GetOrSetAsync for a cacheKey hangs for an infinite time #281
Description
What does the bug do?
GetOrSetAsync call for particular cacheKey sometimes hangs for an infinite time.
I think the reason of the behaviour is this TaskCompletionSource which can be created, for intance, when 2 threads getting value for a first time in parallel (cache miss), and thread A goes to this branch of code , thread B goes to this branch of code, sleeps for a while, and then calls KeyLock.WaitAsync(cacheKey) when the KeyLock is already released by thread A.
Then, Thread B waits for the TaskCompletionSource just created by itself, and from the thread perspective it looks like infinite call of GetOrSetAsync method, and only another thread calling GetOrSetAsync with the same cacheKey can release Thread B from this block.
Not sure, but it looks like even this another thread call won't help if it happens after cacheEntry (created by thread A) is expired.
How can it be reproduced?
In my case it could only be reproduced under (relatively) heavy load.
Environment (if applicable)
- NuGet Package Version: 0.14.0
- .NET Runtime Version: .NET 8
- Operating System: Linux