HHVM hacklang async and await keywords on the roadmap

[RdeWilde]

Now that HHVM is released with support for HACK-lang, it is possible to use new features like 'async' (http://docs.hhvm.com/manual/en/hack.async.php). What will be the impact on React?

Will React make use of these features? As I'm not very familiair with React yet, what would be important differences between React promises and Hack asyncs?

[cboden]

Currently async/await are syntactic sugar (which isn't a bad thing). I asked a FB engineer how this functionality was implemented about a month ago. Their implementation is more suspended processing (like generators/co-routines) on a single core that can work with an asynchronous socket - unlike other implementations that would offload the work to a thread and be concurrently processed.

The advantage of this technique is you can make network requests asynchronously (such as MySQL), carry on execution of your code, and then choose when to block the application. Much like mysqli::reap_async_query but through a nicer and more generic interface.

Hack's async/await lets you make a request asynchronously over a network and choose when to block execution whereas everything in React is meant to be asynchronous all the time. React is run in an event loop and a notification is received and propagated when the async request is done whereas Hack is procedural and the developer decides when to block execution to wait for the response.

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Given their documentation I wouldn't be surprised if Hack eventually changed the engine of async/await to offload all processing to be concurrent, but that doesn't seem to be the case today.

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Promises are an object that represent a future value. They will eventually be resolved and can have callbacks triggered when they become a value.

[JordanRL]

Interesting.

I'm currently building a very big application based on React. Basically a whole framework. I have 7 developers on my team right now that are all working to develop this application, and we plan on open sourcing it once we have an initial stable version.

Part of our architecture is that we split the Model/Domain into different servers, so we make socket connections to those servers in order to request and receive processed data from the Model.

I had been considering firing all those requests at once with async in Hacklang, and then having an await at the bottom of the controller right before it wraps everything up. It sounds like this sort of network communication is exactly what async is for in Hacklang, correct? Does it provide any sort of benefit over React's default handling of such a situation?

[cboden]

@no1youknowz Facebook seems to be putting a lot more into async now. I'll be revisiting it once they have streams supporting the async syntax.

[joshdifabio]

http://docs.hhvm.com/manual/en/function.hack.stream-await.php

[aftabnaveed]

is ReactPHP supported on HHVM ?

[clue]

is ReactPHP supported on HHVM ?

Yes, ReactPHP does support running on HHVM.

(Though this issue is more geared towards taking advantage of HHVM hacklang's async and await keywords)

[clue]

I'd like to make this actionable, so I'm wondering what needs to be done here? 👍

React runs on both Zend PHP and HHVM and it's unlikely this is going to change any time soon.

The async and await keywords are currently only supported on HHVM and we currently do not take advantage of them.

How could we possibly take advantage of them? What kind of benefits would this give us?

[clue]

I'm closing this for now as it hasn't received any input in a while and I believe this has been answered. Please come back with more details if this problem persists and we can reopen this 👍