[hotfix] actually send broadcast messages in sequence
- we introduced a fix a long time ago to send broadcast messages in sequence
on the theory that (1) this would jam up signald's concurrency bugs
less and (2) we had observed health checks fail less and transmit
faster when sent in sequence
- however, we did not notice that
broadcastMessage
was only ever
being called with one recipient (presumably to get per-recipient
language choices honored) so we were never actually sending such
messages in sequence
-
@mari has a more comprehensive fix coming in #329 (closed), but until it
lands, here is a small patch to make sure broadcast messages
actually go out in sequence so we can measure if this makes any kind
of difference in perf/reliability