This is a does-one-thing module for making it easy to start or to adopt goroutines that need to respond gracefully to a soft termination request and then being able to wait for them to finish. Every time I've written a network service or other program that has some task-like pattern in it, I've wound up implementing some subset of the functionality below.
Supported use-cases:
* accept() / poll() type APIs
* Adopting already-spawned goroutines (e.g. from http.Server)
* Channel-based notifications
* Deferred cleanups
* Nested task groups
* Support for `runtime/trace` or other Context-creating modules