#15975: semantics of concurrent program depends on -O level, -f[no-]omit-yields -------------------------------------+------------------------------------- Reporter: j.waldmann | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Research | needed Component: Runtime System | Version: 8.6.2 Resolution: | Keywords: Operating System: Linux | Architecture: x86_64 Type of failure: Incorrect result | (amd64) at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by j.waldmann): (based on https://mail.haskell.org/pipermail/haskell- cafe/2018-November/130280.html ) So my implicit assumption was that a run of the transaction manager (because "atomically") is also a yield - but this example shows that it isn't. If this is indeed the case, then this deserves to be mentioned in the documentation of Control.Concurrent.STM ? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15975#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler