[MDEV-23234] move MDL from THD to st_transaction Created: 2020-07-20 Updated: 2022-04-25 |
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| Status: | Open |
| Project: | MariaDB Server |
| Component/s: | Locking |
| Fix Version/s: | None |
| Type: | Task | Priority: | Major |
| Reporter: | Sergei Golubchik | Assignee: | Vladislav Vaintroub |
| Resolution: | Unresolved | Votes: | 0 |
| Labels: | None | ||
| Issue Links: |
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| Description |
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MDL belongs to a transaction, not to a connection. For example, when a transaction is moved to a different thd, MDLs should be moved too. Problem, what if a connection owns more than one open transaction and they have conflicting lock requests? It cannot wait on itself, so deadlock detector has to be able to detect a loop right away. |