Feature request: mysqli_poll async support for prepared statements also

[macropay-solutions]

Description

Recently PHP True Async RFC was rejected. It was supposed to have ONE worker and multiple coroutines. But that functionality would be useful only for external calls (like DB, HTTP etc.) that need time to respond.

While for HTTP calls there is curl_multi_init, for parallel DB queries there is no alternative when prepared statements are needed.

So we propose to finish mysqli_poll or implement similar one for running parallel prepared statements.

We already use mysqli_poll to eager load relations in Eloquent that don't have bindings when the number of relations is big (over 20).

https://stackoverflow.com/questions/36358865/mysqli-async-available-with-prepared-statements-in-php

[iluuu1994]

Note that while the async RFC vote failed, the feature request isn't abandoned. Regarding adding a non-blocking mode to mysqli and other db extensions, maybe @kamil-tekiela can comment on how realistic that is, and how to push it forward.

[kamil-tekiela]

I haven't investigated how much effort it would be to create some kind of asynchronous DB extension or add-on to an existing one, or even if it would be possible to finish the mysqli async feature, but I imagine it would be possible even without PHP's true async.

Mysqli's async feature is a pretty naive and simple asynchronous solution. All it does is send the query and not poll for a reply immediately. The mysqli_poll() function is just a select on the I/O.

What I would rather see more is a proper solution with Promises and for PDO. It could be a PDO extension too. I'm sure it could be implemented in a similar manner and for all types of DBs. Someone just needs to want to do it and propose a solution to the PHP community.

[macropay-solutions]

@kamil-tekiela
Thank you for your input. This feature would help PHP more than async with ONE worker and multiple coroutines.