Hi,
I encounter the same problem too.
My scenario is 20 concurrent users accessing the same block of code.
Here's the snapshot of the source code:
Execution execution = execService.findExecutionById(processInstanceId);
ProcessInstance rootInstance = getRootProcessInstance(execution);
String rootInstanceId = rootInstance.getId();
execution = execService.signalExecutionById(processInstanceId, variables);
boolean rootExecutionCompleted = null == execService.findExecutionById(rootInstanceId);
It's run under Microsoft Windows XP SP2, SQL Server 2008, JBPM4, and Hibernate 3.3.2
Currently, I'm wondering whether above piece of code is the source of the problem or something else.
Thanks,
Hendra Jaya