Daoyuan Li fa419b3e4c
fix(goal): stop continuation_count double-bump in thread_changed_before_continuation stand-down (#4199)
_prepare_goal_continuation_input calls the same _persist closure twice
with the identical next_count in one evaluation cycle: once to commit
the real continuation, and again to record a thread_changed_before_continuation
stand-down if a race is detected right after that commit. The second
call re-passed continuation_count=next_count, so #4088's defensive
max(continuation_count, current_count + 1) guard saw the first call's
own write as a "current_count" bump and added another +1 on top of it -
silently consuming 2 units of the continuation budget for a cycle that
delivered zero actual continuations. #4088's guard is correct for the
independent-concurrent-continuations race it targets; this is a
separate call site incorrectly re-triggering that same guard against
itself.

The second _persist call no longer passes continuation_count, matching
every other stand-down call site in this function - the count was
already correctly committed by the first call.

Adds a regression test mirroring the existing
thread_changed_after_evaluation race test's checkpointer-wrapper
technique, since this sibling branch had zero prior coverage.
2026-07-15 20:21:04 +08:00
..