vmlens shows you all detected deadlocks in the Race Conditions, Deadlocks View. To analyze a deadlock expand it, to see the stack traces of the two threads:
In the example above Thread On Start/Stop tries to acquire Monitor@AbstractFileSystem after acquiring Monitor@AbstractFolder. Thread Inactive RequestProcessor tries to acquire the two monitors in reverse order leading to potential deadlock.
We can fix the deadlock by using tryLock of java.util.concurrent.locks.ReentrantLock instead of monitors.