ubuntu-phone team mailing list archive

[Luke Bryan <luke32j@xxxxxxx>]

Thanks for the info! That's an interesting article on Javascript and performance. It seems low memory of mobiles, and better performance, are the reason Ubuntu will be going with mostly Qt/c++ for mobile apps? I'm more of a fan of Python/Java programming, but I can see why this may be beneficial. I hope Pyside/QML will be available at least for Ubuntu-phone, that would be very handy.

Best regards,
Luke
Date: Sun, 14 Jul 2013 18:11:39 -0500
Subject: Re: [Ubuntu-phone] Memory question
From: coder543@xxxxxxxxx
To: luke32j@xxxxxxx
CC: ubuntu-phone@xxxxxxxxxxxxxxxxxxx

Java is hardly the major multicore programming language. Let's get that out of the way first. Also, libreoffice has been rewritten into C++ over the last few years. If any Java remains, it is rapidly becoming inconsequential. I do agree it has been the dominant platform for dumbphone apps, but that has zero impact on Ubuntu. As far as smartphone apps... No. The java language is being used on Android, but it's using the Dalvik VM, not standard Java libraries and all that. We couldn't support those apps even if we wanted to. It would be a terrible plan. This has been discussed numerous times on the mailing list -- use Google to search the mailing list if you have to. Why would you have to use JavaScript web workers? Why would those even be helpful? JavaScript is not Java, at all. It's actually ECMAScript even though it goes by the misnomer of JavaScript, but I still don't see why those would be necessary when you can simply write some multicore C++, or C, or whatever. Go and Rust are perfectly capable multicore oriented languages too.

Java is unnecessary, but more importantly, it has bad performance characteristics. It needs significant amounts of RAM to avoid the garbage collector thrashing the CPU. This article goes into great depth about why Java and JavaScript naturally perform poorly on mobile devices: http://sealedabstract.com/rants/why-mobile-web-apps-are-slow/

The guy is very wrong about some of the hardware aspects in that article, particularly regarding the relative speeds of ARM and x86, but his analysis of the software side of things is fairly competent.
Ubuntu touch is centered around Qt, being coded in a combination of QML, JavaScript, and C++, with any combination of those languages or just one.
On Jul 14, 2013 6:01 PM, "Luke Bryan" <luke32j@xxxxxxx> wrote:




What do you mean by, Ubuntu won't use Java? Java has been the major multi-core programming language, the platform for smartphone and "dumb-phones" apps, and has come with Ubuntu by default, for a long time now. So will Java, and apps like LibreOffice now be unsupported? Will we have to use Javascript web-workers instead, for high performance multicore applications?


Best regards
Luke

Date: Sat, 13 Jul 2013 21:15:03 +0200
Subject: Re: [Ubuntu-phone] Memory question
From: gianguidorama@xxxxxxxxx

To: coder543@xxxxxxxxx
CC: ubuntu-phone@xxxxxxxxxxxxxxxxxxx; luke32j@xxxxxxx


And after all Ubuntu doesn't use Java, so I think that memory consumption will remain at a reasonable level. 
Il giorno 13/lug/2013 21:06, "Josh Leverette" <coder543@xxxxxxxxx> ha scritto:


Android only does that when it has to, meaning devices with low memory available. I'm sure Ubuntu will kill apps when it has to, and not a moment sooner.
Sincerely,

Josh
On Jul 13, 2013 11:28 AM, "Luke Bryan" <luke32j@xxxxxxx> wrote:





Greetings,

I was wondering about apps for Ubuntu-touch regarding memory. Will ubuntu-touch have the (somewhat annoying) feature of killing off apps that go over 16 or 20 mb (or whatever limit set on the device), as Android does? This enforces app developers to not make memory-hogging applications, but it's annoying for the user. Maybe there should be a developer-option to warn when much memory is used?




Best regards,
Luke
 		 	   		  

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