Fix serial runner cancellation #804
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Nice, will take a deeper look early next week 💯 |
pblazej
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Oct 3, 2025
| // Wait for the previous task to complete, but cancel it if needed | ||
| if let previousTask, !Task.isCancelled { | ||
| // Always wait for the previous task to maintain serial ordering | ||
| if let previousTask { |
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I'm just wondering what would happen if we move this wait before Task (essentially "blocking" run)?
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NVM, it just breaks the assumptions made in the 3rd test case 👍
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pblazej
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Oct 6, 2025
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I rebased it onto main as my test branch needs more work 👍
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Problem
The testSerialRunnerCancel() test was failing with the counter ending up negative (-1, -8, etc.) instead of the expected 0, indicating a race condition.
Root Cause
The condition !Task.isCancelled was causing cancelled tasks to skip waiting for the previous task to complete. This broke the serial execution guarantee, allowing multiple blocks to run concurrently and causing unsynchronized access to the shared counter.
Fix
Removed the !Task.isCancelled condition to ensure all tasks wait for the previous task, even when cancelled. This maintains the serial ordering guarantee that the actor is designed to provide.