Fix concurrency issues with SQLite pooling #32615
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Fixes #25797 Fixes #26016 I identified two race conditions, both caused by splitting state across multiple data structures. In particular, the Semaphore and the two ConcurrentStacks must stay in sync--that is, the Semaphore can let someone get a collection if and only if there is a connection available in the one of the stacks. The fix is to wrap all these things in a single lock. It's possible that we don't need a full lock, but we already have one to protect _collections which can easily be expanded to cover the right areas. Once this lock is used, the semaphore is no longer needed, and the stacks don't need to be concurrent because they are protected by the lock.
AndriySvyryd
approved these changes
Dec 14, 2023
| { | ||
| DisposeConnection(connection); | ||
| DisposeConnection(connection!); |
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Strange that you had to bang here
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Some things are not ideal because of the cross-compile to .NET Framework.
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Fixes #25797
Fixes #26016
I identified two race conditions, both caused by splitting state across multiple data structures. In particular, the Semaphore and the two ConcurrentStacks must stay in sync--that is, the Semaphore can let someone get a collection if and only if there is a connection available in the one of the stacks.
The fix is to wrap all these things in a single lock. It's possible that we don't need a full lock, but we already have one to protect _collections which can easily be expanded to cover the right areas.
Once this lock is used, the semaphore is no longer needed, and the stacks don't need to be concurrent because they are protected by the lock.