9.4.5. Implicit Pessimistic Locking Example

An example of implicit pessimistic locking using a transaction that runs on one of the cache nodes is as follows:

tx.begin()
cache.put(K,V)
cache.put(K2,V2)
cache.put(K,V5)
tx.commit()

When the line cache.put(K,V) executes, a cluster-wide lock is acquired on K.
When the line cache.put(K2,V2) executes, a cluster-wide lock is acquired on K2.
When the line cache.put(K,V5) executes, the lock acquisition is non operational because a cluster-wide lock for K has been previously acquired. The put operation will still occur.
When the line tx.commit() executes, all locks held for this transaction are released.