To prevent a Deadlock from occurring at least one requirement for a deadlock has to be removed...

1 - Mutual exclusion : We can use optimistic locking to prevent mutual exclusion among resources.

2 - Resource holding : A thread has to release all its exclusive locks if it does not succeed in acquiring all exclusive locks for resources required.

3 - No preemption : We can use timeout period for an exclusive lock to get free after a given amount of time.

4 - Circular wait : We can check and ensure that circular wait does not occur, when all exclusive locks have been acquired by all the threads in the same sequence.