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phpv8 / v8js

V8 Javascript Engine for PHP — This PHP extension embeds the Google V8 Javascript Engine
http://pecl.php.net/package/v8js
MIT License
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Persisting V8 instance between requests in php-fpm #78

Closed esv closed 10 years ago

esv commented 11 years ago

Hi!

Is it possible to persist V8 instance between requests in web server? I found old issue on this topic https://github.com/preillyme/v8js/issues/4 and seems it was impossible back than. Do you have plans to implement it? I think it would be useful feature, like persistent connections in mysql extensions.

cscott commented 11 years ago

What exactly do you want here? Do you want global variables set in JavaScript to persist between requests? If so, that's impossible, as PHP is just not set up that way. But if you just want to more efficiently reload scripts, there are ways to make that persistent. On Oct 31, 2013 9:25 AM, "esv" notifications@github.com wrote:

Hi!

Is it possible to persist V8 instance between requests in web server? I found old issue on this topic #4https://github.com/preillyme/v8js/issues/4and seems it was impossible back than. Do you have plans to implement it? I think it would be useful feature, like persistent connections in mysql extensions.

— Reply to this email directly or view it on GitHubhttps://github.com/preillyme/v8js/issues/78 .

esv commented 11 years ago

Exactly: creating V8 instance (code "new V8Js();") on my machine takes 20ms, I want it to take <1ms.

But if you just want to more efficiently reload scripts, there are ways to make that persistent.

This can be done via V8Js::registerExtension?

saveriocastellano commented 10 years ago

what we want is that the v8 context is persistent accross different php requests, this doesn't refer to specific global variables in javascript but to the whole javascript context. Currently the js context is bound to the PHP instance of the the running script, when the script completes the js context is released.

For this v8js extension to be fully usable in real scenarios it is necessary to have a way of making the context persistent so that it can be re-used accross multiple requests

cscott commented 10 years ago

You would need to be running Apache in "Pre-fork" or "Worker MPM" mode (or IIS in ISAPI mode) and be using the multiprocess or multithreaded SAPI for PHP. You wouldn't be guaranteed that the context would be reused, but a small number of contexts would typically be used for a largish number of requests. Again, you couldn't share global variables, because contexts aren't guaranteed to be reused. V8 supports this; we just need to hook up some bits in v8js differently.

stesie commented 10 years ago

PHP has a "shared nothing" architecture ... and I don't think V8Js should "solve" this by decoupling PHP lifetime from V8 lifetime, contextwise. This would require to invalidate PHP objects exported to Javascript as soon as the PHP request ends (since they're forcibly destroyed by PHP engine then; and we can't and shouldn't change that), ... and that'd get really messy then.

Closing this now since there's been no discussion for a long time now.