Closures not thread-safe?

[Frantzius, Jörg]

… to correct myself, with code that contains closures, it’s probably global-per-thread on a single engine that remains as the least resource-consuming option (we were using a single global on single engine for all threads, in order to share expensively computed Javascript state between them).

From what I understand, global-per-thread could be implemented e.g. by having a ThreadLocal<ScriptContext> and always using that as the context in ScriptEngine.eval(script, context).

It would be good to know then whether global-per-thread on single engine still allows for sharing Nashorn’s code optimization between threads? That would already be great (and as Nashorn *is* great, I’m positive here :)

Regards,
Jörg


Am 19.02.2017 um 00:47 schrieb Frantzius, Jörg <Joerg.Frantzius at aperto.com<mailto:Joerg.Frantzius at aperto.com>>:

Hi,

it begins to dawn on me that closures aren’t thread-safe, at least that would explain crosstalk issues we’re seeing in JMeter tests (with a single engine for multiple threads).

It would be good to know (and I guess for others as well) if somebody can confirm this?

Perhaps thread-safety of closures was thinkable if Nashorn somehow stored closure state in ThreadLocals, but I guess that’s neither happening nor planned?

From what I understand, closures are pervasive in Javascript code out there, and anybody using such code will currently be forced to use engine-per-thread.

Thanks for any hints,
Jörg


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Dipl. Inf. Jörg von Frantzius, Technical Director

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---

Dipl. Inf. Jörg von Frantzius, Technical Director

E-Mail joerg.frantzius at aperto.com

Phone +49 30 283921-318
Fax +49 30 283921-29

Aperto GmbH – An IBM Company
Chausseestraße 5, D-10115 Berlin
http://www.aperto.com<http://www.aperto.de/>
http://www.facebook.com/aperto
https://www.xing.com/companies/apertoag

HRB 77049 B, AG Berlin Charlottenburg
Geschäftsführer: Dirk Buddensiek, Kai Großmann, Stephan Haagen, Daniel Simon