Changes Report

Release History

Version Date Description
1.5 TBD TBD
1.4 2008-01-15 This is a maintenance release including numerous bug fixes. This release is source and binary compatible with version 1.3 of commons pool, but there are some behavior changes introduced to resolve bugs, remove ambiguity or improve robustness. Among these are the change in default behavior of GenericObjectPool and GenericKeyedObjectPool from FIFO back to LIFO queues (as in 1.2 and earlier). The LIFO/FIFO behavior is now configurable. Some of the extra synchronization included in version 1.3 was removed / refactored to improve performance. The javadoc has also been made more complete and explicit. See the detailed list of changes below for specifics on fixed bugs and behavior changes in Commons Pool 1.4. This version of Commons Pool depends only on JDK version 1.3 or higher. Classes implementing pools are all intended to be threadsafe.
1.3 2006-04-06 1.x bugfix release
1.2 2004-06-07 bugfixes
1.1 2003-10-20
1.0.1 2002-08-12
1.0 2002-05-04


Release 1.5 - TBD

Type Changes By

Release 1.4 - 2008-01-15

Type Changes By
fix sandymac
fix Changed StackKeyedObjectPool to discard stalest, not freshest, idle object when maxSleeping is reached. sandymac
fix Allowed blocked threads in GenericObjectPool borrowObject to be interrupted. Fixes POOL-102 . Thanks to John Sumsion. psteitz
fix Fixes POOL-86 . psteitz
fix Changed the default setting for Config.softMinEvictableIdleTimeMillis to GenericObjectPool.DEFAULT_SOFT_MIN_EVICTABLE_IDLE_TIME_MILLIS (was being incorrectly defaulted to DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS). Fixes POOL-110 . Thanks to Alexander Pogrebnyak. psteitz
fix Added a wrapper for the shared idle object eviction timer for all pools. The wrapper class wraps the Timer and keeps track of how many pools are using it. If no pools are using the timer, it is canceled. This prevents a thread being left running which, in application server environments, can lead to memory leaks and/or prevent applications from shutting down or reloading cleanly. Fixes POOL-97 . Thanks to Mark Thomas. psteitz
fix Reduced synchronization in GenericObjectPool, GenericKeyedObjectPool. Factory method activations within synchronized blocks were causing performance problems in DBCP and other applications where factory methods could block. Fixes both POOL-93 and POOL-108. Fixes POOL-93 . Thanks to Mark Thomas. psteitz
fix Made _testOnBorrow, _testOnReturn volatile and removed synchronization in associated getters and setters in GenericObjectPool, GenericKeyedObjectPool. Made getNumIdle synchronized in StackKeyedObjectPool. Fixes POOL-113 . psteitz
fix Fixed an error in the GenericKeyedObjectPool constructor that takes a Config instance as a parameter. The minIdle setting in the Config was being ignored by the constructor. Fixes POOL-116 . psteitz
fix Made behavior on instance validation failure consistent across pools, eliminating possible infinite loops in StackObjectPool, StackKeyedObjectPool, SoftReferenceObjectPool when factory fails to create valid objects. Fixes POOL-117 .
update When no factory has been defined, addObject now throws IllegalStateExecption instead of NullPointerException for all pools. sandymac
update SoftReferenceObjectPool. Improved the accuracy of getNumIdle by "pruning" references to objects that have been garbage collected. sandymac
update GenericObjectPool, GenericKeyedObjectPool, SoftReferenceObjectPool, StackObjectPool. Eliminated IllegalStateExceptions when the following operations are attempted on a closed pool: getNumActive, getNumIdle, returnObject, invalidateObject. In each case, the operation is allowed to proceed, reporting the state of the pool that is being shut down, or destroying objects returning to the closed pool. sandymac
update StackObjectPool, SoftReferenceObjectPool, GenericKeyedObjectPool. Allowed borrowObject to continue (either examining additional idle instances or with makeObject) when an exception is encountered activating an idle object instead of propagating the exception to the client. Also made addObject propagate (not swallow) exceptions when passivating newly created instances. sandymac
update StackKeyedObjectPool. Added validation check for objects returned from borrowObject. psteitz
update BaseObjectPool, BaseKeyedObjectPool. Instead of throwing UnsupportedOperationException, the base class implementations of getNumIdle and getNumActive return negative values. The base implementation of close in BaseObjectPool no longer throws IllegalStateException when invoked on an already closed pool. sandymac

Release 1.3 - 2006-04-06

Type Changes By
fix A large number of bug fixes. See release notes for changes.

Release 1.2 - 2004-06-07

Type Changes By
fix dirkv
fix dirkv

Release 1.1 - 2003-10-20

Type Changes By
fix A lot of corner cases were fixed
fix Performance improvement by optimizing pool synchronization, the critical code paths were optimized by reducing pool synchronization but we also added more synchronization where needed
fix New minIdle feature: the minimum number of objects allowed in the pool before the evictor thread (if active) spawns new objects. (Note no objects are created when: numActive + numIdle >= maxActive)
fix New maxTotal feature: a cap on the total number of instances controlled by a pool. Only for GenericKeyedObjectPool where maxActive is a cap on the number of active instances from the pool (per key).
fix UML Class and sequence diagrams
fix See bugzilla for more changes

Release 1.0.1 - 2002-08-12

Type Changes By
fix No change log available.

Release 1.0 - 2002-05-04

Type Changes By
add No change log available.