On Fri, Feb 27, 2015 at 2:43 AM, Michael Hablich <habl...@chromium.org> wrote:
> Hey v8-users, > > we're making big changes to the api (again). We've found that our api makes > it extremely difficult to write exception safe code. > > *Reference issue* > https://code.google.com/p/v8/issues/detail?id=3929 > > *Further description* > Consider the following: > > Local<Value> x = some_value; > s = x.ToString(); > // in the current context, ToString might throw an exception, run out > of stack space, whatever... > // if that happens we just return an empty Local<String> > s->Anything() // Crash! > > There's too much implicit stuff happening here, and it's bad. It's especially > bad if you use threads and rely on TerminateExecution(), which causes > lots of v8 function to return empty handles unexpectedly. > > To fix this, we will begin adding functions whose signature makes it > impossible > to make this mistake and we will deprecate and eventually remove all old > functions. The new functions will in general come in > two flavours: > > functions like: > Local<String> ToString(Isolate*); > > will become: > MaybeLocal<String> ToString(Local<Context>); > > and functions like: > double NumberValue(); > > will become: > Maybe<bool> NumberValue(Local<Context>); > > The Maybe values ensure at compilation time that the value returned is checked > by the embedder, and the explicit Context makes it clear that a context > is actually required and that javascript may be executed in that context. > I'm curious about this bit of the design: why was it decided to add an argument here rather than require a Context to be entered (via Context::Scope)? Rather late to the discussion, I know. Apologies - Adam > *Timeline* > We will add the new API parts gradually to the codebase. When this is > finished there will be approx. 6 weeks of time where the old and the new > API will exist side-by-side. This is a good time to make the adjustments in > your embedding code. After this period the old API will get removed. > > We apologize in advance for any trouble this may cause, but we're positive > that this change will reduce crash rates for practically all v8 embedders. > > Cheers, > Michael Hablich > > -- > -- > 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/d/optout. > -- -- 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/d/optout.
