2 * Copyright (c) 2016 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.controller.cluster.databroker.actors.dds;
10 import com.google.common.base.Preconditions;
11 import com.google.common.base.Verify;
12 import java.util.Collection;
13 import java.util.HashMap;
15 import java.util.concurrent.ConcurrentHashMap;
16 import java.util.concurrent.atomic.AtomicLongFieldUpdater;
17 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
18 import java.util.concurrent.locks.StampedLock;
19 import javax.annotation.concurrent.GuardedBy;
20 import org.opendaylight.controller.cluster.access.client.AbstractClientConnection;
21 import org.opendaylight.controller.cluster.access.client.ConnectedClientConnection;
22 import org.opendaylight.controller.cluster.access.client.ConnectionEntry;
23 import org.opendaylight.controller.cluster.access.client.InversibleLockException;
24 import org.opendaylight.controller.cluster.access.commands.CreateLocalHistoryRequest;
25 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
26 import org.opendaylight.controller.cluster.access.concepts.Response;
27 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
28 import org.opendaylight.mdsal.common.api.TransactionChainClosedException;
29 import org.opendaylight.yangtools.concepts.Identifiable;
30 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
31 import org.slf4j.Logger;
32 import org.slf4j.LoggerFactory;
35 * Abstract base class for client view of a history. This class has two implementations, one for normal local histories
36 * and the other for single transactions.
38 * @author Robert Varga
40 public abstract class AbstractClientHistory extends LocalAbortable implements Identifiable<LocalHistoryIdentifier> {
47 private static final Logger LOG = LoggerFactory.getLogger(AbstractClientHistory.class);
48 private static final AtomicLongFieldUpdater<AbstractClientHistory> NEXT_TX_UPDATER =
49 AtomicLongFieldUpdater.newUpdater(AbstractClientHistory.class, "nextTx");
50 private static final AtomicReferenceFieldUpdater<AbstractClientHistory, State> STATE_UPDATER =
51 AtomicReferenceFieldUpdater.newUpdater(AbstractClientHistory.class, State.class, "state");
54 private final Map<TransactionIdentifier, AbstractClientHandle<?>> openTransactions = new HashMap<>();
56 private final Map<TransactionIdentifier, AbstractTransactionCommitCohort> readyTransactions = new HashMap<>();
59 private final Map<Long, ProxyHistory> histories = new ConcurrentHashMap<>();
60 private final StampedLock lock = new StampedLock();
62 private final AbstractDataStoreClientBehavior client;
63 private final LocalHistoryIdentifier identifier;
65 // Used via NEXT_TX_UPDATER
66 @SuppressWarnings("unused")
67 private volatile long nextTx = 0;
69 private volatile State state = State.IDLE;
71 AbstractClientHistory(final AbstractDataStoreClientBehavior client, final LocalHistoryIdentifier identifier) {
72 this.client = Preconditions.checkNotNull(client);
73 this.identifier = Preconditions.checkNotNull(identifier);
74 Preconditions.checkArgument(identifier.getCookie() == 0);
81 final void updateState(final State expected, final State next) {
82 final boolean success = STATE_UPDATER.compareAndSet(this, expected, next);
83 Preconditions.checkState(success, "Race condition detected, state changed from %s to %s", expected, state);
84 LOG.debug("Client history {} changed state from {} to {}", this, expected, next);
87 final synchronized void doClose() {
88 final State local = state;
89 if (local != State.CLOSED) {
90 Preconditions.checkState(local == State.IDLE, "Local history %s has an open transaction", this);
91 histories.values().forEach(ProxyHistory::close);
92 updateState(local, State.CLOSED);
96 final synchronized void onProxyDestroyed(final ProxyHistory proxyHistory) {
97 histories.remove(proxyHistory.getIdentifier().getCookie());
98 LOG.debug("{}: removed destroyed proxy {}", this, proxyHistory);
102 public LocalHistoryIdentifier getIdentifier() {
106 final long nextTx() {
107 return NEXT_TX_UPDATER.getAndIncrement(this);
110 final Long resolveShardForPath(final YangInstanceIdentifier path) {
111 return client.resolveShardForPath(path);
115 final void localAbort(final Throwable cause) {
116 final State oldState = STATE_UPDATER.getAndSet(this, State.CLOSED);
117 if (oldState != State.CLOSED) {
118 LOG.debug("Force-closing history {}", getIdentifier(), cause);
120 synchronized (this) {
121 for (AbstractClientHandle<?> t : openTransactions.values()) {
124 openTransactions.clear();
125 readyTransactions.clear();
131 * Create a new history proxy for a given shard.
133 * @throws InversibleLockException if the shard is being reconnected
136 private ProxyHistory createHistoryProxy(final Long shard) {
137 final AbstractClientConnection<ShardBackendInfo> connection = client.getConnection(shard);
138 final LocalHistoryIdentifier proxyId = new LocalHistoryIdentifier(identifier.getClientId(),
139 identifier.getHistoryId(), shard);
140 LOG.debug("Created proxyId {} for history {} shard {}", proxyId, identifier, shard);
142 final ProxyHistory ret = createHistoryProxy(proxyId, connection);
144 // Request creation of the history, if it is not the single history
145 if (ret.getIdentifier().getHistoryId() != 0) {
146 connection.sendRequest(new CreateLocalHistoryRequest(ret.getIdentifier(), connection.localActor()),
147 this::createHistoryCallback);
152 abstract ProxyHistory createHistoryProxy(LocalHistoryIdentifier historyId,
153 AbstractClientConnection<ShardBackendInfo> connection);
155 private void createHistoryCallback(final Response<?, ?> response) {
156 LOG.debug("Create history response {}", response);
159 private ProxyHistory ensureHistoryProxy(final TransactionIdentifier transactionId, final Long shard) {
162 // Short-lived lock to ensure exclusion of createHistoryProxy and the lookup phase in startReconnect,
163 // see comments in startReconnect() for details.
164 final long stamp = lock.readLock();
166 return histories.computeIfAbsent(shard, this::createHistoryProxy);
168 lock.unlockRead(stamp);
170 } catch (InversibleLockException e) {
171 LOG.trace("Waiting for transaction {} shard {} connection to resolve", transactionId, shard);
173 LOG.trace("Retrying transaction {} shard {} connection", transactionId, shard);
178 final AbstractProxyTransaction createSnapshotProxy(final TransactionIdentifier transactionId, final Long shard) {
179 return ensureHistoryProxy(transactionId, shard).createTransactionProxy(transactionId, true);
182 final AbstractProxyTransaction createTransactionProxy(final TransactionIdentifier transactionId, final Long shard) {
183 return ensureHistoryProxy(transactionId, shard).createTransactionProxy(transactionId, false);
186 private void checkNotClosed() {
187 if (state == State.CLOSED) {
188 throw new TransactionChainClosedException(String.format("Local history %s is closed", identifier));
193 * Allocate a new {@link ClientTransaction}.
195 * @return A new {@link ClientTransaction}
196 * @throws TransactionChainClosedException if this history is closed
197 * @throws IllegalStateException if a previous dependent transaction has not been closed
199 public ClientTransaction createTransaction() {
202 synchronized (this) {
203 final ClientTransaction ret = doCreateTransaction();
204 openTransactions.put(ret.getIdentifier(), ret);
210 * Create a new {@link ClientSnapshot}.
212 * @return A new {@link ClientSnapshot}
213 * @throws TransactionChainClosedException if this history is closed
214 * @throws IllegalStateException if a previous dependent transaction has not been closed
216 public ClientSnapshot takeSnapshot() {
219 synchronized (this) {
220 final ClientSnapshot ret = doCreateSnapshot();
221 openTransactions.put(ret.getIdentifier(), ret);
227 abstract ClientSnapshot doCreateSnapshot();
230 abstract ClientTransaction doCreateTransaction();
233 * Callback invoked from {@link ClientTransaction} when a child transaction readied for submission.
235 * @param txId Transaction identifier
236 * @param cohort Transaction commit cohort
238 synchronized AbstractTransactionCommitCohort onTransactionReady(final ClientTransaction tx,
239 final AbstractTransactionCommitCohort cohort) {
240 final TransactionIdentifier txId = tx.getIdentifier();
241 if (openTransactions.remove(txId) == null) {
242 LOG.warn("Transaction {} not recorded, proceeding with readiness", txId);
245 final AbstractTransactionCommitCohort previous = readyTransactions.putIfAbsent(txId, cohort);
246 Preconditions.checkState(previous == null, "Duplicate cohort %s for transaction %s, already have %s",
247 cohort, txId, previous);
249 LOG.debug("Local history {} readied transaction {}", this, txId);
254 * Callback invoked from {@link ClientTransaction} when a child transaction has been aborted without touching
257 * @param snapshot transaction identifier
259 synchronized void onTransactionAbort(final AbstractClientHandle<?> snapshot) {
260 if (openTransactions.remove(snapshot.getIdentifier()) == null) {
261 LOG.warn("Could not find aborting transaction {}", snapshot.getIdentifier());
266 * Callback invoked from {@link AbstractTransactionCommitCohort} when a child transaction has been completed
267 * and all its state can be removed.
269 * @param txId transaction identifier
271 synchronized void onTransactionComplete(final TransactionIdentifier txId) {
272 if (readyTransactions.remove(txId) == null) {
273 LOG.warn("Could not find completed transaction {}", txId);
277 HistoryReconnectCohort startReconnect(final ConnectedClientConnection<ShardBackendInfo> newConn) {
279 * This looks ugly and unusual and there is a reason for that, as the locking involved is in multiple places.
281 * We need to make sure that a new proxy is not created while we are reconnecting, which is partially satisfied
282 * by client.getConnection() throwing InversibleLockException by the time this method is invoked. That does
283 * not cover the case when createHistoryProxy() has already acquired the connection, but has not yet populated
286 * Hence we need to make sure no potential computation is happening concurrently with us looking at the history
287 * map. Once we have performed that lookup, though, we can release the lock immediately, as all creation
288 * requests are established to happen either before or after the reconnect attempt.
290 final ProxyHistory oldProxy;
291 final long stamp = lock.writeLock();
293 oldProxy = histories.get(newConn.cookie());
295 lock.unlockWrite(stamp);
298 if (oldProxy == null) {
302 final ProxyReconnectCohort proxy = Verify.verifyNotNull(oldProxy.startReconnect(newConn));
303 return new HistoryReconnectCohort() {
305 ProxyReconnectCohort getProxy() {
310 void replayRequests(final Collection<ConnectionEntry> previousEntries) {
311 proxy.replayRequests(previousEntries);
315 public void close() {
316 LOG.debug("Client history {} finishing reconnect to {}", AbstractClientHistory.this, newConn);
317 final ProxyHistory newProxy = proxy.finishReconnect();
318 if (!histories.replace(newConn.cookie(), oldProxy, newProxy)) {
319 LOG.warn("Failed to replace proxy {} with {} in {}", oldProxy, newProxy,
320 AbstractClientHistory.this);