## Motivation
The `tokio_net` resources can be created outside of a runtime due to how tokio
has been used with futures to date. For example, this allows a `TcpStream` to be
created, and later passed into a runtime:
```
let stream = TcpStream::connect(...).and_then(|socket| {
// do something
});
tokio::run(stream);
```
In order to support this functionality, the reactor was lazily bound to the
resource on the first call to `poll_read_ready`/`poll_write_ready`. This
required a lot of additional complexity in the binding logic to support.
With the tokio 0.2 common case, this is no longer necessary and can be removed.
All resources are expected to be created from within a runtime, and should panic
if not done so.
Closes#1168
## Solution
The `tokio_net` crate now assumes there to be a `CURRENT_REACTOR` set on the
worker thread creating a resource; this can be assumed if called within a tokio
runtime. If there is no current reactor, the application will panic with a "no
current reactor" message.
With this assumption, all the unsafe and atomics have been removed from
`tokio_net::driver::Registration` as it is no longer needed.
There is no longer any reason to pass in handles to the family of `from_std` methods on `net` resources. `Handle::current` has therefore a more restricted private use where it is only used in `driver::Registration::new`.
Signed-off-by: Kevin Leimkuhler <[email protected]>
Bring back `split` utility as a free fn instead of a method on
`AsyncRead`. This utility wraps the `stream` in an `Arc` and uses mutual
exclusion to ensure correct access.
Additionally, the specialized `split_mut` fn on TcpStream and UdsStream
is promoted to `split`.
A sealed `net::ToSocketAddrs` trait is added. This trait is not intended
to be used by users. Instead, it is an argument to `connect` and `bind`
functions.
The operating system's DNS lookup functionality is used. Blocking
operations are performed on a thread pool in order to avoid blocking the
runtime.
* net: switch from `log` to `tracing`.
Motivation:
The `tracing` crate implements scoped, structured, context-aware
diagnostics, which can add significant debugging value over unstructured
log messages. `tracing` is part of the Tokio project. As part of the
`tokio` 0.2 changes, I thought it would be good to move over from `log`
to `tracing` in the tokio runtime.
Solution:
This branch replaces the use of `log` in `tokio-net` with
`tracing`. I've tried to leave all the instrumentation points more or
less the same, but modified to use structured fields instead of string
interpolation.
Notes:
I removed the timing in `Reactor::poll` in favor of simply adding a
`#[tracing::instrument]` attribute. Since the generated `tracing` span
will have enter and exit events, a `tracing::Subscriber`
implemementation can use those to record timestamps, and process that
timing data in a much more sophisticated manner than including it in a
log line.
We can add the timestamps back if they're desired.
Signed-off-by: Eliza Weisman <[email protected]>
Kevin Leimkuhler