modules/pubsub: Add simple pubsub module
This implements a module for publishing events to a set of subscribed
callbacks. The design is initially simple, allowing a limited set of
callbacks and a 1-deep event queue. Subscribers are run from a work
queue context.
Change-Id: Ifb30652b0f630585e8cbc6bcfe5c1fb5026f0a19
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/showcase/rp2/+/220251
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Commit-Queue: Alexei Frolov <frolv@google.com>
Reviewed-by: Taylor Cramer <cramertj@google.com>
3 files changed
