[v8-users] Sayonara, v8
Hello, all, (TL;DR: bye!) (i'm going to try to do this without a tone of contempt, and i apologize in advance if a bit of it slips through.) As many of you know, i've maintained the v8-juice and cvv8 (a.k.a. v8-convert) projects since March of 2009, have implemented tens of thousands of lines of v8 code since that time, and have written more documentation on the topic than the whole v8 team combined. The recent rounds of changes in v8, however, were a direct kick in the balls to both of those projects and every one of their clients, introducing incompatibilities which would take me weeks of full-time effort to get back into working order (in the form of a rewrite). i don't have the energy for that, especially when the v8 team as a whole doesn't have the energy to document their code, raising the bar of (re)entry into v8. That's the last time you'll hear me bitch about that, guys - my one-man unpaid projects regularly out-document your whole team and that is DOWNRIGHT SHAMEFUL[1]! So, here's my farewell not only from my v8 projects, but also from v8 in general. i understand and sympathize with Google's choice to improve v8 rather than be held back by compatibility crutches, but i don't have the energy to play the catch-up game with them, nor to evangelize v8 further. Per a recent post on this list from one of the Chromium devs, it look the Chrome team months to port to the new API, and i'm a single developer with 4+ years of accumulated code. Screw it - i've got more productive/less risky things to expend my energy on. i am, as of this moment, abandoning my v8 projects and looking for a capable C++ coder (or coders) to take over the v8-juice/cvv8 projects: https://code.google.com/p/v8-juice/ With the forewarning that the more interesting parts of the internals need a major overhault/rewrite due to the signature change of InvocationCallback (e.g. the basis of [2]). The vast majority of the core type conversions APIs should be unaffected. If you are interested, please get in touch _off list_. i won't be on this list much longer and won't see replies made here, nor will i be responding on-list to any responses made to this post. i wish you all Happy, Successful Hacking, and may your projects survive the Great V8 API Upheaval of 2013 (and any future upheavals!). [1] https://docs.google.com/presentation/d/1plJbtQZXKBymEiw9sYy9xqnzMleWuYO461R3VrocOWQ/view [2] https://code.google.com/p/v8-juice/wiki/V8Convert_XTo -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Re: New feature: handle eternalization
On Fri, Aug 9, 2013 at 8:54 PM, Mike Moening mike.moen...@gmail.com wrote: I know this may sound stupid... but how can I kill an eternal? Really nothing lives forever. I can think of a case where i might want to destroy one. This should do the trick: exit(0); ;) -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Crashing with HandleScope error before anything is done
On Sat, Jul 20, 2013 at 6:39 AM, Richard S blakpi...@gmail.com wrote: V8 is throwing an error about needing a handle scope before anything is even done in my app. It was working fine the other day, but when I went to run it it started throwing the error. I decided to take a break, and when I came back today it was still throwing the error. ... # Fatal error in v8::HandleScope::CreateHandle() # Cannot create a handle without a HandleScope Are you sure you don't have any Handles being statically initialized somewhere? Maybe in a DLL you are linking to? That could cause this. If you add a debug output line when you enter main(), is that line ever output before the crash? -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Re: Wrapping a C++ class, revisited
On Sat, Jul 20, 2013 at 3:45 PM, Richard S blakpi...@gmail.com wrote:
Hello. I've tried following along with this and the embedder's guide, but
my point binding only works to an extent. The constructor works, but for
some reason when I use an invalid constructor the object in JavaScript is
not undefined (I set the return value to be so).
The return value of a JS constructor is ignored - it is handled
automatically by the 'new' operator:
[stephan@host:~/]$ cat foo.js
function MyClass(){
return hi;
}
var x = new MyClass();
print(x instanceof MyClass);
[stephan@host:~/]$ js foo.js
true
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Re: [v8-users] Re: Wrapping a C++ class, revisited
On Sat, Jul 20, 2013 at 5:12 PM, Richard S blakpi...@gmail.com wrote: Okay, then is there a way to return an undefined object on an improper constructor? And I still have yet to solve the problem with values not being what they're supposed to be :/ To signal a bad constructor, throw a JS-side exception by calling v8::ThrowException(). -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Re: How to reinitialize v8 after v8::V8::Dispose();
On Fri, Jul 19, 2013 at 12:06 PM, Arseniy Pavlenko h0x...@gmail.com wrote: http://dpaste.com/hold/1310462/ - here small example Example sometime works, sometime crash What i am doing wrong? As Dmitry implied: you're relying on undefined behaviour. Don't do that. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Why doesn't v8::TryCatch catch exceptions thrown from C++?
On Wed, Jul 17, 2013 at 1:33 AM, Adam Klein ad...@chromium.org wrote: The subject says it all. I'm trying to wrap some code that uses the V8 API to throw exceptions (via v8::ThrowException()), and was expecting wrapping those calls in a v8::TryCatch to do this for me. But it seems they bypass my TryCatch (though with SetVerbose(true) they are at least reported to me). Is there something I can do to make the TryCatch completely swallow an exception? Why is v8 supposed to know what TYPES of exceptions you throw and how to convert them to JS exceptions? Some apps throw std::exception, some throw (my::Exception const ), some throw (SomeMFCType *), and some even through std::string. There is no 100% generic approach to that. It is easy to write wrappers which convert such exceptions: https://code.google.com/p/v8-juice/wiki/V8Convert_FunctionBinding#Converting_Native_Exceptions_to_JS but it would be impossible for v8 to do that itself because it lacks the type information. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Wrapping a C++ class, revisited
On Mon, Jul 8, 2013 at 6:45 PM, Lyndsey lyndseypad...@gmail.com wrote: Thank you Ben. I assume you mean something like what's being done herehttp://stackoverflow.com/questions/6696706/node-js-native-addon-destructor-of-wrapped-class-doesnt-run? I think the problem is that I'm not using node, and that would be needed to do the following, correct? point-Wrap(args.This()); //Where Wrap is available because the C++ Point class extends ObjectWrap (from node.h) I would like to do this in pure V8 without using node. Is that possible? Am I making things too difficult? Wrapping classes can be easily done without node but it gets really tedious really quickly. There are several frameworks out there which can simplify this. Here's one example (out of many) which demonstrates a generic approach: http://code.google.com/p/v8-juice/wiki/V8Convert_ClassCreator but that particular one was massively broken by recent v8 API changes, so i unfortunately cannot recommend it to you. Others on this list have authored such tools, many of which possibly still work since the (still ongoing) v8 overhaul started, and maybe one of them can suggest a generic solution for you. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Wrapping a C++ class, revisited
On Mon, Jul 8, 2013 at 7:07 PM, Ben Noordhuis i...@bnoordhuis.nl wrote: or may not work for you, YMMV. Node.js has the luxury of being allowed to assume that the executed JS code isn't hostile, unlike e.g. a browser. Well worded: isn't hostile rather than is safe ;) -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Re: Making v8::Persistent safe to use
On Fri , Jun 21, 2013 at 9:19 AM, Dan Carney dcar...@chromium.org wrote: The transition from Local to Handle won't happen for a while. It's more of a cleanup step after everything else is done, and there's no urgency since there shouldn't be any performance impact. Correction: there is no urgency for Chrome. There _are_ hundreds of projects out there based on v8 other than Chrome, and none of them can plan for fixing their code which are broken by this series of changes. The callback signature changes alone break almost every single line of v8-using code i've written (tens of thousands of them), and i am still undecided as to whether to spend several weeks of my time patching for or whether to simply drop by v8-related projects (i'm leaning strongly towards the latter). i'm getting too old to spend weeks patching every time a 3rd-party library pulls the rug out from under me (and this isn't the first time v8 has done it, though this is certainly the most invasive change so far). :( -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] How to achieve scope property injection in v8?
On Wed, Jun 12, 2013 at 1:10 PM, Andreas Rossberg rossb...@google.comwrote:
And what's wrong with replacing this by the following?
{
let out = ''
function write(s) { o.out += s; },
function writeln(s) { o.out += s + '\n'; }
let obj = { title: 'whatever', otherMetaData: … }
eval(script);
}
i'm not working in the browser, but in principal... i think this is a
direction i can try. i can simply generate and eval the code - that hadn't
occurred to me. Thanks for the idea! i'm not generally a big fan of
generating script code because at some point the escaping becomes more
trouble than it's worth, but i think for my limited use case this might be
a viable option which fulfills my original desires/requirements.
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Re: [v8-users] C++ lifetime management via shared_ptr and
On Wed, Jun 12, 2013 at 7:58 PM, Mike Moening mike.moen...@gmail.comwrote: Your specific problem is easily solved with ref-counted objects on the C++ side. I've done exactly this with your same use case. It works fine. Thanks for that tip :). Please lets move the problem forward in a positive manner. This is a problem that absolutely can and NEEDS to be solved. But it's not going to be at the v8 level. A few years back one of the v8 devs said (in a post on this list, but i have no link handy) that v8 does not gc at shutdown because (i'm paraphrasing), it negatively impacts Chrome's shutdown time. i think most of us will agree that shutting down cleanly is better than shutting down quickly, but JS was not really intended (it was pointed out in that thread or a similar one) to be used with types which require proper destructor calls to ensure proper behaviour of the system. So, that's a positive answer in the sense that i'm positive v8 will never guaranty such a feature. v8's only _real_ concern, as far as directly adapting to customer needs, is Chromium and friends. (That's based off of my own observations over my years on this list, and not a sentiment expressed directly from anyone working on v8 (more implied by various answers they've provided).) :/ -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] How to achieve scope property injection in v8?
On Tue, Jun 11, 2013 at 5:53 PM, Michael Schwartz myk...@gmail.com wrote:
with (o) {
Yeah, i was hoping to avoid the 'with'. i assume there is no
clean/portable/sane way to do this in JS, and to be honest the idea never
occurred to me until today while tinkering on my own pet scripting engine
(which, by an accident of design, can do this from either native or script
code, but whether that's a feature or a bug is debatable).
Thanks, Andreas and Michael, for the responses.
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Re: [v8-users] How to access string of HandleString?
On Thu, Jun 6, 2013 at 5:20 PM, Bodo Kaiser i...@bodokaiser.io wrote: I am trying to get a const char * string out of a v8 String Object. Unfortunately all access result in a segmentation fault: Try: (i'm working from memory, but i _think_ this is right: v8::Utf8Value str( *yourStringHandle ); puts( *str ); -GetExternalAsciiStringResource()-length()); external strings are a special case of strings which are allocated elsewhere (outside of v8), or at least that's my understanding. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] C++ lifetime management via shared_ptr and
On Fri, May 24, 2013 at 1:53 AM, loudersp...@gmail.com wrote:
virtual ~Point()
{
assert(false); // Never called!
}
v8 does not guaranty that it will _ever_ call your destructors. It does
_not_ clean up automatically when it shuts down. This of course makes life
difficult for types which require proper closing or close ordering (e.g.,
db statements and their drivers), but v8 is really centered on types which
can be thrown away without running a destructor.
v8::V8::Initialize(); // Initialize v8. (Is this needed?? If so, why
isn't it mentioned here - https://developers.google.com/v8/embed)
i've been using v8 since 2008 and never seen/used it.
v8::V8::LowMemoryNotification(); // I saw this mentioned as a way to
force GC, but it doesn't help. Even so, I would think v8::V8::Dispose
would clear all garbage.
v8::V8::Dispose(); // Initialize v8. (Is this needed?? If so, why
isn't it mentioned here - https://developers.google.com/v8/embed)
Whether or not it is needed, i don't know (i don't remember consistently
using it). It won't, however, guaranty to run any cleanup of your bound
types. In order for you to start seeing your dtor running, you need to
create many thousands of them before v8 will start cleaning them up. In
short-lived test apps the dtors are rarely run. In all of my bound native
types i tend to bind a destroy() method which manually triggers the
destruction process. Here's an example of how to do that:
https://code.google.com/p/v8-juice/source/browse/convert/include/cvv8/ClassCreator.hpp#980
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Re: [v8-users] C++ lifetime management via shared_ptr and
On Fri, May 24, 2013 at 9:58 PM, Jim Acquavella loudersp...@gmail.comwrote: Thanks Stephan! I'm surprised and disappointed I can't guarentee my C++ objects will be destroyed. Can anyone from Google comment on this? There must be a way to force everything allocated to be released at shutdown, no?! That horse has been beat to death here a few times already. No - there is no guaranty that v8 will ever call your dtors and (AFAIR) no 100% reliable way to force it to. To be safe, bind a destructor function to your native types. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] How to test an Argument for InstanceOf() type
On Wed, Apr 24, 2013 at 11:00 AM, Ben Noordhuis i...@bnoordhuis.nl wrote: ...The trick I mentioned in my other post is that you add a second internal field that points to some atom (usually a char class_name_id[] = MyClassName) that you check for in your prototype methods so you can be sure that args.This() is what you expect it to be. Be sure to check args.This()-InternalFieldCount() as well. Another option, as opposed to using a string, is take the address of some internal static value. The value and type of that pointer is largely irrelevant - it's _address_ can be used as the type identifier. In cvv8 we use a mixture: we use the address of a static string (not its value) defined in a template, since comparing the address is much faster than doing a strcmp and the address is guaranteed to be unique within the app's address space. We don't use that trick in node.js actually but that's because native objects are not exposed directly, there's (almost) always some pure JS object sitting in front of it. It's a pretty good approach when you're not operating in a hostile environment (running untrusted code), it saves a lot of headaches. Here's an example where it is important to have such a type-safety net: Assume Foo and Bar are both client-define native types: var x = new Foo(); var y = new Bar(); x.doBar = y.doBar; x.doBar(); // doBar expects that 'this' is-a (Bar*) -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] How to test an Argument for InstanceOf() type
On Wed, Apr 24, 2013 at 1:18 PM, Ben Noordhuis i...@bnoordhuis.nl wrote: That's not another option - that's the same option. :-) Yeah, technically. My point was only that it could some opaque pointer, e.g.: static int foo = 3; and pass a pointer to that. But yes, having it be a string makes debuggering easier. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] callback Function Call receiver argument
The receiver is the this object you want to use (it is not optional). For
your case the global obj or even the callback itself probably suffice.
- stephan beal
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On Apr 16, 2013 11:24 PM, Mike Moening mike.moen...@gmail.com wrote:
I'm trying to do a simple callback into a JS script.
The script does something like this:
function OnProgress(percent) {
//Do something
}
myObj-setProgressCallback(OnProgress); //Tell it how to call us back...
My native C++ code stores the function passed to setProgressCallback in a
PersistentFunction then proceeds to call it later when appropriate.
The call is performed like this:
HandleValue argv[1];
argv[0] = v8::Number::New(100);
TryCatch try_catch;
HandleValue result = myStuff-m_fnProgressCallack-Call(???, 1, argv);
What is the 1st parameter to the Call() method supposed to take?
What is the receiver object?
Passing in an empty handle breaks it. If I pass in the function itself I
get this error:
called_non_callable
What is the secret?
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[v8-users] Re: Force GC
Short answer is: v8 does not guarantee that weak ptr callbacks will EVER be called. Yes, this is painful, but even if such a guarantee could be made, there's no way for v8 to know the proper destruction order (important, e.g., for db handles and prepared statements). My tip is: add a destroy() method to your bound classes and clean up manually. try/finally blocks are helpful here. (sent from a mobile device - please excuse brevity, typos, and top-posting) - stephan beal http://wanderinghorse.net On Apr 15, 2013 8:03 PM, Mike Moening mi...@reteksolutions.com wrote: I’ve been trying to figure out a way to force GC for V8. ** ** Read about and tried the AdjustAmountOfExternalAllocatedMemory() and IdleNotification() methods. I tried AdjustAmountOfExternalAllocatedMemory(1024*1024*100); //100 MB should be enough! ** ** Upon shutdown of my application (and periodically too) it is crucial that my MakeWeak() IsNearDeath destructor callbacks get fired to properly cleanup file handles and C++ memory. ** ** How can I do this? At least with spidermonkey JS_GC() you would force it! ** ** I’m using memory diagnostics tools that report false leaks since GC isn’t fired… ** ** Mike Moening ** ** *Retail Technology Solutions Inc.* 23235 Texas Avenue Suite 125 Lakeville, MN 55044 direct: 952-461-3770 ** ** -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Is it valid to not close a scope?
On Sun, Apr 14, 2013 at 5:30 PM, bodo.kai...@enabre.com wrote:
Hello,
I want to use a function which acts as internal exception shortcut
unfortunately I cannot pass the current scope so I would create a new one.
Is this whole strategy valid? If not how would it look right?
My understanding, based on previous discussions on this list, is that a
HandleScope is not needed at all if the code in question is being called
from JS space (because such a call has an implicit HandleScope around it).
Based on my own experience, your InvocationCallback and exception-thrower
look perfectly koster to me, but i would drop both of the HandleScopes -
IMO they are not needed because your InvocationCallback will be called from
JS-space in response to a Function call, and such calls have an implicit
Scope provided by the engine.
HandleValue SomeMethod(const Arguments args) {
HandleScope scope:
if (!args[0]-IsObject() || args[0]-IsArray())
if i'm not mistaken (and i might be), IsObject() will(???) also return true
for an Array because an Array is-a Object.
return ThrowTypeError(Argument must be a object literal.);
return scope.Close(args[0]-ToObject());
};
NODE_MODULE(test, init);
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Re: [v8-users] Is it valid to not close a scope?
On Sun, Apr 14, 2013 at 5:51 PM, Bodo Kaiser bodo.kai...@enabre.com wrote: I require scope.Close() to return a value That's a common misconception. i've been using v8 for 4+ years now and i _never_ use HandleScopes (and can return values just fine). A HandleScope, from what i can gather, is just a hint to the GC to help clean up temporary/local-only values. . My sorrow is that I could get problems with GC because I did not close the scope or something. But you do not confirm these sorrows? When you call a function from JS: myFunction() and that then calls your C++ InvocationCallback, there is an implicit scope being created in the call, so there is no need to create an extra one in your app (unless you are calling the code from C++ without first going through the JS engine, but such cases are rare in practice). To the second: Yes that is why there is args[0]-IsArray() That's my point: IsArray() is useless here because the order of operations ensure that IsObject() will always trump IsArray(). i.e. if it's an array then IsObject() will return true and the IsArray() call is not needed (it will never actually be called due to the short-circuiting logic of the OR operator). (NOTE, however, that i am ASSUMING (without having tested), that IsObject() will indeed return true for a Function or Array Object. The API docs are not clear on this distinction.) -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Is it valid to not close a scope?
On Sun, Apr 14, 2013 at 6:06 PM, Bodo Kaiser bodo.kai...@enabre.com wrote: I think you oversaw the ! (so !obj-IsObject()). OR will stop on the first true else it will go through each expression. !obj-IsObject() will so filter the primitive values else I agree :) Doh, you're absolutely right. Mae culpa! Regarding: obj-Get(String::New(key)); Now, i don't know a shortcut for that. :( -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] write to a txt file (S.O. Windows)
JS has _no_ i/o function (and neither does v8, since it only implements core JS). To write anything to anywhere with v8 you'll need to add your own function to do so. See the sample shell for examples. On Sat, Apr 6, 2013 at 5:18 PM, Paolo Pellegrini pellegrinip...@gmail.comwrote: I would like to write to a text file using javascript V8. my operating system is Windows!, how can I do? -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] How can I bind functions on the fly?
On Mon, Apr 1, 2013 at 3:20 PM, danijar pfis...@gmail.com wrote: But is there a way to bind C++ functions to an already created context at runtime? Or maybe it is possible to recreate the context and adopt the state of the old context to a new one? If i understand your question correctly, you simply need to add them to your 'globals' object. You can get the global object later (without a direct reference) with Context::GetCurrent()-Global(). -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Why is there an access violation in this minimal example?
On Mon, Apr 1, 2013 at 3:15 PM, danijar pfis...@gmail.com wrote:
v8::Isolate* isolate = v8::Isolate::GetCurrent();
...
v8::InvocationCallback* function =
Function.targetv8::InvocationCallback();
v8::Isolate* isolate = context-GetIsolate();
...v8::Isolate* isolate = context-GetIsolate();
The error is a null-pointer exception. Are you 100% certain that the above
calls return non-NULL?
v8::HandleScope handle_scope(args.GetIsolate());
if (first) first = false;
else printf( );
v8::String::Utf8Value str(args[i]);
const char* cstr = *str ? *str : string conversion failed;
printf(%s, cstr);
FWIW, using printf() for this purpose is way overkill (go look at the
internals of any printf() impl for why)., The first printf() can be
replaced by putchar(' ') and the second one with puts() (which adds a
newline to the end). i know this is a pedantic detail, and is not really
relevant for example code, but the problem is that people tend to
copy/paste example code for use in real programs, under the assumption that
the example code shows best practices (using printf() when one of its more
efficient counterparts will suffice is not best practice).
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Re: [v8-users] Why is there an access violation in this minimal example?
On Mon, Apr 1, 2013 at 4:57 PM, danijar pfis...@gmail.com wrote: It crashes at context-Global(); because of access violation as before. I also tried to access the context using v8::Context::GetCurrent()-Global() but the result is the same. i remember having a similar problem long ago (2+ years), where Context::GetCurrent() was returning NULL, but i unfortunately don't remember (A) what caused it or (B) what solved it for me :/. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Re: Segmentation fault
On Wed, Mar 20, 2013 at 10:50 AM, Егор Яковлев goga@gmail.com wrote: I am really stupid. I forgot to return the value of the function serverSendRequest. Can i do this function void? To emulate a void return in v8, simply return v8::Undefined(), which is a shared Value instance. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] compiling process of scripts
On Fri, Mar 8, 2013 at 10:37 AM, sc scha...@gmail.com wrote:
i have a very general question about the compiling process of javascript
scripts via v8.(maybe the question is too broad)
i'm currently trying to modify the compiler::compile function in
compiler.cc so that it hijacks the source code adds very simple prints
after every row in the source code and returns
this as the new source to compile
You do understand that that's doomed to failure, right? Consider this code
and where you print/debugging statements would be injected:
for( var i;
i 12;
++i )
{
}
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Re: [v8-users] Simple way of running html embedded js
On Thu, Mar 7, 2013 at 5:30 PM, Sandor Hadas sourcesamp...@gmail.comwrote: So my question is: What is the simplest way (without depending on another big library like v8-juice) to define the object model? Something really-really-really simple... There is no simple/trivial way to do it. The DOM is specified by a different standard than the core JS language (a basic fact the vast majority of JS literature never mentions, i grumblingly add) and implementing it implies a great deal of effort. (Even with the help of v8-juice, vu8, v8-convert, silkjs, etc., it's still far from trivial.) I guess there are some people who did this already since that looks a fairly basic use of V8. At some point there was an effort, started by John Resig (of jQuery fame), based on the Rhino JS engine, called env.js (currently at http://www.envjs.com). env.js implemented _much_ (but not all) of the DOM API in JS, meaning it could be used in headless JS engines (like Rhino (John's original target platform) and v8). Last i checked (a couple of years ago) it was still missing some of the more interesting functionality, like setTimeout() and XHR (both of which require some degree of native-code-level support). -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Re: Simple way of running html embedded js
On Thu, Mar 7, 2013 at 9:36 PM, Sandor Hadas sourcesamp...@gmail.comwrote: 4) It runs javascript in its black (gray) box and removes all javascript; it replaces those with actual generated html code, so only html resides with no javascript script nodes inside This behaviour does not at all describe how HTML/DOM processors work, so... Am I the first person looking for something like this? i suspect the answer is yes. The fact that a script can access the DOM immediate gives it access to elements of a page far outside of the spot where the SCRIPT tag lives, and it can change those elements many times during the duration of a script. The concept of replacing a SCRIPT tag with its generated output is not new in and of itself (there are non-JS tools specifically for doing that[1]) but does not at all describe how JS and the related DOM APIs work. [1] the Fossil SCM (http://fossil-scm.org) includes a very basic script processor which does that, and that is used to add (minor) level of server-side dynamics to many of its generated pages. There is a standalone release/fork of that processor here: http://fossil.wanderinghorse.net/repos/th1-sgb/ -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] [v8 library as so]
On Wed, Feb 27, 2013 at 8:06 AM, nagarjuna atluri nagajun...@gmail.comwrote: Thanks for the info, but both the methods does not generate shared library for v8 in gyp build system, can any one help me out... What exactly are the symptoms? Errors or simply no .so's? If the build runs but no SOs are generated - i had a similar (completely unexplainable) problem on one particular version of Ubuntu. The build ran without errors but the generated SOs were completely empty (not size 0, but also no C symbols). i _think_ it was 11.04 or 11.10, but i don't recall with certainty. i do remember that after moving away from that installation (first to another Linux distro, then back to a newer Ubuntu) the problem disappeared. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Segmentation fault when creating new v8 context.
On Thu, Feb 21, 2013 at 3:44 PM, Sven Panne svenpa...@chromium.org wrote: I don't even know what to compile from https://code.google.com/p/v8-juice/source/browse/, the trunk seems to be out of date, it uses e.g. GetPointerFromInternalField and friends which are not part of v8's external API anymore. The main project tree there is historical and no longer maintained. Only the /convert directory (the one i sent the links to) is current vis-a-vis v8's API (or was, until 2 days ago), and we removed GetPointerFromInternalField() from it over the holidays because its deprecation/behaviour change broke our class-binding mechanism. Note that we are really willing to help embedders, but digging through someone else's code with only vague hints is a huge waste of time. As is digging through v8 to find what v8 changes broke our (unchanged) code. So nobody wins. While trying to create a reproducible test case for you, i found 2 things: a) the Hello World example in the v8 docs no longer compile due to API changes. https://developers.google.com/v8/get_started b) the assertion problem has magically disappeared in the meantime (using r13713). Another hint: The external v8 API is undergoing some changes, mainly making the use of an Isolate explicit and mandatory Where can we find documentation on how to do this? i'm currently looking over the v8 docs (https://developers.google.com/v8/) and i see neither hide nor hair of Isolates. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] GetPointerFromInternalField deprecated?
On Fri, Feb 22, 2013 at 11:26 PM, Flying Jester foolkingcr...@gmail.comwrote: This obviously doesn't work with a 1 to 1 replacement with the aligned version of the function. Welcome to the club :). What i ended up doing (because the Aligned version kept inexplicably asserting when given pointers allocated with (new T)), was to use an explicit v8::External wrapper to hold my pointer and replacing the PointerTo/FromInternalField calls with the normal InternalFields calls. Example usages: set: https://code.google.com/p/v8-juice/source/browse/convert/include/cvv8/ClassCreator.hpp#776 get: https://code.google.com/p/v8-juice/source/browse/convert/include/cvv8/ClassCreator.hpp#603 -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Segmentation fault when creating new v8 context.
On Wed, Feb 20, 2013 at 4:34 PM, Егор Яковлев goga@gmail.com wrote: I have the same problem. I built v8 for x64 architecture on Ubuntu 12.04 using gyp. And now i try to run the Hello World example. But i have Segmentation fault (core dumped). This error occurs when creating new v8 context. Same here, using: [stephan@host:~/src/google/v8]$ svn info Path: . URL: http://v8.googlecode.com/svn/trunk Repository Root: http://v8.googlecode.com/svn Repository UUID: ce2b1a6d-e550-0410-aec6-3dcde31c8c00 Revision: 13700 Node Kind: directory Schedule: normal Last Changed Author: yang...@chromium.org Last Changed Rev: 13692 Last Changed Date: 2013-02-19 14:55:47 +0100 (Tue, 19 Feb 2013) Ubuntu 12.04 on x64, gcc 4.6.3. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Segmentation fault when creating new v8 context.
On Thu, Feb 21, 2013 at 9:54 AM, Stephan Beal sgb...@googlemail.com wrote: On Wed, Feb 20, 2013 at 4:34 PM, Егор Яковлев goga@gmail.com wrote: I have the same problem. I built v8 for x64 architecture on Ubuntu 12.04 using gyp. And now i try to run the Hello World example. But i have Segmentation fault (core dumped). This error occurs when creating new v8 context. Same here, using: [stephan@host:~/src/google/v8]$ svn info Path: . URL: http://v8.googlecode.com/svn/trunk Repository Root: http://v8.googlecode.com/svn Repository UUID: ce2b1a6d-e550-0410-aec6-3dcde31c8c00 And on the bleeding edge: [stephan@host:~/src/google/v8]$ svn info Path: . URL: http://v8.googlecode.com/svn/branches/bleeding_edge Repository Root: http://v8.googlecode.com/svn Repository UUID: ce2b1a6d-e550-0410-aec6-3dcde31c8c00 Revision: 13700 Node Kind: directory Schedule: normal Last Changed Author: yang...@chromium.org Last Changed Rev: 13700 Last Changed Date: 2013-02-20 15:29:40 +0100 (Wed, 20 Feb 2013) -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Segmentation fault when creating new v8 context.
On Thu, Feb 21, 2013 at 9:54 AM, Stephan Beal sgb...@googlemail.com wrote:
Same here, using:
[stephan@host:~/src/google/v8]$ svn info
Path: .
URL: http://v8.googlecode.com/svn/trunk
Repository Root: http://v8.googlecode.com/svn
Repository UUID: ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Revision: 13700
i've been able to narrow this down to being introduced somewhere between:
-r{20130215T00Z} (OK)
and
-r{20130220T00Z} (Not OK)
but my boss (who wants me doing something completely different) is losing
patience with me, so i won't be able to investigate it further.
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Re: [v8-users] Segmentation fault when creating new v8 context.
On Thu, Feb 21, 2013 at 11:39 AM, Stephan Beal sgb...@googlemail.comwrote:
i've been able to narrow this down to being introduced somewhere between:
-r{20130215T00Z} (OK)
and
-r{20130220T00Z} (Not OK)
One more...
-r{20130218T00Z}
does not exhibit this problem.
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Re: [v8-users] Segmentation fault when creating new v8 context.
On Thu, Feb 21, 2013 at 12:42 PM, Sven Panne svenpa...@chromium.org wrote:
What are the detailed steps to reproduce this?
- Update to the latest version
- rebuild any custom v8 client app of your choice which has worked for the
past year or more.
- start that app
- crash at startup:
#
# Fatal error in ../src/v8threads.cc, line 53
# CHECK(isolate != __null) failed
#
C stack trace ===
1: V8_Fatal
2: v8::Locker::Initialize(v8::Isolate*)
3: v8::Locker::Locker(v8::Isolate*)
4: ??
5: ??
6: ??
7: ??
8: __libc_start_main
9: ??
All of my v8 apps crash at startup with the current trunk v8. The last
working versions i was able to test was -r{20130218T00Z}, which
resolves to -r13679.
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Re: [v8-users] Segmentation fault when creating new v8 context.
On Thu, Feb 21, 2013 at 2:03 PM, Sven Panne svenpa...@chromium.org wrote:
OK, my apps are d8 and Chrome, and both work. :-) Seriously, we need more
detailed steps and not just some fuzzy prose. It could
i understand that, but you cannot expect us to go decompose our apps every
time new v8 behaviour breaks something as basic as application startup
(this isn't the first time in the past 6 months my apps start mysteriously
breaking due to mysterious v8 changes). Here's what i know, without going
so far as to write a new app which demonstrates this problem (i have
several which demonstrate it already)...
-r{20130218T00Z} works for me
-r{20130220T00Z} does not work for me
very well be the case that some applications embedding v8 worked only by
accident, so a stand-alone reproduction is really needed, e.g. a single
small C/C++ file embedding v8 which crashes for you when compiled and run.
The apps i have which break with the newer versions have worked for 18+
months without any modifications on my side. If they only worked by
accident then something is horribly wrong with v8 (because my apps are all
modeled after the shell example app and the sparse documentation from the
v8 team). None of my apps are extremely trivial, so i have no trivial
example. All of them use the same startup process, however, and that is
where v8 is failing for several of us. Here's an example which crashes:
https://code.google.com/p/v8-juice/source/browse/convert/addons/shell-skel/shell.cpp#65
during initialization, which happens here:
https://code.google.com/p/v8-juice/source/browse/convert/include/cvv8/V8Shell.hpp#175
the part which craps out is the v8::Locker constructor, which is literally
the first value initialized in my app after main() is entered, before any
of my app-specific code gets run. The crash dump and backtrace look like:
[stephan@host:~/cvs/v8-juice/convert/addons/shell-skel]$ gdb --args ./shell
test.js
GNU gdb (Ubuntu/Linaro 7.4-2012.04-0ubuntu2.1) 7.4-2012.04
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later http://gnu.org/licenses/gpl.html
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type show copying
and show warranty for details.
This GDB was configured as x86_64-linux-gnu.
For bug reporting instructions, please see:
http://bugs.launchpad.net/gdb-linaro/...
Reading symbols from
/home/stephan/cvs/v8-juice/convert/addons/shell-skel/shell...done.
(gdb) r
Starting program:
/home/stephan/cvs/v8-juice/convert/addons/shell-skel/shell test.js
[Thread debugging using libthread_db enabled]
Using host libthread_db library /lib/x86_64-linux-gnu/libthread_db.so.1.
#
# Fatal error in ../src/v8threads.cc, line 53
# CHECK(isolate != __null) failed
#
C stack trace ===
1: V8_Fatal
2: v8::Locker::Initialize(v8::Isolate*)
3: v8::Locker::Locker(v8::Isolate*)
4: ??
5: ??
6: ??
7: ??
8: __libc_start_main
9: ??
JS stack trace is not available ===
Isolate for the thread is not initialized =
Program received signal SIGTRAP, Trace/breakpoint trap.
v8::internal::OS::DebugBreak () at ../src/platform-linux.cc:427
warning: Source file is more recent than executable.
427 #elif defined(__mips__)
(gdb) bt
#0 v8::internal::OS::DebugBreak () at ../src/platform-linux.cc:427
#1 0x776fcfff in v8::internal::OS::Abort () at
../src/platform-linux.cc:409
#2 0x7732281e in V8_Fatal (file=0x7779e749
../src/v8threads.cc, line=53, format=0x7779e45e CHECK(%s) failed)
at ../src/checks.cc:59
#3 0x7761f569 in v8::Locker::Initialize (this=0x7fffe160,
isolate=0x0) at ../src/v8threads.cc:53
#4 0x7734e5ff in v8::Locker::Locker (this=0x7fffe160,
isolate=0x0) at ../src/../include/v8.h:4003
#5 0x00404c99 in cvv8::Detail::V8MaybeLockertrue::V8MaybeLocker
(this=0x7fffe160) at ../../include/cvv8/V8Shell.hpp:33
#6 0x00404555 in cvv8::V8Shelltrue::V8Shell
(this=0x7fffe160, globalObjectName=0x0, argc=2, argv=0x7fffe338,
argOffset=1) at ../../include/cvv8/V8Shell.hpp:181
#7 0x00403c7c in v8_main (argc=2, argv=0x7fffe338) at
shell.cpp:65
#8 0x00403f7b in main (argc=2, argv=0x7fffe338) at
shell.cpp:136
The problem is obviously the NULL Isolate. My v8 client code has _never_
(in the 4-some-odd years i've been using v8) explicitly used an Isolate, so
i find the it worked by accident hypothesis hard to swallow.
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Re: [v8-users] NewInstance failing
On Thu, Feb 14, 2013 at 6:01 PM, Greg Martin g...@softsprocket.com wrote: I've tried preceding the call with a TryCatch but it still terminates. I don't know why and don't know how to find out why. That sounds suspiciously like a v8-internal assertion is being triggered. If that is the case - link against a debug build of v8 and it will dump tons of info to stderr when an assertion is triggered (quite often explaining exactly what when wrong and where it happened). A non-debug build silently dies in such a case. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups v8-users group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [v8-users] Passing handles by value
On Wed, Nov 14, 2012 at 1:30 PM, Jakob Kummerow jkumme...@chromium.orgwrote: Handles are essentially pointers to pointers. The indirection is necessary because the target object might be moved around by the GC. There is no need to pass handles by reference, because passing the handle by value is just as efficient. Note that passing the *handle* by value does not mean that the *object* that the handle points to is passed by value -- think of it as passing the object by handle, which is the GC-safe way of passing the object by reference. To expand on that just a tiny bit: when passing handles by const reference it is still possible to call non-const methods of the referenced Value/Object because the Value it points to is not const (only the handle reference is const). -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Help with setting local js variable to Null()
On Mon, Jan 21, 2013 at 1:53 PM, ioannis ioanni...@gmail.com wrote: // (2) If args[0] is a global object then remove the object form global scope LocalObject global = self-CreationContext()-Global(); This part is not necessary. You already do: // (3) Delete the c++ object and call its destructors delete p; // (4) SetInternalField to null self-SetInternalField(0, Null()); which will (if your binding code takes some care) avoid the case that a client steps on a now-invalid native (or a _different_ native which was reallocated at the same address). But to answer your question: i can't. i don't think there is a way to do that. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] [v8 library as so]
On Thu, Jan 17, 2013 at 4:45 PM, nagarjuna atluri nagajun...@gmail.comwrote: Can any one please let me know the procedure to build V8 as shared library in gyp build system. Basically i m having chrome browser code. https://code.google.com/p/v8/wiki/BuildingWithGYP -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] [v8 library as so]
On Thu, Jan 17, 2013 at 5:00 PM, nagarjuna atluri nagajun...@gmail.comwrote: Thanks for the reply but wanted to know in which gyp file we have to set the options There are no file-level options to set - it's all command-line driven. Running it as documented at that wiki page will build a .so file. (Note that there is no support for building a static library, at least on Linux.) -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] How can I convert a argument to v8::Array?
On Tue, Jan 15, 2013 at 3:16 AM, amourfou amourfo...@gmail.com wrote:
In the following source codes, if args[0] is array object, let me know how
to convert it to v8::Array or handle it.
... if (args[0]-IsArray() == true)
{
HandleArray ar( Array::Cast(args[0]) );
}
}
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Re: [v8-users] V8 build on Linux using GYP
On Thu, Jan 10, 2013 at 5:44 AM, Neha nehatripathi28...@gmail.com wrote: I tried strictaliasing=off option along with make native. This worked. The code got compiled with this option. What are the implications of using this option when i want to further use V8 with my application? If you mean as a normal client, just using the v8 public API, this option doesn't affect the client code or how the client code needs to be compiled, it only affects how gcc compiles v8. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Build statically linked v8 shell?
On Thu, Jan 10, 2013 at 7:58 AM, Joe Millenbach jmillenb...@gmail.comwrote: If I make a patch that added the option, could it be accepted? Or is this functionality that is not desired? FWIW: v8 uses networking classes in some of the debugging code, and on Linux the networking libraries cannot be linked statically (for voodoo reasons which i don't recall). This ticket suggests that one might also have problems when statically linking against pthreads on linux: http://sourceware.org/bugzilla/show_bug.cgi?id=10652 -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Build statically linked v8 shell?
On Thu, Jan 10, 2013 at 10:37 PM, Joe Millenbach jmillenb...@gmail.comwrote: platform-posix.cc:(.text._ZN2v88internal11POSIXSocket7ConnectEPKcS3_+0x8d): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking That's the networking libraries problem i vaguely mentioned above. You _can_ link statically to them but it won't be a true static link - at runtime the app will still (perhaps indirectly) need the networking DLL(s). When static linking of v8 broke for me (way back when) due to this problem i thought, WTF are they using networking code for? It turns out that it's only used in the debugger (or was at the time). Maybe (not sure) it's possible to build without that component, and therefore without the networking requirement. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Re: SetAlignedPointerInInternalField() assertion
On Thu, Jan 3, 2013 at 11:54 AM, Sven Panne svenpa...@chromium.org wrote: Could you give detailed steps to reproduce your problem? Have you checked that the pointer in question at the point of the assertion is *really* aligned (i.e. has 0 as its last bit)? Hi, Detailed steps to reproduce the problem require a huge amount of underlying library code, which wouldn't be all that helpful for you :/. i have in the mean time worked around the problem altogether by using SetInternalField(n, External::New(...)) instead of SetPointerInInternalField() (which i _thought_ was just a thin wrapper around the former, but is apparently not). i have only verified that the pointers are *really* aligned in the sense that my man pages say: The malloc() and calloc() functions return a pointer to the allocated memory that is suitably aligned for any kind of variable. i can't ever in my life remember having seen a malloc'd address which is _not_ an even number. If the system allocator is not returning aligned memory then i'm probably screwed anyway, so i still suspect a problem/mis-assumption in v8 here (because all of my memory is coming from the standard allocators resp. (new T)). That said, using External::New directly works perfectly fine for what i'm doing, so i don't need any specific alignment requirements. Switching to External also incidentally fixed a regression i was experiencing involving accessing internal fields post-destruction (after WeakPtr cleanup), where Object values would suddenly assert with is not an Object in certain contexts. It seems that that problem (reported in another post on the same day) was a side-effect of the alignment-related changes resp. my use of SetPointerIn...() in conjunction with those changes. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
[v8-users] Re: SetAlignedPointerInInternalField() assertion
On Sat, Dec 22, 2012 at 2:00 PM, Stephan Beal sgb...@googlemail.com wrote: # # Fatal error in v8::Object::SetAlignedPointerInInternalField() # Pointer is not aligned # Is there a known problem for x64 with these routines or is there another replacement we should be using instead of the deprecated SetPointerInInternalField()? gcc 4.6.3 on Ubuntu 12.04, Linux 3.2.0 on x64. v8 trunk r13274. i can confirm that this is also happening in a 32-bit VM with the same OS/compiler, hosted on the above 64-bit system, but a colleague reports that it is not happening on his Windows (32-bit) box. The only pointers i am using as internal fields are allocated either on the stack or via the system allocator, so i would certainly expect them to be aligned properly. Using Get/SetPointerInInternalField() works flawlessly as before but break my normal build process because i use -Werror and they are marked as deprecated. Any pointers (as it were) would be appreciated. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
[v8-users] SetAlignedPointerInInternalField() assertion
Hello, v8 devs, after several months of being offline i'm coming back into the world and a colleague pointed out this change to me: https://code.google.com/p/v8/source/detail?r=12849path=/branches/bleeding_edge/include/v8.h Summary: Added highly efficient Object::SetAlignedPointerInInternalField and Object::GetAlignedPointerFromInternalField functions for 2-byte-aligned pointers. Their non-aligned counterparts Object::GetPointerFromInternalField and Object::SetPointerInInternalField are now deprecated utility functions. So we did a drop-in replace of those routines with their new equivalents and now get (on x64, but not i32) alignment assertions on objects created using the system allocator (new T). demo.cpp:199:MyType(): MyType::MyType() @ 0x1fba880 # # Fatal error in v8::Object::SetAlignedPointerInInternalField() # Pointer is not aligned # Is there a known problem for x64 with these routines or is there another replacement we should be using instead of the deprecated SetPointerInInternalField()? gcc 4.6.3 on Ubuntu 12.04, Linux 3.2.0 on x64. v8 trunk r13274. :-? -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
[v8-users] Painful regression in Object destruction behaviour
Hi, devs,
i have just found a regression (from sometime since last summer) in the
handling of Object destruction. Consider this JS code:
assert(m.destroy(), 'm.destroy()');
assertThrows( function() {m.doFoo();} );
(m is a bound Native object)
m.destroy() simply triggers the WeakPtr destructor callback and Dispose()s
the handle. What USED to happen after that was that any method calls could
still be made on m (like the call to m.doFoo() above) but my framework
would see that the Native binding in that Object (i.e. an Internal Field)
was missing and would trigger a JS-side exception. What now happens is that
the call to m.doFoo() triggers a v8 assertion as a side-effect of my code
trying to figure out of m still points to a valid native. So m.doFoo() now
results in the following assertion:
ConvertDemo.hpp:246:~BoundSubNative(): @0x1a47880 is destructing
ConvertDemo.hpp:53:~BoundNative(): @0x1a47880 is destructing.
Assertion OK: m.destroy()
#
# Fatal error in ../src/objects-inl.h, line 2386
# CHECK(object-IsJSObject()) failed
#
C stack trace ===
1: V8_Fatal
2: v8::internal::JSObject::cast(v8::internal::Object*)
3: ??
4: v8::Object::GetPointerFromInternalField(int)
5: ??
6: ??
7: ??
8: ??
9: cvv8::Detail::MethodToInCaVoidBoundNative, void (),
(BoundNative::doFoo()), true::Call(v8::Arguments const)
10: ??
11: ??
12: ??
13: ??
i don't know if this change was intentional but it hoses an inordinate
amount of my code which assert()s that my framework can correctly avoid
stepping on a deallocated native pointer (after the WeakPtr destruction
callback is called on it). It also makes it painfully simple to crash the
native app from script code, the avoidance of which is the whole purpose of
my framework catching post-destruction access to deallocated natives.
(Yes, i know that GetPointerFromInternalField() is deprecated but
GetAlignedPointerFromInternalField() asserts with not-aligned errors on
x64!)
Is this a bug or a feature which i need to go rewire my code to deal with?
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[v8-users] Re: Painful regression in Object destruction behaviour
On Sat, Dec 22, 2012 at 2:27 PM, Stephan Beal sgb...@googlemail.com wrote:
Hi, devs,
i have just found a regression (from sometime since last summer) in the
handling of Object destruction. Consider this JS code:
...
# Fatal error in ../src/objects-inl.h, line 2386
# CHECK(object-IsJSObject()) failed
#
The worst part is that i verify that Value-IsObject() before attempting
the GetPointerFromInternalField():
ResultType operator()( v8::Handlev8::Value const h ) const
{
if( h.IsEmpty() || ! h-IsObject() ) return NULL;
else
{
void * ext = NULL;
v8::Handlev8::Value proto(h);
while( !ext !proto.IsEmpty() proto-IsObject() )
{
v8::Localv8::Object const obj( v8::Object::Cast(
*proto ) );
ext = (obj-InternalFieldCount() != InternalFieldCount)
? NULL
: obj-GetPointerFromInternalField(
InternalFieldIndex );
if( ! ext )
{
if( !SearchPrototypeChain ) break;
else proto = obj-GetPrototype();
}
}
return ext ? static_castResultType(ext) : NULL;
}
}
so this appears to be a genuine bug in v8, in that IsObject() is returning
true, Object::Cast() is functioning (not asserting), but
GetPointerFromInternalField() is triggering a not-an-object assertion.
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Re: [v8-users] [Beginner question] How to link a plugin
On Fri, Sep 28, 2012 at 7:07 AM, Moritz Willig moritz.wil...@gmail.comwrote: i know NodeJS and have already build some Projects with it. But I want to learn how to solve this problem this in general. As far as i see does NodeJS also provide Plugins but they have to be linked statically into the program (or have to be written in JS itself). FWIW: there is no in general solution to this problem from a v8 perspective because v8 does not define any sort of native-side plugin interface and the behaviour of DLLs is unspecified by the C++ standard. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] [Beginner question] How to link a plugin
On Fri, Sep 28, 2012 at 2:36 PM, Michael Schwartz myk...@gmail.com wrote: The problem is you have v8 as a static library. It needs to be a shared one and the shared library (testplugin) needs to be linked against libv8.so and every other library it calls. See this for an example build script: https://github.com/mschwartz/SilkJS-redis/blob/master/build.js And here's an article which covers some of the details in a project-agnostic manner: http://wanderinghorse.net/computing/papers/#classloading_cpp -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] [Beginner question] How to link a plugin
On Fri, Sep 28, 2012 at 3:39 PM, Michael Schwartz myk...@gmail.com wrote: I didn't see anything useful at the link. It explains, for example, why static libs are sometimes problematic in conjunction with C++ templates and plugins (because unreferenced symbols do not get linked in to the client). The issue is you have a .so that's getting loaded via dlopen(). That .so needs to call functions in the v8 library that is statically linked into the main program. For example. And if those do not get referenced from client code then they don't (or might not) get linked in. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Is there any way to get a list of objects within a running JS engine with a JavaScript command?
On Mon, Sep 17, 2012 at 1:55 PM, Christoph T. tor...@gmail.com wrote:
I'd like to code an aspect oriented language extension for JavaScript. My
aspects should be defined in JavaScript. To weave in my advices I need a
list of all objects which are currently available within the current
context, to match their names e.g. against a regular expression to find out
if the new advice should be woven in. Is there a function within JavaScript
I can call to simply get this list?
This can only be done on a per-object basis, but you can get access to the
top-level list of objects via the global object with code similar to the
following (run in the global scope):
var k, v;
for( k in this ) {
if(!this.hasOwnProperty(k)) continue;
v = this[k];
... do your bit here ...
}
AFAIK there is no standard way to get the names of vars from a scope, e.g.:
function foo(){
var x, y, z;
... there is no standard way to derive the names x/y/z here ...
... either you know them or you don't ...
}
and i'm not sure that there's even a non-standard way to do it.
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Re: [v8-users] Very high call overhead to a specific C++ object member function
On Tue, Sep 11, 2012 at 5:24 PM, Stuart Allen stu...@lttlrck.com wrote: My C++ time stamp resolution was misleading. All is well after all. I should have known it was me and sending the mail late was a bad omen. Sorry for wasting your time. FWIW this _was_ actually a problem in some early v8 version (several years ago), and subsequent optimizations closed the gap between member and non-member calls. i don't have the ticket number handy (and it doesn't really matter any more), but there was actually a time where the difference between member and non-member calls was tremendous. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Re: ia32 bug?
On Fri, Sep 7, 2012 at 5:25 PM, Jakob Kummerow jkumme...@chromium.orgwrote: The part of the V8 API documentation that applies here is how to wrap an External (that was created in C++!) safely before passing it into JS (where it can't be used anyway! It can only be read from C++). And that's by storing it as in internal field of a valid JS object, not as a property that's accessible on the JavaScript side. Because the latter would be inherently unsafe. ... * Keep External's implementation basically as it is. i.e. either a Smi or a Foreign. If we do this, we should not keep External as a subclass of Value (perhaps a subclass of Data?) and we should remove the IsExternal predicate. This means that e.g. SilkJS has to change, following https://developers.**google.com/v8/embed#dynamichttps://developers.google.com/v8/embed#dynamic. As it is, one can easily crash SilkJS by pure JavaScript. I'm in favor of this. I guess we could provide a convenience function that wraps an External as an internal field into an otherwise empty object and returns that, but it would have to be called explicitly. FWIW, making an External not-a Value would break break ALL class bindings i've ever done (that's no small number of them), as well as every class binding in every framework i'm currently aware of (which of course is not all of them). That's a degree of incompatibility where i would have to pack up and move elsewhere (that's the reason i left Qt and the Autotools - too many incompatible changes breaking too many of my apps, causing me to spend too much time fixing things other people broke). In the beginning i used External directly as properties (because there was no documentation warning me otherwise), but quickly found that passing them around in JS segfaults (and i belong to the school of thought that script code is a sandbox and should never be able to segfault a native app). So i starting storing my (void*) via External in an InternalField (because that's how the API is apparently designed to be used). i've bound hundreds of classes using this approach, and i'd rather abandon my v8-using projects than go back and rework them all. :-[ -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Re: ia32 bug?
On Fri, Sep 7, 2012 at 5:57 PM, mschwartz myk...@gmail.com wrote: As I see it, the API you exposed in your header files and documentation is something of a contract, and I abided by it. My code has worked extremely well and quite robustly for well over a year. You change the API, you break my code and expect me to edit tens of thousands of lines of C++ code and the deal with the potential instabilities those changes will introduce. Amen, brother. As a compromise, may I suggest an alternative to External::New()? How about you implement an Opaque::New() that satisfies whatever you feel necessary under the hood? +1 -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Visual Studio 2012(ComboBox -SlectedItem)
On Thu, Sep 6, 2012 at 7:40 AM, vemuri revathi vemuri1...@gmail.com wrote:
i need your help, i am trying to create an example app which uses
combobox, i have entered the values/combobox items what i want is when i
click on a particular year it should be redirected to a particular page.
v8 has no idea what a checkbox is, and the following is not v8 code:
i have used the following code
if(yy.SelectedItem.ToString()==1960||1972||1984||1996||2008)
{
this.Frame.Navigate(typeof(Rabbit));
}
or 2nd type is the correct way
if(yy.SelectedItem.ToString()=={1960,1972,1984,1996,2008})
Nor is {#,#,#...} any sort of legal JS construct. (Perhaps you meant [#,
#, ...]?)
what i wnat is if we click on any of the above years it should navigate to
the following page givenThere are no errors ,can you
please tell me is this a correct format in declaring the values..
v8 doesn't know what a web page is, nor what a click event is. Those are
browser-side constructs.
i.e. this is not the proper group for your question.
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Re: [v8-users] 64-bit integers
On Fri, Jul 27, 2012 at 2:42 PM, Joran Greef jo...@ronomon.com wrote: Would it be possible to have proper support for native 64-bit integers and operations in Javascript? JS as a language does not specify them. It specifies a Number type and (IIRC) 51 (52? 53?) bits of integer precision. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] De-optimization of hot function when constructor adds methods directly to object
On Thu, Jul 19, 2012 at 3:04 AM, jMerliN jmer...@jmerlin.net wrote: So I can't get my head around why this happens (I haven't dug through v8's code to try to figure it out either), but this is really inconsistent to me with how v8 constructs hidden classes in general. The following is running in Node.js v0.8.2 (V8 v3.11.10.12). FWIW: v8's internal optimizations are internal implementation details, and any client code which optimizes specifically for them will, long term, require more maintenance and possibly have more bugs/regressions. It is, in general, poor practice for client code to assume that it knows ANYTHING with certainty about a 3rd-party library beyond what is documented in the library's API docs... errr... well, okay, that might be the problem right there. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] How to access Object content in C++
Your code is correct but Object.toString() (which is what you do with the
Ascii part) returns the string you are seeing.
(brevity... phone...)
- stephan beal
http://wanderinghorse.net/home/stephan/
http://gplus.to/sgbeal
On Jul 13, 2012 6:42 AM, Charles Han charleszhouxiao...@gmail.com wrote:
Hi,
I have managed to get an array back from JavaScript within C++. However,
when I got to access the elements of the array, I got something like this:
[object Object]
[object Object]
[object Object]
...
Code:
Array* uncompressed_json_objects = Array::Cast(*uncompressed_result);
for(int i =0; iuncompressed_json_objects-Length(); i++ )
{
LocalObject obj = uncompressed_json_objects-Get(i);
String::AsciiValue ascii(obj-ToString());
printf(%s\n, *ascii);
}
What's the method to get values from a V8 array objects? ()
Thanks
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Re: [v8-users] Re: How to access Object content in C++
On Fri, Jul 13, 2012 at 1:09 PM, Charles Han charleszhouxiao...@gmail.comwrote: Thanks for you reply. I can see what you mean in JavaScript but I don't understand how the data structure in the V8 Array, especially with all the JSON objects in the array. Can you please explain a bit more? An Array object holds arbitrary Value values, and each Value refers to one of the following value types: - Object - Array - Number - Null - String - Undefined - Function - Regex What your code does is extracts a value from the array (the value just happens to be-a Object) and then calls toString() on it. The result of calling toString() on an Object is [Object object], which is why you see that output. There is no generic, 1-size-fits-all object-to-string conversion. If you want to output the contents of an Object, you must first fetch those contents from the object or use a generic object-to-string mechanism like JSON.stringify(). On a related note: PLEASE don't use printf() for this type of thing. The v8 example code uses it and is a sign that an absolutely C++ beginner wrote that code (or that whoever wrote it doesn't care much for code quality). In C++ one uses std::cout and std::cerr for this type of simple output, not printf(), and _especially_ when only outputting a string as-is with no formatting. The peformance difference between: printf(%s\n, foo) and: puts(foo) is absolutely staggering (the second one is MUCH more efficient), but the end result is identical. printf() has its place, but (printf(%s\n,...)) is ALWAYS a poor choice - puts(...) is faster, uses less stack space, and is not subject to formatting-related injection bugs. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Re: NamedPropertyHandlers on Function object
On Fri, Jul 13, 2012 at 4:36 PM, mschwartz myk...@gmail.com wrote:
The possibilities I see for its use are to protect the global object from
extraneous modification and tracking changes to the global object.
Would that not be applicable for the recent thread about how to reset the
global object for re-use?
Another issue that comes up on this list from time to time is the ability
to reset the global object between requests in a server-side HTTP
scenario. If you can track changes made during one request, you can undo
them between requests.
That's what i get for not reading ahead before asking questions :/. Undo
might not always be feasible because changes could have side-effects which
the global object does not directly see. For example:
var foo = {}; // in global scope. Global knows about foo, but...
// in client code:
foo.bar = ...;
the global observer probably could not catch that and therefore not
generically revert it.
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Re: [v8-users] Re: How to access Object content in C++
On Sat, Jul 14, 2012 at 1:21 AM, Charles Han charleszhouxiao...@gmail.comwrote: BTW, are the JSON.parse and JSON.stringify built into the V8 lib? so I don't have to have the javascript file. Yes, an RFC-compliant JSON object is built in. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Destructors, a proposal of sorts
Sorry for top posting (tablet gmail makes it difficult to do otherwise)... I should have specied that correct, well-defined behaviour is far, far more important to me than gc-related lags. For me it has never been a question of performance, but of well-defined (non- performance- related) behaviours and returning resources to their owners. Yes, i use finalizers for all of my bound native types, but that is so that they have well-defined behaviour and has 0 to do with speed. Obviously that requirement is out of scope for chromium, which is fine in and of itself but very negatively impacts v8's re-use in other projects because we embedders often have to expend undue amounts of energy shoe-horning finalization into not only our c++ code but also into our docs and users. (Yes, it's our own fault, but without bindings to interesting natives js is not much use.) On Jul 12, 2012 8:43 AM, Sven Panne svenpa...@chromium.org wrote: The beating continues... ;-) Regarding Boehm's finalization is rarely needed: I think statement generally holds, *except* for the case we are discussing, namely writing a binding for a library with explicit allocation/deallocation where the deallocation part is not exposed in the binding. While it is very convenient for the user of such a binding, it simply wipes some complexity of the original library under the carpet, hoping for a magic solution from the binding language/runtime. When one uses finalizers for this magic solution, one faces another problem, namely the usual tradeoff between latency and throughput: For the vast majority of use cases of a GC, throughput is much, much more important than latency. In theory one could write a basically zero-latency GC (e.g. by doing reference counting on strongly connected components) where finalizers would fire immediately, but the overhead is so huge that no real collector I know of does it this way. So using finalizers in the real world will always involve some kind of delay, and you simply have to live with that. If the delay is intolerable and you have certain points in your application/library/framework where you know something about the lifetime of the underlying library objects (which seems to be the case for our example), you can deallocate the dead ones by hand, using the finalizer calls from the GC only as an additional hint to do this early. Having written several library bindings for myself, I am quite aware of the fact that the additional complexity of doing this in the binding layer is not nice, because it involves some housekeeping of the library objects there, but this is the price of hiding complexity from the user of the binding. Regarding Boehm's Section 3.3, bullet point #1:: This assertion is true, because in a library binding there are at least *2* objects involved, in our example the JavaScript canvas object plus the underlying Cairo surface. Cheers, S. -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Destructors, a proposal of sorts
On Tue, Jul 10, 2012 at 4:26 PM, mschwartz myk...@gmail.com wrote: meant to free the programmer from making certain mistakes. The answer that we should manually call a destroy() type function because we know it's a good time to do so suggests we should call delete (operator) as well for every object we call new (operator). FWIW: for ALL of my bound natives i bind a member destroy function (and typically use the try/finally approach to ensuring that they are cleaned up). The exact name of the function is class-dependent but the implementation is a template which does: a) unbinds the native pointer from the JS Object. b) calls the registered weak destruction callback (which almost always calls (delete theNative)). Afterwards, calling theBoundJSObject.anyMemberFuncWhichNeedsTheNative() will cause a JS exception to be thrown (cannot find native 'this' pointer), as opposed to crashing or stepping on a now-reallocated address which might now even belong to a different class of object. http://code.google.com/p/v8-juice/source/browse/convert/include/cvv8/ClassCreator.hpp#1017 -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Destructors, a proposal of sorts
On Wed, Jul 11, 2012 at 4:38 PM, Andreas Rossberg rossb...@google.comwrote: In any case, before you conclude that finalization is the answer to your problems, let me +1 Sven's recommendation on reading Boehm's paper on the subject. Finalization is pretty much an anti-pattern. There are some rare, low-level use cases, but usually it creates more problems than it solves. That's why we only provide it in the C++ API. Just to beat a long-dead horse for a moment... Quoting Boem's paper: Page 1: We argue that although finalization is rarely needed, it is often critical when it is needed. In these cases, its absence would render the garbage collector useless. Rarely needed is, in my (not inconsiderable) experience, 100% wrong for JS bindings. The vast majority of the interesting client-side NATIVE types which we want to bind to JS require resource acquisition and a large percentage of them require well-defined finalization/destruction in order to guaranty proper behaviour. Examples, just off the top of my head: - File handles must be close()d in order to ensure that they are flushed. Yes, the OS closes them when the process exit()s, but AFAIK they are not automatically flush()ed. - Database drivers, statement handles, and query cursors all have very specific cleanup requirements, and failing to properly close() a db handle could (though admittedly shouldn't) lead to undefined behaviour e.g. db corruption. - Anything which heavily relies on parent/child relationships, UI toolkits being a prime example. Getting those working properly in JS can be a real PITA because the child/parent relationships must be tracked in both JS and native space in order to keep all the objects around for their proper lifetimes. (When i first implements an ncurses binding for JS i quickly found i had to make JS aware of all child window references to keep them from being GC'd out from under the parent window's nose.) We (client-side users of scripting engines) don't bind trivial classes to native implementations. Such impls are done in JS because it's 100x times easier to do so (e.g. the canonical Point class example). When we bind natives its because we need native functionality which we cannot get at from JS, and the vast majority of such functionality requires access to interesting native resources with arbitrarily complex compositions and cleanup requirements. i don't know of a single commonly-used C/C++ library which does _not_ require that clients clean up resources it asked the library to allocate for them. Section 3.3, bullet point #1: There is usually not much of a point in writing a finalizer that touched only the object being finalized, since such object updates wouldn't normally be observable. i understand that this assertion can be true, but it assumes that the statement from Page 1 is true, which it is absolutely not for the generic case when binding native C/C++ types to JS. To be clear: i'm not picking no v8 here. In time since i wrote the original gripes which Michael S. linked to in the top post of this thread, i have since come to understand much more about the difficulties of finalization ordering and whatnot, and have a much deeper appreciation for the nature of the problem. Nonetheless, assertions like Boem's quotes above, in my opinion, simply hand-wave away a _majority_ of use cases as not useful or rarely seen, when in fact the problem is that they are just damned difficult to solve. Obviously Boem is the top of his field, and i don't discount his brilliance in this subject matter, but hand-waving away such problems as being infrequent does him no credit. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Destructors, a proposal of sorts
On Wed, Jul 11, 2012 at 7:02 PM, Stephan Beal sgb...@googlemail.com wrote: Section 3.3, bullet point #1: There is usually not much of a point in writing a finalizer that touched only the object being finalized, since PS: the typos are mine, not Boem's - my PDF reader won't let me copy/paste :/. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Native objects with uncallable constructors
On Wed, Jul 11, 2012 at 4:57 AM, Mike Schwartz myk...@gmail.com wrote: Exposed constructor always throws an error. document.createElement calls an unexposed factory method, which calls a protected constructor. There is a case when a ctor needs to be exposed but should not be invoked by clients: to allow the use of the instanceof operator. As a concrete example, in my JSPDO (PHP PDO clone) i initially hid the Statement class' constructor from the clients. While writing client-side code i discovered a need to determine if an object is-a Statement[1] or not (as opposed to a Object or Array), and ended up having to expose the ctor. However, i took the draconian steps of explicitly documenting the ctor as not to be used for anything other than instanceof checks, explicitly did not document the arguments it takes, and internally intentionally make it (slightly) difficult for clients to call the ctor (i.e. they'll only know what to do if they read the C++ code, and if i catch them doing that i'll change it just to break their script code ;). Happy Hacking! [1] = http://code.google.com/p/v8-juice/wiki/JSPDO_API#JSPDO.Statement -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Native objects with uncallable constructors
Briefly (i am on a tablet) : this can be done a few different ways, but getting at the code is really tedious on a tablet :-\. I will post some links to examples for you tomorrow. One quick idea: have the bound ctor allow only some weird arguments and throw for everything else (and don't document them in the js interface) . Your c++ code can then pass the weird args to FunctionTemplate::NewInstace(). Example: require the args (null, undefined, the real args...). Then throw if the args do not comply. There are other (cleaner) ways, too, e.g. passing a v8::External to the ctor (js code cannot create these). On Jul 10, 2012 10:34 PM, Kevin James kevinwja...@gmail.com wrote: I want to write bindings for C++ objects whose constructors can't be called directly. Examples of what I'm talking about in a browser would be Element, ImageData, and Canvas. These are defined as functions in the global namespace, but if a script tries to call new Element(), an exception is thrown. Instead an appropriate function has to be called, for example document.createElement(). How are the bindings for these objects are written? If I create a FunctionTemplate, I can have it's constructor always throw an Illegal Constructor exception, but then how will my C++ code instantiate one of these objects? Thanks. -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Native objects with uncallable constructors
I found an example of the magic args approach combined with v8::External to differentiate how certain objects are constructed: http://code.google.com/p/v8-juice/source/browse/trunk/src/lib/juice/PathFinder-cw.cc#72 Feel free to contact me off-list with questions about that code. On Jul 10, 2012 11:09 PM, Stephan Beal sgb...@googlemail.com wrote: Briefly (i am on a tablet) : this can be done a few different ways, but getting at the code is really tedious on a tablet :-\. I will post some links to examples for you tomorrow. One quick idea: have the bound ctor allow only some weird arguments and throw for everything else (and don't document them in the js interface) . Your c++ code can then pass the weird args to FunctionTemplate::NewInstace(). Example: require the args (null, undefined, the real args...). Then throw if the args do not comply. There are other (cleaner) ways, too, e.g. passing a v8::External to the ctor (js code cannot create these). On Jul 10, 2012 10:34 PM, Kevin James kevinwja...@gmail.com wrote: I want to write bindings for C++ objects whose constructors can't be called directly. Examples of what I'm talking about in a browser would be Element, ImageData, and Canvas. These are defined as functions in the global namespace, but if a script tries to call new Element(), an exception is thrown. Instead an appropriate function has to be called, for example document.createElement(). How are the bindings for these objects are written? If I create a FunctionTemplate, I can have it's constructor always throw an Illegal Constructor exception, but then how will my C++ code instantiate one of these objects? Thanks. -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Re: V8 and pthreads
On Thu, Jul 5, 2012 at 4:21 PM, mschwartz myk...@gmail.com wrote:
// TryCatch tryCatch;
printf(CALL\n);
v = func-Call(context-Global(), 1, av);
// if (v.IsEmpty()) {
// printf(Exception!);
// ReportException(tryCatch);
// }
Out of curiosity: did you comment that TryCatch out because it is no longer
relevant for you or because it doesn't work? i remember having unspecified
headaches with local-scoped TryCatches, very possibly due to my
inadvertent misuse of them. If the above is how they are supposed to be
used, i'll take another look at the code i had such problems with.
Also of note is if I throw an Error() from JS in a thread, it's caught, but
the TryCatch doesn't seem to have valid data.
Ah, that's what i get for not reading to the end before asking questions :/.
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Re: [v8-users] Error when linking libv8_base.a into a shared object on x64 linux
On Mon, Jul 2, 2012 at 1:13 PM, Michael Schwartz myk...@gmail.com wrote: The more interesting question is why he thinks he needs -fPIC for a static library. The error message indicates the elf file contains a 32-bit relocation and it needs to be a 64-bit one. FWIW: i had the same problem with libsqlite4.a (yes, 4) until i added -fPIC to its build options. Position Independent Code (PIC) is typically (almost always) used in shared libraries. Ubuntu likes it to always be set :/. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] V8 and pthreads
On Mon, Jul 2, 2012 at 1:46 PM, mschwartz myk...@gmail.com wrote: Anyhow, I hope the code is of interest to someone. Absolutely. i tried to do the same in SpiderMonkey several years ago and failed miserably. It actually worked on single-core systems (where no real MT was going on), but as soon as i moved to 2-core it all exploded very horribly. Thank you for the code and link :). -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Re: Spring-cleaning tools/test.py
On Mon, Jul 2, 2012 at 1:58 PM, Jakob Kummerow jkumme...@chromium.orgwrote: - distribution of testing work in the local network (think distcc). Details will be announced when the feature is ready; of course it will be opt-in. A very far-fetched idea here: imagine if Google or Chromium provided public distcc servers... -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] V8 and pthreads
On Mon, Jul 2, 2012 at 3:11 PM, Michael Schwartz myk...@gmail.com wrote:
However, a long running thread could call sleep(0) or pthread_yield()
periodically to allow the other threads to run.
From what i understand, every time the JS-side code calls back into v8
(e.g. via a function call), v8 gets a chance to interrupt it. This doesn't
protect against infinite loops which don't call back into v8, of course.
while(true){++i} would probably never yield.
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Re: [v8-users] V8 and pthreads
On Mon, Jul 2, 2012 at 6:00 PM, Michael Schwartz myk...@gmail.com wrote: I'm not clear on when a thread running in v8 might be preempted. Likely on entering or exiting functions (when doing stack checks, I think I remember reading about). FWIW, that's also my recollection. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] instanceof Array fails after ReattachGlobal
On Tue, Jun 26, 2012 at 5:34 PM, MikeM mi...@reteksolutions.com wrote: I suppose I could keep using the same Context over and over, but I would need a way to wipe out any local var declarations between executions and only keep the built-ins. On a similar note, you probably couldn't protect against: Array.foo = whatever; i suspect that the only safe way to do it is recreate the whole sandbox on each run. Not doing so will eventually lead to weird behaviours, i think (via sneaky modifications like custom properties on built-ins). -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] instanceof Array fails after ReattachGlobal
On Tue, Jun 26, 2012 at 6:27 PM, MikeM mi...@reteksolutions.com wrote: V8 is still a bit foreign to me. I'm trying to break that barrier. Welcome aboard - i hope we can help you get over the initial humps. It can be a bumpy ride. How do I create a global template with a complete set of built-ins? I'd love some sample code that does this... :-) From my understanding you've already done that, but you're trying to take it a step further and transport the object from its initial context to another one. Can that work? i don't know for certain, but i _suspect_ the answer is something along the line of it can, with some notable caveats like object/namespace pollution. The vast majority of apps have (in my rather long but narrow experience) a single context which starts life early on in main() and ends life shortly before or after main() returns (depending on whether one manually destroys it or lets the dtor do its work). That is of course not a rule, but is the common pattern for the apps i've worked on (http://code.google.com/p/v8-juice). -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] instanceof Array fails after ReattachGlobal
On Tue, Jun 26, 2012 at 6:53 PM, Stephan Beal sgb...@googlemail.com wrote: Welcome aboard - i hope we can help you get over the initial humps. It can be a bumpy ride. Tip #0, in case you haven't come across this already: always develop against a debug build of libv8. Not doing so is basically futile because v8 _will_ crash when you mis-use it (and you _will_ mis-use it at times) and the debug builds dump a surprising amount of detail about the crash to stderr when they crash. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] instanceof Array fails after ReattachGlobal
On Tue, Jun 26, 2012 at 7:21 PM, MikeM mi...@reteksolutions.com wrote: I'm open to any method of making this happen. Thanks for the help! i unfortunately cannot say much on the topic of multiple contexts and de/serialization of v8 state across requests, but i suspect that Michael Schwartz (who also responded earlier) can tell us something informative on the topic. He's the architect behind http://silkjs.org/, which has a larger scope than the library-level code i tend to write. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] instanceof Array fails after ReattachGlobal
On Tue, Jun 26, 2012 at 7:47 PM, Michael Schwartz myk...@gmail.com wrote: Something else I discovered early on in SilkJS development is that you can call from JS, a C++ function that calls fork() and returns. After the return, you have a parent and child process resuming in JS context. The child process is a literal clone of the parent, including the context and it's global and everything compiled in. So if you have a pristine global object set up by JS and call fork() for each request, you have a pristine global in the child Nice idea. To drag us off topic for a moment... i implemented fork() for SpiderMonkey some years ago but never really trusted that the JS engine would behave properly if forked, so i never used it. Does v8 provide any specific guarantees in the face of forking, or are you aware of any notable down-sides to using fork() from JS in generic client code? -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] instanceof Array fails after ReattachGlobal
On Tue, Jun 26, 2012 at 8:13 PM, Michael Schwartz myk...@gmail.com wrote: o The child process has its own copy of the parent's descriptors. These descriptors reference the same underlying objects, so that, for instance, file pointers in file objects are shared between the child and the parent, so that an lseek(2) on a descriptor in the child process can affect a subsequent read or write by the parent. This descriptor copying is also used by the shell to establish standard input and output for newly cre- ated processes as well as to set up pipes. That's the kind of thing i was looking for. e.g. sharing a stdout handle could be mildly problematic. Sharing an sqlite3 db file handle or a MySQL socket (it connects to a localhost socket file by default) could be even more-so. Notably missing is that fork() does not clone any threads associated with the parent process. I've been told by V8 committers that there are no threads running of consequence to the child processes. I was initially concerned that maybe some thread in v8 was doing the hot spot type optimization of the generated machine code, but I'm told that this isn't done by a thread. Maybe fork() loses some profiling information. Certainly fork loses the debugger; to get around this, the -d flag to the httpd server tells it to not fork() but to call the HttpChild's run function. You can fully debug with node-inspector that way (works great!). That's all great information, thanks. (Mis)Interactions with internal JS VM state were always highest on my list of suspicious behaviour. i never personally saw problems with it, but i bailed out early on because of my complete uncertainty with what was happening in the VM. Looking back on the code[1] now, it was trivial to implement. i'll give this a whack in v8. http://spiderape.svn.sourceforge.net/viewvc/spiderape/plugins/SystemFuncs/system_funcs.cpp?revision=65view=markup line 483 -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] instanceof Array fails after ReattachGlobal
Tue, Jun 26, 2012 at 8:26 PM, Michael Schwartz myk...@gmail.com wrote: You can also encounter this error with applications that fork child processes, all of which try to use the same connection to the MySQL server. This can be avoided by using a separate connection for each child process. Plus, I'd think that socket would become a significant bottleneck, since you'd be talking basically to a single thread in the MySQL server... That's the crux of my problem: i write almost exclusively library-level code and i can't enforce this type of policy on downstream clients in any useful way. So my only defense against such things is either not providing such a feature (let the client do it) or documenting them with big fat hairy warning labels :/. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] 'Create instance of instance' or 'returning a v8::Function from NewInstance()'
On Fri, Jun 15, 2012 at 10:20 AM, thewilli thewi...@googlemail.com wrote: *var Float = new Type(Float); var myFloat = new Float(34.2);* and want to avoid factory methods like *var myFloat = Float.createInstance(34.2)*; You can'd _call_ individual instances (not portably), but you can of course do: var Float = Somefactory.FloatFactory; var myFloat = new Float(...); which is not very far removed from what you demonstrate. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] [SIGSEGV] v8::HandleScope::HandleScope()
On Fri, Jun 15, 2012 at 12:38 PM, Vyacheslav Egorov vego...@chromium.orgwrote: Also ensure that the thread that invokes your even_handler owns V8 Isolate if you have multiple threads using V8 concurrently. Additionally, the timing of the call is important. If you do it at the very start of main(), before setting up v8, it won't work (crash). The Most Important Tip for v8 is what Vyacheslav said: link to the debug library because when that one crashes it dumps a lot of useful info to the console. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Does V8 has methods to parse json in c++.
On Sun, Jun 10, 2012 at 12:56 AM, Chris Jimison cjimi...@gmail.com wrote:
HandleObject result;
if (sourceFlatten-IsSeqAsciiString()) {
result = JsonParsertrue::Parse(sourceFlatten);
} else {
result = JsonParserfalse::Parse(sourceFlatten);
}
return result;
}
i don't think that code accepts Array input.
Why not just get the JSON property from the global scope, Cast() it to an
Object, get it's parse property, cast it to a Function, and Call() that?
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Re: [v8-users] XOR two 31-bit unsigned integers much faster than XOR two 32-bit unsigned integers?
On Wed, May 30, 2012 at 6:25 PM, Vyacheslav Egorov vego...@chromium.orgwrote: c) stop doing 0 at the end; A side question: what does 0 do? i have never seen the operator before this thread and never seen a 0-bit shift anywhere. :-? -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] JavaScript Proxy object
On Wed, May 23, 2012 at 7:05 PM, Michael Schwartz myk...@gmail.com wrote:
Does it remove what it consumes from argc and argv?
i just came across this years-old snippet...
if(0)
{ /** f*** - SetFlagsFromCommandLine() changes argv such that the
-- arg and those following it are stripped!
*/
typedef std::vectorchar * AV;
AV vargv(static_castsize_t(argc), 0);
int i;
for( i = 0; i argc; ++i )
{
vargv[(unsigned int)i] = argv[i];
}
v8::V8::SetFlagsFromCommandLine(i, vargv[0], true);
}
else
{
// or we could use the undocumented 3rd arg:
//v8::V8::SetFlagsFromCommandLine(argc, argv, false);
}
The first comment is where i remember having problems: anything after a
-- argument is stripped completely. That was a problem for me because i
use -- to signal the start of args to pass to the client-supplied JS script
(as opposed to shell-level args).
--
- stephan beal
http://wanderinghorse.net/home/stephan/
http://gplus.to/sgbeal
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Re: [v8-users] Re: calling setRequestHeader
On Fri, May 4, 2012 at 2:51 PM, souad agoun souad.ag...@gmail.com wrote: why v8 does not support xmlhttprequest object ? Because core JS does not define that functionality. That is a w3c standard based upon JS. The Rhino Book from O'Reilly is the only JS book i've seen which discusses this distinction in detail and clearly separates the core language APIs and (e.g.) the DOM APIs. JS defines NO I/O functionality (whether network or file or terminal), and ANY I/O performed by JS is being performed a non-core-language function. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] No whitespaces in string, what have I done wrong?
Google for std::iosteam skipws.
- stephan beal
http://wanderinghorse.net/home/stephan/
http://gplus.to/sgbeal
On May 2, 2012 2:47 AM, idleman evoo...@gmail.com wrote:
Why does all white spaces get removed in the example below?
//C++
HandleValue System::log(const Arguments args)
{
for(int i = 0, s = args.Length(); i s; ++i) {
String::AsciiValue ascii(args[i]);
os.write(*ascii, ascii.length()) std::endl; //os =
std::ostream object
}
return Undefined();
}
//Then in javascript, there the System object have been exposed to
JavaScript.
System.log(How are you?); //prints howareyou? not how are you?, e.g
no whitespaces
In the example do I get the text: Howareyou?, not How are you?, what
does I wrong? Why are all white spaces removed? The std::ostream::write
write oformatted output, so it does not remove any white space, so it is
not the problem.
Thanks in advance!
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Re: [v8-users] How do I set what this refers to?
On Wed, May 2, 2012 at 6:07 PM, Andreas Rossberg rossb...@google.comwrote:
(function() { script-text }).call(implicitThisObj)
See also Function.apply(). The only difference between apply() and call()
is how the 2nd+ argument(s) are passed to it:
myFunc.call( myObj, 1, 2 );
===
myFunc.apply( myObj, [1, 2] );
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Re: [v8-users] Re: trunk fails to build
On Fri, Apr 27, 2012 at 7:27 PM, Michael Schwartz myk...@gmail.com wrote: This is on a freshly installed Ubuntu in a VM. There is no system wide v8.h header. The -I./v8-read-only/include switch is having it read the v8 from the include directory. FWIW: [stephan@host:~/src/google/trunk]$ svn info Path: . URL: http://v8.googlecode.com/svn/trunk Repository Root: http://v8.googlecode.com/svn Repository UUID: ce2b1a6d-e550-0410-aec6-3dcde31c8c00 Revision: 11461 Node Kind: directory Schedule: normal Last Changed Author: yang...@chromium.org Last Changed Rev: 11442 Last Changed Date: 2012-04-26 10:21:05 +0200 (Thu, 26 Apr 2012) [stephan@host:~/src/google/trunk]$ make x64.debug library=shared cmp: EOF on out/environment GYP_GENERATORS=make \ build/gyp/gyp --generator-output=out build/all.gyp \ -Ibuild/standalone.gypi --depth=. -Dtarget_arch=x64 \ -S-x64 -Dcomponent=shared_library -Dv8_can_use_vfp_instructions=true ...snip... TOUCH /home/stephan/src/google/trunk/out/x64.debug/obj.target/build/All.stamp make[1]: Leaving directory `/home/stephan/src/google/trunk/out' == works for me Ubuntu 12.04 w/ gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Convert LocalValue array to Arguments, or am I passing around wrapped Objects incorrectly?
On Thu, Apr 26, 2012 at 6:10 PM, Ryan Cole r...@rycole.com wrote: think I've almost got it, but I am trying to figure out how to convert a LocalValue array back into an Arguments instance, so that I can pass it to a function of mine. AFAIR, client code cannot create Arguments objects. They are created indirectly when we (the clients) call Function::Call(). -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Convert LocalValue array to Arguments, or am I passing around wrapped Objects incorrectly?
On Thu, Apr 26, 2012 at 10:21 PM, Ryan Cole r...@rycole.com wrote: Ok. I guess that's where I need to figure out how to adjust my code, then. I went ahead and wrote a longer description of my situation on stackoverflow.com, because I felt like I could format it better and get the whole description out there all at once without having to re-write it for other places. Here's a link to that: http://stackoverflow.com/questions/10340552/how-to-pass-a-wrapped-c-object-to-a-javascript-callback There is no 3-line answer, but you might find some of these docs interesting (if only for ideas): http://code.google.com/p/v8-juice/wiki/V8Convert http://code.google.com/p/v8-juice/wiki/V8Convert_FunctionBinding http://code.google.com/p/v8-juice/wiki/V8Convert_XTo http://code.google.com/p/v8-juice/wiki/V8Convert_ClassCreator In particular, the 2nd link (2nd to last section of the page) might be relevant for you. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
Re: [v8-users] Leaking data in SetAccessor
On Sat, Apr 14, 2012 at 3:59 AM, Gerhans gerh...@gmail.com wrote: Thanks for the reply Stephan. You're imagining a mapstring,void* kind of thing? Ah, i didn't consider that each _instance_ of course has its own value. i was thinking about saving the last one in a static. Seems workable, and I may have to resort to that, but I was hoping to understand the nature of the problem better. Is this my bug or V8's? I'm new to V8 so it seems likely I'm doing something wrong. i don't see anything wrong with what you've done :(. -- - stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users
