Out of curiosity, when running a UIWebView on iOS, is it running full WebKit with JIT enabled, etc, or is there something dumbed down about it?
Ted On Jun 23, 2012, at 10:35 PM, Tim Caswell wrote: > The difference between V8 and most other scripting languages is that V8 does > not have an interpreter. It is JIT only. That means it works by 1. writing > machine code to memory, 2. executing the code. JIT is very fast and most of > the modern scripting engines do it (V8, JSC, SpiderMonkey, LuaJit, ...). All > of these engines (except for V8) also have an interpreter mode where the > machine code is fixed at compile time and it walks over your script code > interpreting it. State is kept using various data structures like one big > state machine simulating a CPU that knows how to run JavaScript natively. > This is slower, but doesn't require using the same region of memory as both > writable and executable. > > On Sat, Jun 23, 2012 at 9:09 PM, Ryan Schmidt <google-2...@ryandesign.com> > wrote: > > On Jun 23, 2012, at 17:13, Jorge wrote: > > > On 23/06/2012, at 19:03, Ryan Schmidt wrote: > >> > >> On Jun 23, 2012, at 02:37, Jorge wrote: > >> > >>> I don't know the answer to your question, but my guess is that many of > >>> the things that node does won't run/can't be done in a sandbox. I believe > >>> the experiments with node on iOS so far have always been in jailbroken > >>> devices. But I may be wrong. > >> > >> Certainly, being able to run in a sandbox will be necessary, since Apple > >> will not approve apps anymore that don't. I haven't tried it yet, but why > >> do you think node won't run in a sandbox? > > > > iOS wont't let user code jump into a block of writable (from your app's > > point of view) memory -for security reasons- > > That seems reasonable. > > > > and it seems that v8's JIT compiler requires that: > > http://code.google.com/p/v8/issues/detail?id=1312 > > Thank you for the link, but I think the discussion goes over my head. It > talks about mapping executable memory pages, which are concepts I'm pleased > as a JavaScript developer not to have to know anything about. On the surface, > I don't understand why the block of memory containing my program code should > need to be writable. I'm not wanting to change my program code as it's > running. I'm just wanting to run it. Or are you saying that by virtue of > being an interpreted language it must be writable? Also, that issue was > started over a year ago, and has not been touched in six months. There is a > patch attached to implement some improvement, and there's no indication > whether it was committed. Maybe something has already changed? Or if not, > maybe it's time to remind the v8 devs about it? > > > > The Nitro JIT in JavaScriptCore in mobile Safari requires that too, but the > > security measure has been conveniently lifted for that particular app :-P > > The second article I linked to in my original post mentioned Apple relaxing > its restrictions on interpreted languages, in recognition of the fact that > many games use scripting languages like lua. Does lua also run code in > writable memory? If so, how are they bypassing Apple's requirement? And if > not, is there something we can learn from how lua is doing that that could be > applied to improve node / v8? > > > > Also it seems that quite a bunch of the usual posix APIs simply aren't > > there... until you jailbreak it and install the things yourself. > > I'm not interested in jailbreaking devices; I'm interesting in creating apps > users on everyday iOS and OS X devices can install. I'm not familiar with how > sandboxing works in OS X or iOS. I haven't found out yet how I could build a > sample sandboxed application to play around with it either. What specific > POSIX APIs that node needs will be unavailable? > > > > Apple wants you to develop your apps using their cocoa APIs not anything > > else. Soon we are going to suffer similar constraints (sandboxes etc) in > > Mountain Lion too. And finally a day will come when nothing but Apple's > > approved apps (that is: from the mac app store) will run in a Mac... "for > > your security". > > I can't speculate on what direction Apple might go with future versions of OS > X, but concerns like these are precisely why I started this thread. In light > of the current and potential future security restrictions, how can we use > node and NodObjC to develop an OS X or iOS app? It's no use to spend time > developing an app if it can't be distributed to end users. > > > On Jun 23, 2012, at 19:43, Tim Caswell wrote: > > > I don't think there is a way to get nodejs using V8 running in an app-store > > friendly format. > > Again, why? Is it the same concerns Jorge expressed above? > > > > But I would love to get libuv and some scripting engine running there. I > > may try my luvit project first (luajit + libuv) or luvmonkey (spidermonkey > > + libuv). Another combination would be JSC + libuv. > > I'm interested in getting node and NodObjC usable for making OS X and iOS > apps. The promise of using JavaScript for both server side and client side > (web and app) programming is very appealing. I simply want nothing less than > what the NodObjC homepage advertises: "So you can write entire Cocoa or iOS > GUI applications entirely in NodeJS JavaScript!" > > > > > -- > Job Board: http://jobs.nodejs.org/ > Posting guidelines: > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > You received this message because you are subscribed to the Google > Groups "nodejs" group. > To post to this group, send email to nodejs@googlegroups.com > To unsubscribe from this group, send email to > nodejs+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/nodejs?hl=en?hl=en > > > -- > Job Board: http://jobs.nodejs.org/ > Posting guidelines: > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > You received this message because you are subscribed to the Google > Groups "nodejs" group. > To post to this group, send email to nodejs@googlegroups.com > To unsubscribe from this group, send email to > nodejs+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en
