graphql-engine/server/src-lib/Hasura/GraphQL/Execute/LiveQuery
Vamshi Surabhi c52bfc540d
More robust forking, exception safety. Closes #3768 (#3860)
This is the result of a general audit of how we fork threads, with a
detour into how we're using mutable state especially in websocket
codepaths, making more robust to async exceptions and exceptions
resulting from bugs.

Some highlights:
- use a wrapper around 'immortal' so threads that die due to bugs are
  restarted, and log the error
- use 'withAsync' some places
- use bracket a few places where we might break invariants
- log some codepaths that represent bugs
- export UnstructuredLog for ad hoc logging (the alternative is we
  continue not logging useful stuff)

I had to timebox this. There are a few TODOs I didn't want to address.
And we'll wait until this is merged to attempt #3705 for
Control.Concurrent.Extended
2020-03-05 23:29:26 +05:30
..
Options.hs Add request timings and count histograms to telemetry. Closes #3552 2020-02-03 18:50:10 -06:00
Plan.hs fix few bugs related to nested insert returning (fix #3609, #3642, #3271) (#3618) 2020-02-04 21:04:17 +05:30
Poll.hs More robust forking, exception safety. Closes #3768 (#3860) 2020-03-05 23:29:26 +05:30
State.hs More robust forking, exception safety. Closes #3768 (#3860) 2020-03-05 23:29:26 +05:30
TMap.hs Multiplex all subscriptions, grouping them by their resolved SQL query 2019-09-16 22:00:46 -05:00