org.opendaylight.mdsal.dom.broker.pingpong

Class PingPongTransactionChain

java.lang.Object

org.opendaylight.mdsal.dom.broker.pingpong.PingPongTransactionChain

All Implemented Interfaces:

AutoCloseable, DOMTransactionChain, DOMTransactionFactory, org.opendaylight.yangtools.concepts.Registration

public final class PingPongTransactionChain
extends Object
implements DOMTransactionChain

An implementation of DOMTransactionChain, which has a very specific behavior, which some users may find surprising. If keeps the general intent of the contract, but it makes sure there are never more than two transactions allocated at any given time: one of them is being committed, and while that is happening, the other one acts as a scratch pad. Once the committing transaction completes successfully, the scratch transaction is enqueued as soon as it is ready.

This mode of operation means that there is no inherent isolation between the front-end transactions and transactions cannot be reasonably cancelled.

It furthermore means that the transactions returned by newReadOnlyTransaction() counts as an outstanding transaction and the user may not allocate multiple read-only transactions at the same time.

Method Summary

Modifier and Type	Method and Description
void	close()
DOMDataTreeReadTransaction	newReadOnlyTransaction() Create a new read only transaction which will continue the chain.
DOMDataTreeReadWriteTransaction	newReadWriteTransaction() Create a new read-write transaction which will continue the chain.
DOMDataTreeWriteTransaction	newWriteOnlyTransaction() Create a new write-only transaction which will continue the chain.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface org.opendaylight.yangtools.concepts.Registration

newReadOnlyTransaction

public DOMDataTreeReadTransaction newReadOnlyTransaction()

Description copied from interface: DOMTransactionChain

Create a new read only transaction which will continue the chain.

The previous write transaction has to be either SUBMITTED (commit was invoked) or CANCELLED (close was invoked).

The returned read-only transaction presents an isolated view of the data if the previous write transaction was successful - in other words, this read-only transaction will see the state changes made by the previous write transaction in the chain. However, state which was introduced by other transactions outside this transaction chain after creation of the previous transaction is not visible.

Specified by:

newReadOnlyTransaction in interface DOMTransactionChain

Specified by:

newReadOnlyTransaction in interface DOMTransactionFactory

Returns:

New transaction in the chain.

newReadWriteTransaction

public DOMDataTreeReadWriteTransaction newReadWriteTransaction()

Description copied from interface: DOMTransactionChain

Create a new read-write transaction which will continue the chain.

The previous write transaction has to be either SUBMITTED (commit was invoked) or CANCELLED (close was invoked).

The returned read-write transaction presents an isolated view of the data if the previous write transaction was successful - in other words, this read-write transaction will see the state changes made by the previous write transaction in the chain. However, state which was introduced by other transactions outside this transaction chain after creation of the previous transaction is not visible.

Committing this read-write transaction using commit will commit the state changes in this transaction to be visible to any subsequent transaction in this chain and also to any transaction outside this chain.

Specified by:

newReadWriteTransaction in interface DOMTransactionChain

Specified by:

newReadWriteTransaction in interface DOMTransactionFactory

Returns:

New transaction in the chain.

newWriteOnlyTransaction

public DOMDataTreeWriteTransaction newWriteOnlyTransaction()

Description copied from interface: DOMTransactionChain

Create a new write-only transaction which will continue the chain.

The previous write transaction has to be either SUBMITTED (commit was invoked) or CANCELLED (close was invoked)

The returned write-only transaction presents an isolated view of the data if the previous write transaction was successful - in other words, this write-only transaction will see the state changes made by the previous write transaction in the chain. However, state which was introduced by other transactions outside this transaction chain after creation of the previous transaction is not visible

Committing this write-only transaction using commit will commit the state changes in this transaction to be visible to any subsequent transaction in this chain and also to any transaction outside this chain.

Specified by:

newWriteOnlyTransaction in interface DOMTransactionChain

Specified by:

newWriteOnlyTransaction in interface DOMTransactionFactory

Returns:

New transaction in the chain.