* send_message should not return an error

* Apply suggestions from code review

Co-authored-by: Peter Goodspeed-Niklaus <[email protected]>

* s/send_logging_error/send_and_log_error

Co-authored-by: Peter Goodspeed-Niklaus <[email protected]>

* Change SpawnedSubsystem type to log subsystem errors

* Remove clone

* Make `AllSubsystems` usage easier in tests

This makes the usage of `AllSubsystems` easier in tests by introducing
new methods.

- `dummy` initializes `AllSubsystems` with all systems set to dummy
- `replace_*` to replace any subsystem

Besides that this pr adds a `ForwardSubsystem` that is also useful for
tests. This subsystem will forward all incoming messages to the given channel.

* Update node/overseer/src/lib.rs

Co-authored-by: Andronik Ordian <[email protected]>

* Update node/subsystem/src/lib.rs

Co-authored-by: Andronik Ordian <[email protected]>

* Update node/subsystem/src/lib.rs

Co-authored-by: Andronik Ordian <[email protected]>

* Move ForwardSubsystem and add a test

* Break some lines

Co-authored-by: Andronik Ordian <[email protected]>

* WIP

* The initial implementation of the collator side.

* Improve comments

* Multiple collation requests

* Add more tests and comments to validator side

* Add comments, remove dead code

* Apply suggestions from code review

Co-authored-by: Peter Goodspeed-Niklaus <[email protected]>

* Fix build after suggested changes

* Also connect to the next validator group

* Remove a Future impl and move TimeoutExt to util

* Minor nits

* Fix build

* Change FetchCollations back to FetchCollation

* Try this

* Final fixes

* Fix build

Co-authored-by: Peter Goodspeed-Niklaus <[email protected]>

* jobs: don't early exit when there are no jobs

* utils: fix merged test

* utils: less verbose

* utils: add an assert subsystem is running

* utils: use TimeoutExt from test-helpers

* test-helpers: use TimeoutExt

* start sketching out a collation generation subsystem

* invent a basic strategy for double initialization

* clean up warnings

* impl util requests from runtime assuming a context instead of a FromJob sender

* implement collation generation algorithm from guide

* update AllMessages in tests

* fix trivial review comments

* remove another redundant declaration from merge

* filter availability cores by para_id

* handle new activations each in their own async task

* update guide according to the actual current implementation

* add initialization to guide

* add general-purpose subsystem_test_harness helper

* write first handle_new_activations test

* add test that handle_new_activations filters local_validation_data requests

* add (failing) test of collation distribution message sending

* rustfmt

* broken: work on fixing sender test

Unfortunately, for reasons that are not yet clear, despite the public key
and checked data being identical, the signer is not producing an identical
signature. This commit produces this output (among more):

signing with  Public(c4733ab0bbe3ba4c096685d1737a7f498cdbdd167a767d04a21dc7df12b8c858 (5GWHUNm5...))
checking with Public(c4733ab0bbe3ba4c096685d1737a7f498cdbdd167a767d04a21dc7df12b8c858 (5GWHUNm5...))
signed payload:  [4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 10, 0, 0, 0, c7, e5, c0, 64, 7a, db, fe, 44, 81, e5, 51, 11, 79, 9f, a5, 63, 93, 94, 3c, c4, 36, c6, 30, 36, c2, c5, 44, a2, 1b, db, b7, 82, 3, 17, a, 2e, 75, 97, b7, b7, e3, d8, 4c, 5, 39, 1d, 13, 9a, 62, b1, 57, e7, 87, 86, d8, c0, 82, f2, 9d, cf, 4c, 11, 13, 14]
checked payload: [4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 10, 0, 0, 0, c7, e5, c0, 64, 7a, db, fe, 44, 81, e5, 51, 11, 79, 9f, a5, 63, 93, 94, 3c, c4, 36, c6, 30, 36, c2, c5, 44, a2, 1b, db, b7, 82, 3, 17, a, 2e, 75, 97, b7, b7, e3, d8, 4c, 5, 39, 1d, 13, 9a, 62, b1, 57, e7, 87, 86, d8, c0, 82, f2, 9d, cf, 4c, 11, 13, 14]

* fix broken test

* collation function returns commitments hash

It doesn't look like we use the actual commitments data anywhere, and
it's not obvious if there are any fields of `CandidateCommitments`
not available to the collator, so this commit just assigns them the
entire responsibility of generating the hash.

* add missing overseer impls

* calculating erasure coding is polkadot's responsibility, not cumulus

* concurrentize per-relay_parent requests

* subsystem: add spawn_blocking to SubsystemContext

* candidate-validation: use spawn_blocking for exhaustive tasks

Closes #1237

* break out subsystem-util and subsystem-test-helpers into individual crates

* cause all packages to check successfully

* get conclude signal working properly; don't allocate a vector

* wip: add test suite / example / explanation for using utility subsystem

Unfortunately, the test fails right now for reasons which seem
very odd. Just have to keep poking at it.

* explicitly import everything

* fix subsystem-util test

The root problem here was two-fold:

- there was a circular dependency from subsystem -> test-helpers/subsystem ->
  subsystem
- cfg(test) doesn't propagate between crates

The solution: move the subsystem test helpers into a sub-module
within subsystem. Publicly export them from the previous location
so no other code breaks.

Doing this has an additional benefit: it ensures that no production
code can ever accidentally use the subsystem helpers, as they are compile-
gated on cfg(test).

* fully commit to moving test helpers into a subsystem module

* add some more tests

* get rid of log tests in favor of real error forwarding

It's not obvious whether we'll ever really want to chase down
these errors outside a testing context, but having the capability
won't hurt.

* fix issue which caused test to hang on osx

* only require that job errors are PartialEq when testing

also fix polkadot-node-core-backing tests

* get rid of any notion of partialeq

* rethink testing

Combine tests of starting and stopping job: leaving a test executor
with a job running was pretty clearly the cause of the sometimes-hang.

Also, add a timeout so tests _can't_ hang anymore; they just fail
after a while.

* rename fwd_errors -> forward_errors

* warn on error propagation failure

* fix unused import leftover from merge

* derive eq for subsystemerror

* Use SpawnNamed instead of Spawn in Overseer

* reexport SpawnNamed and fix doc tests

* Fix deps

* network bridge skeleton

* move some primitives around and add debug impls

* protocol registration glue & abstract network interface

* add send_msgs to subsystemctx

* select logic

* transform different events into actions and handle

* implement remaining network bridge state machine

* start test skeleton

* make network methods asynchronous

* extract subsystem out to subsystem crate

* port over overseer to subsystem context trait

* fix minimal example

* fix overseer doc test

* update network-bridge crate

* write a subsystem test-helpers crate

* write a network test helper for network-bridge

* set up (broken) view test

* Revamp network to be more async-friendly and not require Sync

* fix spacing

* fix test compilation

* insert side-channel for actions

* Add some more message types to AllMessages

* introduce a test harness

* add some tests

* ensure service compiles and passes tests

* fix typo

* fix service-new compilation

* Subsystem test helpers send messages synchronously

* remove smelly action inspector

* remove superfluous let binding

* fix warnings

* Update node/network/bridge/src/lib.rs

Co-authored-by: Peter Goodspeed-Niklaus <[email protected]>

* fix compilation

Co-authored-by: Peter Goodspeed-Niklaus <[email protected]>