This is the document describing the incremental optimistic locking Dan and myself discussed last week: http://community.jboss.org/wiki/IncrementalOptimisticLocking

Unless I'm missing something, this together with lock reordering[1] cover 100% of the possible deadlock situations in the optimistic locking scheme[2] - which is pretty awesome!

Cheers,

Mircea   

[1] http://community.jboss.org/wiki/LockReorderingForAvoidingDeadlocks

[2] http://community.jboss.org/wiki/OptimisticLockingInInfinispan