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Introduce and use Cluster.withLock to achieve cluster-wide locking (#…
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…869)

JAVA-4471
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@stIncMale
stIncMale authored Feb 7, 2022
1 parent 8854c2c commit 47c99b5
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Showing 15 changed files with 126 additions and 88 deletions.
25 changes: 12 additions & 13 deletions driver-core/src/main/com/mongodb/internal/connection/AbstractMultiServerCluster.java
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Original file line number Diff line number Diff line change
Expand Up @@ -89,17 +89,16 @@ MongoException getSrvResolutionException() {

protected void initialize(final Collection<ServerAddress> serverAddresses) {
ClusterDescription currentDescription = getCurrentDescription();
ClusterDescription newDescription;

// synchronizing this code because addServer registers a callback which is re-entrant to this instance.
// In other words, we are leaking a reference to "this" from the constructor.
synchronized (this) {
withLock(() -> {
for (final ServerAddress serverAddress : serverAddresses) {
addServer(serverAddress);
}
newDescription = updateDescription();
ClusterDescription newDescription = updateDescription();
fireChangeEvent(newDescription, currentDescription);
}
});
}

@Override
Expand All @@ -111,14 +110,14 @@ protected void connect() {

@Override
public void close() {
synchronized (this) {
withLock(() -> {
if (!isClosed()) {
for (final ServerTuple serverTuple : addressToServerTupleMap.values()) {
serverTuple.server.close();
}
}
super.close();
}
});
}

@Override
Expand All @@ -141,7 +140,7 @@ public void serverDescriptionChanged(final ServerDescriptionChangedEvent event)
}

void onChange(final Collection<ServerAddress> newHosts) {
synchronized (this) {
withLock(() -> {
if (isClosed()) {
return;
}
Expand All @@ -165,14 +164,11 @@ void onChange(final Collection<ServerAddress> newHosts) {
ClusterDescription newClusterDescription = updateDescription();

fireChangeEvent(newClusterDescription, oldClusterDescription);
}
});
}

private void onChange(final ServerDescriptionChangedEvent event) {
ClusterDescription oldClusterDescription = null;
ClusterDescription newClusterDescription = null;
boolean shouldUpdateDescription = true;
synchronized (this) {
withLock(() -> {
if (isClosed()) {
return;
}
Expand All @@ -193,6 +189,7 @@ private void onChange(final ServerDescriptionChangedEvent event) {
return;
}

boolean shouldUpdateDescription = true;
if (newDescription.isOk()) {
if (clusterType == UNKNOWN && newDescription.getType() != REPLICA_SET_GHOST) {
clusterType = newDescription.getClusterType();
Expand All @@ -216,6 +213,8 @@ private void onChange(final ServerDescriptionChangedEvent event) {
}
}

ClusterDescription oldClusterDescription = null;
ClusterDescription newClusterDescription = null;
if (shouldUpdateDescription) {
serverTuple.description = newDescription;
oldClusterDescription = getCurrentDescription();
Expand All @@ -224,7 +223,7 @@ private void onChange(final ServerDescriptionChangedEvent event) {
if (shouldUpdateDescription) {
fireChangeEvent(newClusterDescription, oldClusterDescription);
}
}
});
}

private boolean handleReplicaSetMemberChanged(final ServerDescription newDescription) {
Expand Down
61 changes: 36 additions & 25 deletions driver-core/src/main/com/mongodb/internal/connection/BaseCluster.java
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Original file line number Diff line number Diff line change
Expand Up @@ -240,13 +240,15 @@ public boolean isClosed() {
return isClosed;
}

protected synchronized void updateDescription(final ClusterDescription newDescription) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug(format("Updating cluster description to %s", newDescription.getShortDescription()));
}
protected void updateDescription(final ClusterDescription newDescription) {
withLock(() -> {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug(format("Updating cluster description to %s", newDescription.getShortDescription()));
}

description = newDescription;
updatePhase();
description = newDescription;
updatePhase();
});
}

/**
Expand All @@ -265,8 +267,13 @@ public ClusterDescription getCurrentDescription() {
return description;
}

private synchronized void updatePhase() {
phase.getAndSet(new CountDownLatch(1)).countDown();
@Override
public synchronized void withLock(final Runnable action) {
action.run();
}

private void updatePhase() {
withLock(() -> phase.getAndSet(new CountDownLatch(1)).countDown());
}

private long getMaxWaitTimeNanos() {
Expand Down Expand Up @@ -387,7 +394,7 @@ private ServerSelector getCompositeServerSelector(final ServerSelector serverSel

protected ClusterableServer createServer(final ServerAddress serverAddress,
final ServerDescriptionChangedListener serverDescriptionChangedListener) {
return serverFactory.create(serverAddress, serverDescriptionChangedListener, clusterClock);
return serverFactory.create(this, serverAddress, serverDescriptionChangedListener, clusterClock);
}

private void throwIfIncompatible(final ClusterDescription curDescription) {
Expand Down Expand Up @@ -456,26 +463,30 @@ long getRemainingTime() {
}
}

private synchronized void notifyWaitQueueHandler(final ServerSelectionRequest request) {
if (isClosed) {
return;
}
private void notifyWaitQueueHandler(final ServerSelectionRequest request) {
withLock(() -> {
if (isClosed) {
return;
}

waitQueue.add(request);
waitQueue.add(request);

if (waitQueueHandler == null) {
waitQueueHandler = new Thread(new WaitQueueHandler(), "cluster-" + clusterId.getValue());
waitQueueHandler.setDaemon(true);
waitQueueHandler.start();
} else {
updatePhase();
}
if (waitQueueHandler == null) {
waitQueueHandler = new Thread(new WaitQueueHandler(), "cluster-" + clusterId.getValue());
waitQueueHandler.setDaemon(true);
waitQueueHandler.start();
} else {
updatePhase();
}
});
}

private synchronized void stopWaitQueueHandler() {
if (waitQueueHandler != null) {
waitQueueHandler.interrupt();
}
private void stopWaitQueueHandler() {
withLock(() -> {
if (waitQueueHandler != null) {
waitQueueHandler.interrupt();
}
});
}

private final class WaitQueueHandler implements Runnable {
Expand Down
7 changes: 7 additions & 0 deletions driver-core/src/main/com/mongodb/internal/connection/Cluster.java
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Original file line number Diff line number Diff line change
Expand Up @@ -92,4 +92,11 @@ public interface Cluster extends Closeable {
* @return true if all the servers in this cluster have been closed
*/
boolean isClosed();

/**
* Does the supplied {@code action} while holding a reentrant cluster-wide lock.
*
* @param action The action to {@linkplain Runnable#run() do}.
*/
void withLock(Runnable action);
}
4 changes: 2 additions & 2 deletions driver-core/src/main/com/mongodb/internal/connection/ClusterableServerFactory.java
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Original file line number Diff line number Diff line change
Expand Up @@ -20,8 +20,8 @@
import com.mongodb.connection.ServerSettings;

public interface ClusterableServerFactory {
ClusterableServer create(ServerAddress serverAddress, ServerDescriptionChangedListener serverDescriptionChangedListener,
ClusterClock clusterClock);
ClusterableServer create(Cluster cluster, ServerAddress serverAddress,
ServerDescriptionChangedListener serverDescriptionChangedListener, ClusterClock clusterClock);

ServerSettings getSettings();
}
4 changes: 2 additions & 2 deletions driver-core/src/main/com/mongodb/internal/connection/DefaultClusterableServerFactory.java
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Original file line number Diff line number Diff line change
Expand Up @@ -76,7 +76,7 @@ public DefaultClusterableServerFactory(final ClusterId clusterId, final ClusterS
}

@Override
public ClusterableServer create(final ServerAddress serverAddress,
public ClusterableServer create(final Cluster cluster, final ServerAddress serverAddress,
final ServerDescriptionChangedListener serverDescriptionChangedListener,
final ClusterClock clusterClock) {
ServerId serverId = new ServerId(clusterId, serverAddress);
Expand All @@ -91,7 +91,7 @@ mongoDriverInformation, emptyList(), null, serverApi),
mongoDriverInformation, compressorList, commandListener, serverApi),
connectionPoolSettings, internalConnectionPoolSettings, sdamProvider);
ServerListener serverListener = singleServerListener(serverSettings);
SdamServerDescriptionManager sdam = new DefaultSdamServerDescriptionManager(serverId, serverDescriptionChangedListener,
SdamServerDescriptionManager sdam = new DefaultSdamServerDescriptionManager(cluster, serverId, serverDescriptionChangedListener,
serverListener, serverMonitor, connectionPool, clusterSettings.getMode());
sdamProvider.initialize(sdam);
serverMonitor.start();
Expand Down
31 changes: 8 additions & 23 deletions ...er-core/src/main/com/mongodb/internal/connection/DefaultSdamServerDescriptionManager.java
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Original file line number Diff line number Diff line change
Expand Up @@ -24,9 +24,6 @@
import com.mongodb.event.ServerDescriptionChangedEvent;
import com.mongodb.event.ServerListener;

import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

import static com.mongodb.assertions.Assertions.assertFalse;
import static com.mongodb.assertions.Assertions.assertNotNull;
import static com.mongodb.assertions.Assertions.assertTrue;
Expand All @@ -36,34 +33,34 @@

@ThreadSafe
final class DefaultSdamServerDescriptionManager implements SdamServerDescriptionManager {
private final Cluster cluster;
private final ServerId serverId;
private final ServerDescriptionChangedListener serverDescriptionChangedListener;
private final ServerListener serverListener;
private final ServerMonitor serverMonitor;
private final ConnectionPool connectionPool;
private final ClusterConnectionMode connectionMode;
private final Lock lock;
private volatile ServerDescription description;

DefaultSdamServerDescriptionManager(final ServerId serverId,
DefaultSdamServerDescriptionManager(final Cluster cluster,
final ServerId serverId,
final ServerDescriptionChangedListener serverDescriptionChangedListener,
final ServerListener serverListener, final ServerMonitor serverMonitor,
final ConnectionPool connectionPool,
final ClusterConnectionMode connectionMode) {
this.cluster = cluster;
this.serverId = assertNotNull(serverId);
this.serverDescriptionChangedListener = assertNotNull(serverDescriptionChangedListener);
this.serverListener = assertNotNull(serverListener);
this.serverMonitor = assertNotNull(serverMonitor);
this.connectionPool = assertNotNull(connectionPool);
this.connectionMode = assertNotNull(connectionMode);
description = unknownConnectingServerDescription(serverId, null);
lock = new ReentrantLock();
}

@Override
public void update(final ServerDescription candidateDescription) {
lock.lock();
try {
cluster.withLock(() -> {
if (TopologyVersionHelper.newer(description.getTopologyVersion(), candidateDescription.getTopologyVersion())) {
return;
}
Expand All @@ -85,29 +82,17 @@ public void update(final ServerDescription candidateDescription) {
assertFalse(markedPoolReady);
connectionPool.invalidate(candidateDescriptionException);
}
} finally {
lock.unlock();
}
});
}

@Override
public void handleExceptionBeforeHandshake(final SdamIssue sdamIssue) {
lock.lock();
try {
handleException(sdamIssue, true);
} finally {
lock.unlock();
}
cluster.withLock(() -> handleException(sdamIssue, true));
}

@Override
public void handleExceptionAfterHandshake(final SdamIssue sdamIssue) {
lock.lock();
try {
handleException(sdamIssue, false);
} finally {
lock.unlock();
}
cluster.withLock(() -> handleException(sdamIssue, false));
}

@Override
Expand Down
7 changes: 6 additions & 1 deletion driver-core/src/main/com/mongodb/internal/connection/LoadBalancedCluster.java
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Original file line number Diff line number Diff line change
Expand Up @@ -159,7 +159,7 @@ private void init(final ClusterId clusterId, final ClusterableServerFactory serv
.address(host)
.build()),
settings, serverFactory.getSettings());
server = serverFactory.create(host, event -> { }, clusterClock);
server = serverFactory.create(this, host, event -> { }, clusterClock);

clusterListener.clusterDescriptionChanged(new ClusterDescriptionChangedEvent(clusterId, description, initialDescription));
}
Expand Down Expand Up @@ -282,6 +282,11 @@ public boolean isClosed() {
return closed.get();
}

@Override
public void withLock(final Runnable action) {
fail();
}

private void handleServerSelectionRequest(final ServerSelectionRequest serverSelectionRequest) {
assertTrue(initializationCompleted);
if (srvRecordResolvedToMultipleHosts) {
Expand Down
2 changes: 1 addition & 1 deletion ...r-core/src/main/com/mongodb/internal/connection/LoadBalancedClusterableServerFactory.java
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Original file line number Diff line number Diff line change
Expand Up @@ -70,7 +70,7 @@ public LoadBalancedClusterableServerFactory(final ClusterId clusterId, final Ser
}

@Override
public ClusterableServer create(final ServerAddress serverAddress,
public ClusterableServer create(final Cluster cluster, final ServerAddress serverAddress,
final ServerDescriptionChangedListener serverDescriptionChangedListener,
final ClusterClock clusterClock) {
ConnectionPool connectionPool = new DefaultConnectionPool(new ServerId(clusterId, serverAddress),
Expand Down
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