Does LRUQueryCache#uniqueQueries really needs wrapped by Collections.synchronizedMap?

[vsop-479]

Description

LRUQueryCache#uniqueQueries is wrapped by Collections.synchronizedMap, but we use it under readLock/writeLock.

[jpountz]

It looks like you are right, we could remove the wrapper.

[benwtrent]

@vsop-479 @jpountz maybe my understanding of how LinkedHashMaps work is wrong. But: #13306 (comment)

It seems to me that if multiple readers call get on LinkedHashMap the order will get messed up.

[jpountz]

Argh, of-couse, thank you @benwtrent! I opened a PR so that it's more obvious to readers of this code in the future: #14749.

[vsop-479]

Oh, You are right @benwtrent !