[POOL-120] maxActive can be exceeded by one

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.2
• Fix Version/s: 1.4
• Assignee: Unassigned
• Reporter: Phil Steitz
• Created: 06/Jan/08 21:37
• Updated: 12/Sep/10 17:43
• Resolved: 07/Jan/08 02:40

Description

For GenericObjectPool, when numIdle > 0 and the idle object evictor is set to run (timeBetweenEvictionRunsMillis > 0), a race condition can occur between the Evictor and a borrowing thread, wherein the Evictor initiates a makeObject in ensureMinIdle and before the newly created object is placed in the pool, the borrowing thread initiates another makeObject that makes the number of instances in circulation = maxActive + 1.

This issue does not affect pool 1.3, since addObject is syncrhonized in that version. It does affect 1.4-RC1 (unreleased snapshot) and the code currently in the 1.4 release branch.