[WIP] Refactor to use new futures api

[afinch7]

Currently depends on a alpha version of futures-preview, but with std::future now on stable we should get a stable release of futures 0.3 soon. Normally I would say wait on something like this, but #2385 is going to need this change to properly support async ops.

[95th]

Can we temporarily switch to nightly for some time and move the code to async await?

cc @ry

[ry]

Can we temporarily switch to nightly for some time and move the code to async await?

You can do that in a branch :)

Not in master. I don't want to open that can of worms.

[95th]

In that case, given the scale of refactoring we're doing at the moment, I think it is not worth it to maintain another branch. We'll do it when async-await is in stable

[afinch7]

Here is a list of dependencies, and their respective statuses.

• tokio (tokio-executor, tokio-fs, tokio-io, tokio-threadpool) waiting on alpha release meta: update to std::future and release an alpha. tokio-rs/tokio#1201 (using git for now)
  • futures - waiting on stable release (using preview/alpha for now)
  • async-await - waiting on stabilization (using nightly until 1.38.0 release) [Stabilization] async/await MVP rust-lang/rust#62149

Dependent on tokio:

• tokio-process(getting merged into tokio) - waiting on stable release
• hyper - waiting on alpha release (using git for now)
• hyper-rustls - waiting on patch to be started(dependent on
  others)
  • tokio-rustls - working on a patch

I think that is everything let me know if there is something I missed. Also thoughts on runtime?

[afinch7]

I manged to get deno_tcp working, so here are some results so far. I picked the median of 3 runs for both. Don't mind the terrible tail latency. I think that has more to do with my hardware than anything.

This branch:

Running 10s test @ http://127.0.0.1:4500/
  2 threads and 10 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency     0.91ms    5.76ms 102.88ms   98.33%
    Req/Sec    14.77k     1.69k   16.43k    96.00%
  293777 requests in 10.00s, 14.29MB read
Requests/sec:  29369.49
Transfer/sec:      1.43MB

Master:

Running 10s test @ http://127.0.0.1:4500/
  2 threads and 10 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency     0.91ms    5.81ms 104.34ms   98.42%
    Req/Sec    14.55k     1.67k   16.07k    96.00%
  289246 requests in 10.00s, 14.07MB read
Requests/sec:  28920.91
Transfer/sec:      1.41MB

Within margin of error, but still about ~2-3% in favor of this branch.

[ry]

@afinch7 That's good to hear!

[95th]

Here is a list of dependencies, and their respective statuses.

Think most of the stuff can be checked except hyper-rustls (Perhaps use hyper-tls)?

[afinch7]

Here is a list of dependencies, and their respective statuses.

Think most of the stuff can be checked except hyper-rustls (Perhaps use hyper-tls)?

Yes I think most of the dependencies are ready, but async/await has been delayed to 1.39.0 that's really the only thing I'm still waiting on here.

[ry]

Old PR, closing.

We will move to the new futures API, but ideally there would be a stable release of Tokio using this new future API first. We need Tokio to make a stable release using the new Futures API first.