2 * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.mdsal.binding.api;
10 import java.util.Collection;
11 import javax.annotation.Nonnull;
14 * A data producer context. It allows transactions to be submitted to the subtrees specified at
15 * instantiation time. At any given time there may be a single transaction open. It needs to be
16 * either submitted or cancelled before another one can be open. Once a transaction is submitted, it
17 * will proceed to be committed asynchronously.
20 * Each instance has an upper bound on the number of transactions which can be in-flight, once that
21 * capacity is exceeded, an attempt to create a new transaction will block until some transactions
25 * Each {@link DataTreeProducer} can be in two logical states, bound and unbound, which define the
26 * lifecycle rules for when is it legal to create and submit transactions in relationship with
27 * {@link DataTreeListener} callbacks.
30 * When a producer is first created, it is unbound. In this state the producer can be accessed by
31 * any application thread to allocate or submit transactions, as long as the 'single open
32 * transaction' rule is maintained. The producer and any transaction object MUST NOT be accessed,
33 * directly or indirectly, from a {@link DataTreeListener} callback.
36 * When a producer is referenced in a call to
37 * {@link DataTreeService#registerListener(DataTreeListener, java.util.Collection, boolean, java.util.Collection)}
38 * , an attempt will be made to bind the producer to the specified {@link DataTreeListener}. Such an
39 * attempt will fail the producer is already bound, or it has an open transaction. Once bound, the
40 * producer can only be accessed from within the {@link DataTreeListener} callback on that
41 * particular instance. Any transaction which is not submitted by the time the callback returns will
42 * be implicitly cancelled. A producer becomes unbound when the listener it is bound to becomes
46 public interface DataTreeProducer extends DataTreeProducerFactory, AutoCloseable {
48 * Allocate a new open transaction on this producer. Any and all transactions previously
49 * allocated must have been either submitted or cancelled by the time this method is invoked.
51 * @param isolated Indicates whether this transaction should be a barrier. A barrier transaction
52 * is processed separately from any preceding transactions. Non-barrier transactions may
53 * be merged and processed in a batch, such that any observers see the modifications
54 * contained in them as if the modifications were made in a single transaction.
55 * @return A new {@link CursorAwareWriteTransaction}
56 * @throws IllegalStateException if a previous transaction was not closed.
57 * @throws IllegalThreadStateException if the calling thread context does not match the
58 * lifecycle rules enforced by the producer state (e.g. bound or unbound). This
59 * exception is thrown on a best effort basis and programs should not rely on it for
63 CursorAwareWriteTransaction createTransaction(boolean isolated);
69 * When invoked on a {@link DataTreeProducer}, this method has additional restrictions. There
70 * may not be an open transaction from this producer. The method needs to be invoked in
71 * appropriate context, e.g. bound or unbound.
74 * Specified subtrees must be accessible by this producer. Accessible means they are a subset of
75 * the subtrees specified when the producer is instantiated. The set is further reduced as child
76 * producers are instantiated -- if you create a producer for /a and then a child for /a/b, /a/b
77 * is not accessible from the first producer.
80 * Once this method returns successfully, this (parent) producer loses the ability to access the
81 * specified paths until the resulting (child) producer is shut down.
83 * @throws IllegalStateException if there is an open transaction
84 * @throws IllegalArgumentException if subtrees contains a subtree which is not accessible by
86 * @throws IllegalThreadStateException if the calling thread context does not match the
87 * lifecycle rules enforced by the producer state (e.g. bound or unbound). This
88 * exception is thrown on a best effort basis and programs should not rely on it for
93 DataTreeProducer createProducer(@Nonnull Collection<DataTreeIdentifier<?>> subtrees);
98 * @throws DataTreeProducerBusyException when there is an open transaction.
101 void close() throws DataTreeProducerException;