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Mysterious Android codebase commit

android.googlesource.com

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Re: Mysterious Android codebase commit

#101

Post by quotemstr »

saurik wrote: post #100
quotemstr wrote: post #94

Earlier quoted context omitted.

MVM relies on the runtime system to enforce security isolation. In a system like Android that allows unrestricted loading of native code, this scheme can't work, since there's no way to get arbitrary native code to play along with the runtime security model. Personally, I feel much more confident with the kernel enforcing application isolation than I would feel about relying on the Java security model.

As a sibling comment pointed out, Android already does this. To learn (an insane amount of) more detail about how this works, read this article I wrote a while back on how Process Loading on various systems is optimized. http://www.cydiasubstrate.com/id/727f62ed-69d3-4956-86b2-bc0...

It's not the same thing at all. Android first makes a process template, then takes clippings for each process it wants to run. That's not the same as running different applications in the same process.

Re: Mysterious Android codebase commit

#102

Post by [deleted] »

overgard wrote: post #31
grizzles wrote: post #26

Earlier quoted context omitted.

The JVM is already open source. If this matter has indeed been settled, then the litigious organization issue might have been too. WebAssembly doesn't have a GC, and probably won't for some time. It also doesn't have ~20 years of performance tuning on different microarchitectures the way the JVM does. Benefits include getting scala, clojure, jython, jruby, and about 30 other languages working client side in the brows…

> WebAssembly doesn't have a GC, and probably won't for some time. Yeah... because it's assembly. That's the whole point. You don't WANT a GC. It would be the wrong layer to place a GC in. Ask most professional game developers if they would consider using a platform with a GC. They won't, because you can't build a realtime system without stuttering if you're dealing with a GC.

[deleted]

Re: Mysterious Android codebase commit

#103

Post by rewqfdsa »

pron wrote: post #67
rdtsc wrote: post #66

Earlier quoted context omitted.

> The JVM is already open source. From what I understand open source and imunity from litigation are orthogonal. Open source code and still be a patent minefield.

OpenJDK has a full patent grant[1]. It is 100% open source in every way possible, its use is unrestricted, and it is released under the same license as Linux. AFAIK, Oracle has never sued anyone making use of it for whatever purpose whatsoever. It is important to remind the undisputed fact that -- at least so far -- Google has chosen not to use OpenJDK (or, in any case, they did not comply with its license), and ther…

Of course, if you don't conform, Oracle will sue you into oblivion. Java is free software as long as you use it in exactly the way Oracle wants, right? It's for this reason that Java is poison to any of my projects. I'll choose Node-fucking-JS over Java, because nobody is going to sue me for using JavaScript the way I want.

Re: Mysterious Android codebase commit

#104

Post by Raphael »

pjmlp wrote: post #89
makomk wrote: post #86

Earlier quoted context omitted.

I'm pretty sure those constrained devices are running bytecode interpreters that aren't nearly competitive with native code in terms of speed, with UIs that wouldn't cut it on even a low-end smartphone these days.

Then you should educate yourself, as they are running JIT and AOT code. I can provide links for product documentation and real products if you wish.

Every time an Android device installs its monthly security update, it spends an inordinate amount of time, with the screen on, "optimizing" every single app.

Re: Mysterious Android codebase commit

#105

Post by pjmlp »

Nitramp wrote: post #90
pjmlp wrote: post #89

Earlier quoted context omitted.

Then you should educate yourself, as they are running JIT and AOT code. I can provide links for product documentation and real products if you wish.

pjmlp: original poster above referred to Hotspot, not arbitrary JVMs. Clearly Android devices can run VMs with both JIT and AOT (they do, after all), what OP questioned was whether Hotspot in particular (not some arbitrary VM) is a good VM on a mobile device. Given Hotspot's somewhat underwhelming startup speed even on desktop class computers, I think that's a very reasonable technical question to ask, and not FUD in…

Hotspot requires as little as 128 KB RAM and 1 MB ROM

http://www.oracle.com/technetwork/java/embedded/javame/embed...

If one adds the GUI client APIs, then the whole SDK grows up to 5MB ROM.

http://www.oracle.com/technetwork/java/embedded/javame/embed...

Some commercial products using the above runtimes are the Gemalto's M2M modules or evaluation boards like the ARM Keil F200.

But I expect Google fanclub to downvote me.

Re: Mysterious Android codebase commit

#106

Post by pjmlp »

rewqfdsa wrote: post #103
pron wrote: post #67

Earlier quoted context omitted.

OpenJDK has a full patent grant[1]. It is 100% open source in every way possible, its use is unrestricted, and it is released under the same license as Linux. AFAIK, Oracle has never sued anyone making use of it for whatever purpose whatsoever. It is important to remind the undisputed fact that -- at least so far -- Google has chosen not to use OpenJDK (or, in any case, they did not comply with its license), and ther…

Of course, if you don't conform, Oracle will sue you into oblivion. Java is free software as long as you use it in exactly the way Oracle wants, right? It's for this reason that Java is poison to any of my projects. I'll choose Node-fucking-JS over Java, because nobody is going to sue me for using JavaScript the way I want.

No one expects JavaScript to run unchanged across all VMs anyway.

Re: Mysterious Android codebase commit

#107

Post by bitmapbrother »

pron wrote: post #61
bitmapbrother wrote: post #52

Earlier quoted context omitted.

Option two wasn't even worth mentioning. There is absolutely no way Google is going to abandon ART and switch to a significantly less performant VM. AOT is here to stay.

A JIT makes many tradeoffs but it is always capable of producing code at least as good as an AOT. How much better that code is depends on many factors, such as the language, the application, and how much time/energy you're willing to spend on optimization (the latter might lead to choosing to generate code that's less optimized than an AOT). A slightly bigger difference is not between JIT and AOT, but whether you can…

Of course a JIT is capable of producing code as good as an AOT and perhaps even better since it can capture more profiling data. The problem with a JIT is the startup time and this has not gone unnoticed by Oracle as even they've started working on AOT.

Re: Mysterious Android codebase commit

#108

Post by pron »

rewqfdsa wrote: post #103
pron wrote: post #67

Earlier quoted context omitted.

OpenJDK has a full patent grant[1]. It is 100% open source in every way possible, its use is unrestricted, and it is released under the same license as Linux. AFAIK, Oracle has never sued anyone making use of it for whatever purpose whatsoever. It is important to remind the undisputed fact that -- at least so far -- Google has chosen not to use OpenJDK (or, in any case, they did not comply with its license), and ther…

Of course, if you don't conform, Oracle will sue you into oblivion. Java is free software as long as you use it in exactly the way Oracle wants, right? It's for this reason that Java is poison to any of my projects. I'll choose Node-fucking-JS over Java, because nobody is going to sue me for using JavaScript the way I want.

> Of course, if you don't conform, Oracle will sue you into oblivion.

What? OpenJDK is as free as they come. No conformance with Java necessary, you can do with it whatever you damn well please. You can use it to implement .NET if you want. Oracle has never (to the best of my knowledge) sued anyone for the use (or modification) of OpenJDK.

Re: Mysterious Android codebase commit

#109

Post by rewqfdsa »

pron wrote: post #108
rewqfdsa wrote: post #103

Earlier quoted context omitted.

Of course, if you don't conform, Oracle will sue you into oblivion. Java is free software as long as you use it in exactly the way Oracle wants, right? It's for this reason that Java is poison to any of my projects. I'll choose Node-fucking-JS over Java, because nobody is going to sue me for using JavaScript the way I want.

> Of course, if you don't conform, Oracle will sue you into oblivion. What? OpenJDK is as free as they come. No conformance with Java necessary, you can do with it whatever you damn well please. You can use it to implement .NET if you want. Oracle has never (to the best of my knowledge) sued anyone for the use (or modification) of OpenJDK.

Okay, so can I modify it so that it doesn't conform to the Java specification? Can I modify it bit-by-bit until it's bytewise identical to Harmony? Of course I can't. Because if I do, Oracle will sue me.

Oracle is lying. They claim to be offering free software, but will sue you once you take advantage of that freedom. It's a fucking trap.

Do you really expect the technology community to embrace Oracle technology after Oracle spits in their food and shits in their sink?

Re: Mysterious Android codebase commit

#110

Post by bitmapbrother »

quotemstr wrote: post #53
bitmapbrother wrote: post #52

Earlier quoted context omitted.

Option two wasn't even worth mentioning. There is absolutely no way Google is going to abandon ART and switch to a significantly less performant VM. AOT is here to stay.

> AOT is here to stay. No it isn't. Read the source. ART has a JIT now.

As far as Android is concerned - AOT is here to stay. And yes, I'm aware ART has a JIT and it's probably used for devices that cannot handle the overhead of AOT, but I imagine it's seldomly used considering the specs of today's phones and the requirements of Google's CTS.
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