* Add a new `windows::CtrlBreak` struct which wil represent a stream of
CTRL_BREAK_EVENT signals on Windows systems
* The `windows::Event` type is no longer publicly accessible and is
replaced by using `CtrlC` or `windows::CtrlBreak`.
[breaking-change]
* Add a new `CtrlC` struct which will represent a stream of SIGINT
signals on Unix or the CTRL_C event on Windows
* `CtrlC` implements `Stream<Output = ()>` rather than `IoSteam` as
previously
Migrate to std::futures and the futures 0.3 preview and use async/await
where possible
**Breaking change:** the IoFuture and IoStream definitions used to refer
to Box<dyn Future> and Box<dyn Stream>, but now they are defined as
Pin<...> versions which are technically breaking.
No other breaking or functional changes have been made
Today the Unix and Windows implementations have similar yet differing
implementations of hooking into OS events and propagating them to any
listening futures. Rather than re-implement the same behavior two
different ways, we should factor out any commonality into a shared
module and keep the Unix/Windows modules focused solely on OS
integrations.
Reusing the same implementation across OS versions also allows for more
consistent behavior between platforms, which also makes squashing bugs
much easier.
This change introduces the `registry` module which handles creating and
initializing a global map of signals/events and their registered
listeners. Each OS specific module is expected to implement the OS hooks
which delegate to invoking the registry module's methods for
distributing the event notifications.
# Use registry module for Windows implementation
Note this still uses the same architecture as previously: a driver task
is spawned by the first registered event, and that task is responsible
for delivering any events to registered futures. (If that first event
loop goes away, all events will deadlock). A solution to this issue will
be explored at a later time.
* Don't use tokio-core any more for tests. That one brings tokio from
crates.io instead of the current workspace and two versions of that
don't want to cooperate.
* Guard unix-specific examples on windows.
* Leave CI setup to top-level directory.
