Share context/JS bindings

[Benjamin Sieffert]

Hi Axel,

I tried doing a similar thing for a while and found there is no pretty
way to do it from the Java-side.
I think the best solution is making your JS-code have no global state,
by utilizing function scopes* and maybe small (custom, mutable)
context objects that get passed around.
Generally, the public API for providing bindings etc. certainly looks
nice, but in practice I think some use-cases might just be too
complicated to be supported.

Regards,
Benjamin

* For your small example, simply wrapping it in a function would
already get rid of the issue and would even be completely thread-safe.
(function() {
    var found;
    print found;
    found = 1;
})();

On 14 June 2016 at 10:41, Axel Dörfler <axeld at pinc-software.de> wrote:
> Hi Hannes,
>
> Am 14/06/2016 um 09:53 schrieb Hannes Wallnöfer:
>>
>> The problem seems to be that bindings.clear() uses the ECMAScript
>> delete operation to clear the bindings, and that will only delete a
>> property if it is configurable. However, var declarations are
>> non-configurable and therefore „survive“.
>>
>> I’m not sure how to work around this, and possibly we should fix our
>> implementation of clear to include non-configurable (declared)
>> variables.
>
>
> That would be great!
>
> Is there any other way of reusing the JS context that does not exhibit the
> issue? Recreating for every call is very expensive (having a single engine,
> using compiled scripts, and sharing the context brought a 100x speedup in
> execution time -- and the context was responsible for half of it IIRC).
>
> Bye,
>    Axel.



-- 
Benjamin Sieffert
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