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kyro46 / assPaintQuestion

!ILIAS 8-Version requires testing! Questiontype that allows free painting on a browsercanvas in ILIAS 4.3 to 8
GNU General Public License v3.0
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Possible race condition when saving learners input #29

Closed kyro46 closed 2 years ago

kyro46 commented 2 years ago

In rare conditions when save/autosave happens closely together, the save routine might encounter a race condition where two solutions are stored in the database for a single user/pass/question at the same time.

kyro46 commented 2 years ago

In existing cases of multiple solutions, the older one might be deleted. Older versions of ILIAS circumvented errors caused by race conditions by simply ignoring everything except the latest submission. But assPaint has a (nowdays unnecessary) loop which encounters an error. The loop will be removed in further refactorings.