Android Ported to C#

http://blog.xamarin.com/2012/05/01/android-in-c-sharp/

by pmjordan • 14 years ago

516 165 14 years ago

blog.xamarin.com

untog4• 14 years ago

Fascinating, especially in the light of the Google Java issues right now- the performance graphs are just the icing on the cake.

Mono has traditionally had a reputation as being a lot slower than .NET- perhaps that isn't the case any more either? It would be great to see some independent third party figures on this.

It's funny that the MS created C# is one of very few languages that lets you make native apps in iOS, Android and WP.

gravitronic• 14 years ago

I've been successful in using C++ (with libSDL) to write apps for Android, iOS, QNX (PlayBook) and WebOS (RIP).

Whats more bizarre is that windows phone 7 does not have a development kit for using C/C++. Only C#/XNA. I've heard on HN that this may change for WP8. I hope so.

HardyLeung4• 14 years ago

WP8 and Windows 8 are definitely very C++ friendly. I actually think that C++ may be the language to rule them all as the next generation of web application goes beyond what Javascript can handle. Well, that and C# given Miguel's effort.

I can develop ONE piece of core logic, and have it run on iOS, Android, Windows, Mac, even web (via NativeClient). I posted an AskHN about this earlier today (though not much interest). That sounds like a win.

yread• 14 years ago

Some of the more high profile apps on WP7 have huge native blobs in them. So if youre important enough MS might choose to share their toolkit

cageface12• 14 years ago

How do you bootstrap an SDL app on iOS? I've been considering taking this route myself because I really hate multi-language development and all my DSP code is in C++.

jlawer2• 14 years ago

Well microsoft didn't make C# cross platform, that was all really the mono guys.

aespinoza2• 14 years ago

You are right, but it is still funny though.

moonchrome2• 14 years ago

But they made it an open standard (and are regularly updating it), which goes against the general perception of "M$".

saurik3• 14 years ago

Back when .NET was still in beta, I was flown up to Redmond to provide some feedback on Managed C++. I specifically asked them why their Socket API was "crippled" in comparison to WinSock (which has some really beautiful mechanisms for handling things like cross-protocol addressing), and the answer I got was "portability to non-Windows systems".

MichaelGG2• 14 years ago

Not to detract from the Mono team's awesome achievements but:

- Microsoft has released a cross-platform CLR ("Rotor"). Win/Mac/BSD I believe. - C# and the CLR are ECMA specifications. - A lot of the class libs are definitely not Windows only. - Microsoft also has Silverlight (CLR) running on Mac, if that counts.

The whole .NET stack, apart from some Windows specific libraries (some COM+ management stuff, Win Forms) were definitely made to be cross-platform.

acak• 14 years ago

Forgive my ignorance. Which application lets you write native iOS apps in C#? Thanks.

d503• 14 years ago

MonoTouch http://xamarin.com/monotouch

untog4• 14 years ago

The guys who made this blog post make some software called MonoTouch.

http://xamarin.com/

It costs $400 for a license, though. But boy I am tempted... I know, I know- you need to go with the native languages for the best experience. But keeping a huge chunk of my codebase between platforms is a very, very interesting idea to me.

philjohn• 14 years ago

MonoTouch

bryanl• 14 years ago

People have responded with MonoTouch, but there is also Unity3d http://www.unity3d.com. You can author games for quite a few platforms with it.

sambeau• 14 years ago

Unity

http://unity3d.com/unity/pro/#extend

rabbitfang• 14 years ago

Regular Java is currently faster (up to 3x) than C# on mono: http://shootout.alioth.debian.org/u64q/benchmark.php?test=al... ...but obviously on a phone it's going to be Dalvik not regular JVM

We need to consider memory consumption too. Dalvik obviously uses less memory than regular JVM, and probably less than mono if I were to guess.

raverbashing• 14 years ago

I'm guessing the JVMs have gone a long way on optimization (or maybe they're using JIT)

Also not sure about how optimized are the C# sources in relation to the Java sources

For example, in the Mandelbrot benchmark there are several differences

- Java uses more arrays

- C# and Java use different break conditions

- Calculations are done differently (with similar results)

Overall they're doing the same things, the C# is more like I remember it, so I'm guessing the Java code has some smart tricks up its sleeve

jeswin2• 14 years ago

Well, don't read too much into it.

Here is the Java source for binary-trees, which is 6x faster than c#. http://shootout.alioth.debian.org/u64q/program.php?test=bina... C#: http://shootout.alioth.debian.org/u64q/program.php?test=bina...

Notice that the Java code multi-threaded, while the C# version is single-threaded. And the Q6600 being used there has 4 cores.

migueldeicaza7• 14 years ago

Some observations:

In general, HotSpot is a more advanced VM that Mono is. They support dynamic recompilation at a higher optimization level, which we do not.

This is part of the debate in Google vs Oracle. Google could have used HotSpot had they figured out some agreement, but instead ended up with Dalvik which lacks many of the advanced optimizations of HotSpot.

That said, java -server compared against out of the box Mono 2.10.8 is not an apple's to apple's comparison, it is by no means "regular Java". That is Java tuned with some specific parameters. It comes at the expense of interactive time, Mono's default is fast-JIT, and fast startup.

Java -server uses a fixed heap, this means that you must preallocate how much memory the application will use during its entire lifetime. This is good for performance because the GC knows that it only has to scan for example memory between points A and B. 2 comparisons is all you need during GC to scan. Meanwhile, Mono is uses a dynamic heap, which means that it can grow its memory usage based on demand (no need to fine tune the maximum heap every time your app crashes due to a low setting) and can return the released memory to the OS. This complicates GC, because now we cant just compare against 2 values, we need to consider every object in the scope of a series of differently sized heaps.

With Mono 2.11, you can force your app to go fixed heap; The only people that really have a use for this are HPC people and a handful of server people. To be honest, most people dont want to configure the max heap of their server apps by crashing and trial and error.

The second component is that Mono's default is aimed for desktop/mobile configurations, not server loads. If you want to use server loads, run Mono with the --llvm flag: you will have very slow startup times, but you will get code quality that is essentially the same code quality that you get from an optimizing C compiler nowadays.

As for Mono vs Dalvik memory use, in practice people run Mono with Dalvik (Mono for Android), not in standalone mode, so we end up paying for Dalvik's memory footprint. But I agree, it would be nice to find out how much memory it actually uses.

Considering that we get the benefits of a more advanced GC, value types and generics while Java does not, it just seems like we would use less memory for comparable loads.

saurik3• 14 years ago

No one has made this specific point yet, which I've found surprising: it does not matter whether Mono is faster than .NET, it only matters whether Mono is faster than Dalvik.

azakai• 14 years ago

Not necessarily. High-performance apps on Android are written in C++ and RenderScript anyhow, not Java/Dalvik.

jurre• 14 years ago

Lately I've been thinking that Haskell might be a really good language to write cross platform native apps in. It's super fast but also high level so you can be really productive. I know there are some libs for iOS but if some sort of cross platform framework existed I think it could be really powerful.

kamechan• 14 years ago

not sure that C# is the answer either, given that microsoft is trying to build a nest in the mobile space. that said, nice work.

poses an interesting question though: if google had to or wanted to switch platforms/languages, which might they choose?

untog4• 14 years ago

The article covers that, to some extent:

Unlike Sun with Java, Microsoft submitted C# and the .NET VM for standardization to ECMA and saw those standards graduated all the way to ISO strong patent commitments. The .NET framework is also covered by Microsoft’s legally binding community promise.

It's strange- with the work Xamarind has been doing, C# is one of the few language choices you have to go cross-platform and native- MonoTouch does iOS, MonoDroid does Android, and MS themselves do Windows Phone. I've not used any of these extensively so can't vouch for them, but it's an interesting development.

edwinnathaniel• 14 years ago

I was reading the wikipedia entry about C# a few days ago and was surprised to see the following bits:

"As of December 2010, no ECMA and ISO/IEC specifications exist for C# 3.0 4.0, and 5.0."

http://en.wikipedia.org/wiki/C_Sharp_(programming_language)

Does this mean newer syntax updates won't make it to Mono? or not as open as it used to be in terms of patent and copyright?

sgt• 14 years ago

Mono is useful on its own, even if Microsoft "backs away" from encouraging projects like Mono to exist.

bmj• 14 years ago

I believe the concern is that without ECMA/ISO standardization, there's nothing to stop MS from suing Xamarin/Mono should they decide to back away from an open language specification.

InclinedPlane• 14 years ago

C# the language is open, it's an ECMA standard. The only proprietary bits of C# are the .NET Framework and the Windows implementation of the VM (CLR), though even those are freely redistributable.

nextparadigms3• 14 years ago

Java was supposed to be open, too, perhaps much more than C#, and yet here we are today. Given Microsoft's recent patent history against Android and even ChromeOS, if I were Google I'd stay as far away as possible from C#, no matter how "open" they say it is.

Heck, at this point Google probably can't even trust Python anymore, seeing how there are patent and copyright leeches everywhere. Their best bet is to use a language they own, be that Go or another one they made or bought.

muyuu2• 14 years ago

There are valid concerns about the implementations of .NET and the possible ramifications that could come if Microsoft decided to enforce their patents surrounding them.

Having an open standard can be moot if effective implementations of it are patent-encumbered, forcing you to either use a licenced runtime, a second-class one, or risk getting sued.

Android Ported to C#

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