LockService hangs during concurrent access (tryLock/tryLock(timeout)/lock/unlock) --------------------------------------------------------------------------------- Key: JGRP-1660 URL: https://issues.jboss.org/browse/JGRP-1660 Project: JGroups Issue Type: Bug Affects Versions: 3.2.4, 3.3.3 Environment: Intel(R) Core(TM) i5-2310 CPU @ 2.90GHz 6GB RAM Windows 7 JRE 1.6.31 Reporter: Architect SoftWeb.ISD Assignee: Bela Ban Fix For: 3.5 Attachments: bla2.java, lock.xml, lock.xml, LockServiceStabilityTestCase.java, LockServiceStabilityTestCase.java, LockServiceStabilityTestCase.java, lockservice_stability_testcase.jar We have rather simple test that starts some amount of threads which in turn simultaneously obtain lock through LockService#getLock then perform lock and unlock. Each thread works during some time. After couple of seconds of work some threads just hang up in Locking$ClientLock(Object).wait() called indirectly from LockService$LockImpl.tryLock(). Here is stack trace: Thread [Thread-ClientImitation-1] (Suspended) Object.wait(long) line: not available [native method] Locking$ClientLock(Object).wait() line: 485 Locking$ClientLock.acquireTryLock(long, boolean) line: 1010 Locking$ClientLock.tryLock() line: 896 CENTRAL_LOCK(Locking).down(Event) line: 152 ProtocolStack.down(Event) line: 1025 JChannel.down(Event) line: 718 LockService$LockImpl.tryLock() line: 102 LockServiceStabilityTestCase$ClientImitation.run() line: 167 Thread.run() line: 662