tree ab00ec9ce66f6de7c03149ef869a6f7c7f2a633d
parent 1b7b54cab81d84e6e19117cd00179a22b46b6a86
author Patrick Williams <patrick@stwcx.xyz> 1663858413 -0500
committer Patrick Williams <patrick@stwcx.xyz> 1665747351 -0500

async: handle exceptions and stops

Add support in `context` and `scope` to handle exceptions and stop
conditions:

  * When an unhandled_stop occurs, turn it into an UnhandledStop
    exception.
  * When a `scope`-spawned task throws an exception, save it and cause
    `set_error` on the `scope::empty()`'s Receiver.
  * When anything in the `context` completes with `set_error` propagate
    that out to the caller of `context::run`.
  * If multiple exceptions occur within a `scope`, terminate.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I25285f7ece5c0675864489bbe1345fa8e7afa70c