Prevent deadlocks with load interlock and DB lock. #31035
Conversation
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r? @matthewd |
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The test failures seem unrelated to this change (and I've seen them failing on other branches, too). Let me know if that's something I should be trying to take care of as part of this. |
This fixes an issue where competing threads deadlock each other. - Thread A holds the load interlock but is blocked on getting the DB lock - Thread B holds the DB lock but is blocked on getting the load interlock (for example when there is a `Model.transaction` block that needs to autoload) This solution allows for dependency loading in other threads while a thread is waiting to acquire the DB lock. Fixes #31019
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A rebase cleaned up the failures. @matthewd, please let me know if there's anything else I need to do here. |
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This looks perfect, thanks! Great work on the test, too! 👌 |
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Awesome - thanks for you're help, @matthewd! |
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Just opened #31174 for the backport while I was in context. |
Summary
This fixes an issue where competing threads deadlock each other.
Model.transactionblock that needs to autoload)This solution allows for dependency loading in other threads while a thread is waiting to acquire the DB lock.
Other Information
I'm very open to suggestions on naming and location of the new monitor, and also totally alternate approaches if folks have other thoughts.
Fixes #31019