Fix concurrent database access when deleting orphans #219
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melekes
reviewed
Mar 10, 2020
AdityaSripal
approved these changes
Mar 13, 2020
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When deleting orphans, an orphan node is deleted from the database while the database is being iterated over. This breaks the tm-db contract:
This caused deadlocks and race conditions with the new B-tree based MemDB.
I believe this is an oversight, since all of the other related writes are batched in
snapshotBatchorrecentBatchinstead of writing directly to the database. This change fixes the problem by batching the deletes instead. The tests pass, but I would like a confirmation from someone familiar with this logic.