[EXLBR-1] Timing bug in rg.apache.excalibur.thread.ThreadControl.join()

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Component/s: Thread
• Environment: Mandrake 9.2 on Compaq Armada E500
• Assignee: Sasvata Chatterjee
• Reporter: Pradeep Krishnan
• Created: 20/Feb/04 05:27
• Updated: 17/Apr/05 00:29
• Resolved: 17/Apr/05 00:29

Description

The ThreadControl implimentation in org.apache.excalibur.thread.impl.DefaultThreadControl has a timing bug in the join() function. There is a small timing window between the time the worker thread has finished executing and before a call to the finish() method of the ThreadControl is made. This can cause the threads waiting on a join(0) to never wake-up.

The patch is simple: instead of delegating the join() to the m_thread, do a wait(). The finish() method of the org.apache.excalibur.thread.impl.DefaultThreadControl does a notifyAll() and that should wake up the calling thread.