[Pool-425] [Pool-426] GenericObjectPool addObject does not respect maxIdle

[rajucomp]

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Problem/Bug Description

When the pool's addObject() method is called to pre-load the pool with idle objects, the current implementation only validates against maxTotal (the maximum total number of objects that can exist in the pool, including both active and idle objects) to prevent exceeding the configured maximum. However, it does not validate against maxIdle (the maximum number of idle objects allowed in the pool).

This validation gap can result in the pool creating more idle objects than the configured maxIdle limit allows, which violates the pool's configuration contract.

Fix

The fix ensures both maxTotal and maxIdle values are properly compared, and the pool uses the minimum of these two values as the effective limit when deciding whether to add new objects. This ensures the pool respects whichever limit is lower and prevents violating either configuration constraint.

Related JIRA Issue

This fix addresses POOL-425: GenericObjectPool addObject does not respect maxIdle

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Checklist

• Bug fix properly validates against both maxTotal and maxIdle
• Unit tests added for single-threaded scenarios
• Concurrent tests added for multi-threaded scenarios
• All existing tests pass
• Code follows project conventions and style
• No breaking changes to public API

[rajucomp]

@garydgregory @psteitz Requesting critical review for the fix for POOL-425. Thanks!

[ruanLN]

This will cause issues if maxIdle is set to zero, making it impossible to create new objects in the pool.

Since the method is private we can verify it is only used during the borrow, where it is not added to the idle objects, and on addObject, where it is.

the addObject method should be checking the idle object limit isn't being crossed.