branch table. I've never actually checked this.

Your video shows the switch nested inside an if to make sure the variable being switched over is within a range. Is this required? Can't the compiler see I only have 3 cases?

Thank you! :D

[JustMaximumPower]

the compiler only checks the cases and the variable if you use a default case.

[colinmaharaj]

Have been using threads for many years. Like the guy said, I did not get it right the first time, so it seem dawnting, but I am now very comfortable with C++ threads in Windows and have a simple application that probably has about 5 - 15 threads (depending on what you turn on in the application) runnig 24x7.

[FlameHue]

Once you try D you won't go back to C++

[chaco1776]

Afen, wai are we intersted in the THREADS...

[imitabilis]

sounds like Schwartzenegger, especially when he says "er..." after almost every sentence.

[Dlucas1357]

no time for an hour plus

[Lordcorm]

MACs are for people who dont have the knowledge to use PCs.

[creeparraid]

agreed MAC computers are more user friendly MAC Os systems hide most of the functions that the PC leaves open for Admins Ex. .dll fills and system files mac computers are low matanace comps unlike PC to use a PC right you must know a farely good bit about computers the Vista XP and other OS's on Pc's are still user friendly but not as much as a Mac a Windows based computer has nothing on a Linix or unix based computers but all in all Mac and PC are = computers in hardware and software

[creeparraid]

but each is better for diff ppl in ther own way a newer computer user may find it better to work with a mac as a officer manager may find it better to use a PC with a windows OS when you look at it Mac VS. PC is nothing more than Nike Vs. Vans just 2 diff brands made for two diffrent things one may favor the other but hwen you look at it from a consumer veiw mac has a more appeling veiw

this coment was suposed to be placed below

Kin632s coment under Sirus20x6 :P

[computerfis]

THEN YOU REALLY DIDNT SEE YOU AROUND

[noel21613]

What do you mean

[Kin632]

how do you compile files on a mac???

[Sirus20x6]

you buy a real computer and get a compiler.

[pepemark]

get a compiler.

[blahandbleh]

"i'll be back"

[VoiceOfThePlanet]

"Get to the chopper..NOW!!!"

[gammooo]

"Get down!!!"

[MrNotchJohnson]

"I need your clothes, your boots, and your motorcycle."

[999emanresU]

Good lecture for compiler writers, not so good for users of compilers. If you are scared of threads now, watch this and get REALLY scared.

As his slides show, you have to write really bad code to maybe get these bugs to show up --like multiple writes to unprotected shared bitfields. Well duh--that might cause you a problem.

Im glad C++ is fixing this stuff, but this lecture isnt going to help you write better MT apps.

[gravyjones]

Interesting, but this talk only holds up in a purely engineering sandbox. Jump into userland with user interface and useability problems and you can't get away from locks and events. He should focus his obvious intelligence on convincing people to seperate an interface from an implementation and then present a design pattern to deal with the multithreaded issues of those portions of the implementation that require multithreaded techniques.

[gmvsea]

Great lecture. Luckily, I use Java :-)

[mayorc]

hehehe me too :)

[frham20]

yeah but just like he mentionned, many JVM are broken ;)

[a1mint]

Lots of C++ people have their heads in the sand.

[Baraclese]

Mmmmmmmmmm sand.