meta: update to std::future and release an alpha.

[carllerche]

This issue tracks the progress of updating Tokio to use std::future.

Crates to update

• tokio-codec (codec: update to std::future #1189).
• tokio-fs (fs: update to std::future #1192).
• tokio-signal (signal: update to std::future #1193).
• tokio-threadpool (threadpool: update to std::future #1200).
• tokio-tls (tls: update to std::future #1194).
• tokio-udp (udp: update to std::future #1195).
• tokio-uds (uds: update to std::future #1196).

Examples

The examples should be updated to idiomatic async / await syntax.

• blocking
• chat-combinator-current-thread
• chat-combinator
• chat
• connect
• echo-udp
• echo
• hello_world
• manual-runtime
• print_each_packet
• proxy
• tinydb
• tinyhttp
• udp-client
• udp-codec

Additional functionality

Besides requiring crates to have transitioned to std::future, some examples are blocked on additional functionality being added.

• I/O helpers (tokio: introduce I/O utility helpers #1203).

Alpha release

The first alpha release will happen once the examples have been updated.

[rubdos]

The first alpha release will happen once the examples have been updated.

I'll take some (if not all) examples on me. Feel free to ping me on Gitter, merge request incoming.

[archseer]

Note: while the tokio-threadpool crate was updated, the tokio crate itself is currently hardcoded to current_thread runtime. We should probably open an issue for that.

I tried porting the required modules but couldn't quite figure out what the updated code should look like.

[carllerche]

@archseer good call.

[CryZe]

Is there a reason AsyncRead and AsyncWrite are not just reexported from futures? These are causing incompatibility problems for me. If it's not intentional, I'll send a PR.

[seanmonstar]

@CryZe so far, that's been intentional. There's been desire to explore alternate method signatures.

What compatibility issues are there? With other libraries?

[carllerche]

@archseer bringing back the multi-threaded runtime: #1280

[archseer]

Thanks! With this I can now almost get things running (still tackling compat stuff). What I did notice though is that tokio-uds pulls in the tokio v0.1 crates because the dependency on it in tokio doesn't specify path ="../tokio-uds" I think:

https://github.com/tokio-rs/tokio/blob/master/tokio/Cargo.toml#L87

[rubdos]

FYI, proxy example at 914038e (rubdos/tokio/proxy-example) works now (with async fn accept()), but needs futures-preview. Feel free to pick that from my fork.

EDIT: accidentally pasted wrong commit. EDIT EDIT: accidentally thought to have pasted the wrong commit.

[rubdos]

Seems like all other examples depend on some decision like #1225, since some kind of Stream trait is basically required for nice async examples.