Keep semaphore slots held while blocked jobs are enqueued in concurrency test - #776
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wintan1418 wants to merge 1 commit into
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Keep semaphore slots held while blocked jobs are enqueued in concurrency test#776wintan1418 wants to merge 1 commit into
wintan1418 wants to merge 1 commit into
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…ncy test "run several jobs over the same record limiting concurrency" claims all three semaphore slots with jobs A, B and C, then enqueues D-H expecting all five to block. A and B only paused for 0.5 seconds, so on a slow CI runner they could finish while D-H were still being inserted, freeing a slot that let some of them run instead of blocking and failing the +5 BlockedExecution assertion. Give A and B enough pause to outlive the enqueue window, and bump C accordingly so it still saves last. Related to rails#602
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Related to #602
Problem
ConcurrencyControlsTest#test_run_several_jobs_over_the_same_record_limiting_concurrencyis one of the most frequent CI flakes at the moment — it failed standalone on recentmainruns (e.g. the run for 7f59932) and on unrelated PR runs, always on the same assertion:The test claims all three semaphore slots with jobs A, B and C, waits until the three are claimed, then enqueues D–H expecting all five to become
BlockedExecution. A and B only pause for 0.5s — and that clock starts as soon as they're claimed, before the wait even returns. On a slow runner, by the time the five D–Hperform_laterinserts complete, A or B has already finished and released a semaphore slot, so one of D–H claims it instead of blocking, and the+5assertion comes up short.Fix
Give A and B enough pause (1.5s) to still be holding their slots while D–H are being enqueued, and bump C (3s → 4s) so it keeps finishing well after everything else, preserving the test's final
["C"]assertion. The constraint is now also documented in the test comment.Adds ~1s to the test's runtime in exchange for tripling the margin on the race window.
Testing
Ran the test 6 consecutive times on MySQL plus the full
concurrency_controls_test.rbfile — all green.