Currently, `tokio::spawn` matched the `spawn` function from futures 0.2.
However, this adds additional ergonomic overhead and removes the ability
to spawn from a drop fn. See rust-lang-nursery/futures-rs#830.
This patch switches the behavior to access the thread-local variable
referencing the default executor directly in the `spawn` function.
This patch makes a significant change to how I/O resources bind to a
reactor. Currently, an I/O resource (TCP, UDP, PollEvented) will bind
itself with a reactor upon creation.
First, some history.
Originally, tokio-core required that I/O resources be explicitly
associated with a reactor upon creation by passing in a `&Handle`. Tokio
reform introduced a default reactor. If I/O resources do not specify a
reactor upon creation, then the default reactor is used.
However, futures tend to favor being lazy. Creating a future should do
no work, instead it is defining a computation to be performed once the
future is executed. Binding an I/O resource with a reactor on creation
goes against this pattern.
This patch fixes this by allowing I/O resources to lazily bind to a
reactor. An explicit `&Handle` can still be used on creation, but if no
reactor is specified, then the default reactor is used. However, this
binding happens during execution time (read / write) and not creation.
This patch is an intial implementation of the Tokio runtime. The Tokio
runtime provides an out of the box configuration for running I/O heavy
asynchronous applications.
As of now, the Tokio runtime is a combination of a work-stealing thread
pool as well as a background reactor to drive I/O resources.
This patch also includes tokio-executor, a hopefully short lived crate
that is based on the futures 0.2 executor RFC.
* Implement `Park` for `Reactor`
This enables the reactor to be used as the thread parker for executors.
This also adds an `Error` component to `Park`. With this change, a
`Reactor` and a `CurrentThread` can be combined to achieve the
capabilities of tokio-core.
std's `Incoming` iterator yields `TcpStream` instances. This patch
updates the `Incoming` future to match this signature.
This changes the yielded value from `(TcpStream, SocketAddr)` ->
`TcpStream`.
This commit removes the `Handle` argument from the following constructors
* `TcpListener::bind`
* `TcpStream::connect`
* `UdpSocket::bind`
The `Handle` argument remains on the various `*_std` constructors as they're
more low-level, but this otherwise is intended to set forth a precedent of by
default not taking `Handle` arguments and instead relying on the global
`Handle::default` return value when necesary.
This commit starts to add support for a global event loop by adding a
`Handle::default` method and implementing it. Currently the support is quite
rudimentary and doesn't support features such as shutdown, overriding the return
value of `Handle::default`, etc. Those will come as future commits.