On 25/01/2020 18:51, Robert Hickman wrote:
Yes that is what I was thinking, for example there is a userspace implementation 'Swoole' that works in the following way, ReactPHP is similar although I won't include that example as well.
So trying to get concrete: the first "official" component we'd need would be an outer event loop, mapping requests and responses to the parameter and return values of userland callbacks. In principle, not too difficult, although I'm sure there are plenty of devils in the details.
In my mind right now, everything should be shareable within a single process, as one could do in the Swoole example above, nothing stopping you defining a global in that script that could cache data in-process. NodeJS, Python (wsgi) and others work fine using this model and allow sharing of data within the same process. Trying to limit it to only some types of things would be more complex as each type of thing would end up having a different programmatic interface.
I may be wrong, but I think this is where it gets complicated. It's not that we'd want to deliberately have different things have different behaviour between requests, it's just that we've got a bunch of existing stuff built on the assumptions of the current architecture.
In a single-threaded event loop, you want as much as possible to be asynchronous, which is why both Swoole and React have a lot of modules for things like network requests, file I/O, databases, and general asynchronous programming.
Other things just wouldn't exist if PHP hadn't been modelled as shared nothing from the beginning. Would set_time_limit() still be global, and abort the server after a fixed number of seconds? Or would it configure the event loop somehow?
I think there'd need to be at least a roadmap for sorting out those questions in the official distribution before it felt like a properly supported part of the language.
Regards, -- Rowan Tommins (né Collins) [IMSoP] -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
