`GossipEngine` spawns two tasks, one for a periodic tick, one to forward
messages from the network to subscribers. These tasks hold an `Arc` to a
`GossipEngineInner`.
To reduce the amount of shared ownership (locking) this patch integrates
the two tasks into a `Future` implementation on the `GossipEngine`
struct. This `Future` implementation can now be called from a single
owner, e.g. the `finality-grandpa` `NetworkBridge`.
As a side effect this removes the requirement on the `network-gossip`
crate to spawn tasks and thereby removes the requirement on the
`finality-grandpa` crate to spawn any tasks.
This is part of a greater effort to reduce the number of owners of
components within `finality-grandpa`, `network` and `network-gossip` as
well as to reduce the amount of unbounded channels. For details see
d9837d7dd, 5f80929dc and 597c0a6c4.
These are a few changes I missed during the refactoring.
1. Initialization issue and boilerplate
Most importantly: part of the `Configuration` initialization was done in `sc_cli::init`. This means the user can not benefit from this initialization boilerplate if they have multiple `Configuration` since `sc_cli::init` can only be called once.
2. Boilerplate for `VersionInfo` and `Configuration`
I'm also answering to the critic of @bkchr on the initialization using version: https://github.com/paritytech/substrate/pull/4692/files/bea809d4c14a2ede953227ac885e3b3f9771c548#r372047238 This will allow initializing a `Configuration` and provide the version by default.
3. Loading the `chain_spec` explicitly
In the past it was done automatically but in some cases we want to delay this. I moved the code to `Configuration.load_spec()` so it can be called later on. `chain_spec` can also be written directly to the `Configuration` without using this `load_spec` helper.
4. [deleted]
5. Fixing issue that prevents the user to override the port
In the refactoring I introduced a bug by mistake that could potentially prevent the CLI user to override the ports if defaults where provided for these ports (only on cumulus).
6. Change task_executor from Box to Arc
This is useful for cumulus where we have 2 nodes with 2 separate Configuration that need to spawn tasks to the same runtime.
7. Renamed TasksExecutorRequired to TaskExecutor
For consistency.
This is related to https://github.com/paritytech/cumulus/issues/24
This is the continuation (and hopefully the end of) #4692
* Restructure node-template so it is clear that node, runtime, and pallets are separated
* Separating to mock and tests
* restructuring runtime to top-level
* updated release script
* updated Cargo.lock
Nikolay Volf