Amortize the startup cost of some components

[hubertp]

Pull Request Description

Building Engine, Context, ApplicationConfig and Ydoc was a adding a rather large delay during the initial startup step as all of those were blocking operations.
Moving all of those to the resource initialization step hopes to amortize some of that cost since it can be done in parallel. Had to add a ComponentSupervisor (open for a different name suggestion) to ensure that such delayed components are properly closed on shutdown.

Important Notes

Adding Ydoc has added a visible delay during startup. I'm hoping that we can amortize some of that with this PR:

Now:

and run in parallel:

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  TypeScript,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• Unit tests have been written where possible.

[4e6]

AFAIK it works because the single component initialization is guaranteed by the LockedInitialization implementation.

[hubertp]

Yeah, this is just a precaution in case someone wants to use in a wrong way.

[JaroslavTulach]

Shouldn't we have a benchmark that would verify you actually speed language server initialization up with these changes? Such a benchmark shall not be too different from this one - just different arguments, right?

[Akirathan]

Such a benchmark shall not be too different from this one - just different arguments, right?

@JaroslavTulach That benchmark measure startup only of the engine distribution. Whereas, @hubertp was profiling the startup of language server. I am afraid we don't have any benchmarks for language server yet.

[JaroslavTulach]

@JaroslavTulach That benchmark measure startup only of the engine distribution.

Language server is part of the engine distribution. One just has to use --server option that Runs Language Server.

[Akirathan]

Language server is part of the engine distribution. One just has to use --server option that Runs Language Server.

@JaroslavTulach That is true. However, for it to be useful, one has to also send some requests, at least acquire capability request (?). If you just start language server by simply running something like enso --server ... --root-id ... <all-the-other-necessary-stuff>, without any client connection, are we sure that the language server will start all its components?