[JCS-69] Synchronization Problem in JCSWorker

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: jcs-1.3, jcs-2.0-beta-1
• Fix Version/s: jcs-2.0-beta-1
• Environment: Linux 2.6.28-15-generic #52-Ubuntu SMP Wed Sep 9 10:48:52 UTC 2009 x86_64 GNU/Linux; java version "1.6.0_16"; Java(TM) SE Runtime Environment (build 1.6.0_16-b01); Java HotSpot(TM) 64-Bit Server VM (build 14.2-b01, mixed mode)
• Assignee: Aaron Smuts
• Reporter: Scott Archer
• Created: 15/Oct/09 19:07
• Updated: 01/Apr/15 14:50
• Resolved: 30/Oct/11 18:17

Description

When using the JCSWorker threads lock indefinitely.
I believe the synchronized block in the finally block is synchronizing on and notifying the wrong object.

Once a thread locks it never unlocks.

Class: org.apache.jcs.utils.access.JCSWorker
Method: private Object run( Serializable aKey, String aGroup, JCSWorkerHelper aHelper ) throws Exception

Bad Code (in finally block):
synchronized ( this )

{ aHelper.setFinished( true ); // Wake everyone waiting on us notifyAll(); }

Suggested Fix:
synchronized ( aHelper )

{ aHelper.setFinished( true ); // Wake everyone waiting on aHelper aHelper.notifyAll(); }