commit c75fe7d73b0629e985c171c64d14da21933af73c
author Gary Bressler <geb@google.com> Thu Oct 10 21:20:36 2024 +0000
committer CQ Bot <fuchsia-internal-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Oct 10 21:20:36 2024 +0000
tree 80cd1e584d736bf8929d49127c3b6481c53bec28
parent 5d3d1ef53907777ba8b4420ea305963865ea8f6b

[component_manager] More extensible framework for builtin components

component_manager has a builtin runner which is used for running
"builtin components", i.e. components whose source code lives in
component manager itself. elf_runner is one (and the only) builtin
component today.

For microfuchsia, we would like to run shutdown-shim and devfs in
component manager as builtin components as well. It turns out though
that the current implementation of builtin runner is a bit inflexible
for expanding to more components.

To this end, this change is a refactor which does the following:

- Introduces a [BuiltinProgram] type that represents the state of a builtin
  program. As one of its arguments, [BuiltinProgram] contains a
  [BuiltinProgramFn], which is a callback that runs the builtin
  component's code.
- Make the ABI for builtin components more similar to non-builtins.
  Builtin components accept a subset of procargs, including namespace,
  out dir, lifecycle channel, etc. This will facilitate porting
  non-builtin components to builtins.
- [BuiltinProgram] has a universal [Controller] implementation which
  integrates with the Lifecycle control channel.
- Refactor elf_runner to use [BuiltinProgram]. elf_runner now uses the
  Lifecycle control channel instead of its own Controller implementation.
- builtin_runner now supports dependency injection for tests. Unit tests can
  bring along their own builtin components.

Fixed: 372527480
Change-Id: Ic8a24d2cd9d7da05c8305572539fb932f054689f
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1134697
Commit-Queue: Gary Bressler <geb@google.com>
Reviewed-by: Claire Gonyeo <cgonyeo@google.com>