* Replace unbounded channels with bounded ones.
To remove the unbounded channels used for communicating with node tasks
an API similar to `futures::Sink` is used, i.e. sending is split into a
start and complete phase. The start phase returns `StartSend` and first
attempts to complete any pending send operations. Completing the send
means polling until `Poll::Ready(())` is returned.
In addition this PR has split the `handled_node_tasks` module into
several smaller ones (cf. `nodes::tasks`) and renamed some types:
- `nodes::handled_node_tasks::NodeTask` -> `nodes::tasks::task::Task`
- `nodes::handled_node_tasks::NodeTaskInner` -> `nodes::tasks::task::State`
- `nodes::handled_node_tasks::NodeTasks` -> `nodes::tasks::Manager`
- `nodes::handled_node_tasks::TaskClosedEvent` -> `nodes::tasks::Error`
- `nodes::handled_node_tasks::HandledNodesEvent` -> `nodes::tasks::Event`
- `nodes::handled_node_tasks::Task` -> `nodes::tasks::TaskEntry`
- `nodes::handled_node_tasks::ExtToInMessage` -> `nodes::tasks::task::ToTaskMessage`
- `nodes::handled_node_tasks::InToExtMessage` -> `nodes::tasks::task::FromTaskMessage`
* `take_over_to_complete` can be an `Option`.
Since it is always holding just a single pending message.
* `send_event_to_complete` can be an `Option`.
* Update core/src/nodes/tasks/manager.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Update core/src/nodes/tasks/manager.rs
Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>
* Add comments to explain the need to flush sends ...
of take-over and event messages delivered over Sinks.
