org.apache.pulsar.metadata.coordination.impl.LockManagerImpl Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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* http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.pulsar.metadata.coordination.impl;
import com.fasterxml.jackson.databind.type.TypeFactory;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ScheduledExecutorService;
import java.util.stream.Collectors;
import lombok.extern.slf4j.Slf4j;
import org.apache.pulsar.common.util.FutureUtil;
import org.apache.pulsar.metadata.api.MetadataCache;
import org.apache.pulsar.metadata.api.MetadataSerde;
import org.apache.pulsar.metadata.api.MetadataStoreException;
import org.apache.pulsar.metadata.api.MetadataStoreException.BadVersionException;
import org.apache.pulsar.metadata.api.MetadataStoreException.LockBusyException;
import org.apache.pulsar.metadata.api.Notification;
import org.apache.pulsar.metadata.api.NotificationType;
import org.apache.pulsar.metadata.api.coordination.LockManager;
import org.apache.pulsar.metadata.api.coordination.ResourceLock;
import org.apache.pulsar.metadata.api.extended.MetadataStoreExtended;
import org.apache.pulsar.metadata.api.extended.SessionEvent;
import org.apache.pulsar.metadata.cache.impl.JSONMetadataSerdeSimpleType;
@Slf4j
class LockManagerImpl implements LockManager {
private final Map> locks = new ConcurrentHashMap<>();
private final MetadataStoreExtended store;
private final MetadataCache cache;
private final MetadataSerde serde;
private final FutureUtil.Sequencer sequencer;
private final ScheduledExecutorService executor;
private enum State {
Ready, Closed
}
private State state = State.Ready;
LockManagerImpl(MetadataStoreExtended store, Class clazz, ScheduledExecutorService executor) {
this(store, new JSONMetadataSerdeSimpleType<>(
TypeFactory.defaultInstance().constructSimpleType(clazz, null)),
executor);
}
LockManagerImpl(MetadataStoreExtended store, MetadataSerde serde, ScheduledExecutorService executor) {
this.store = store;
this.cache = store.getMetadataCache(serde);
this.serde = serde;
this.executor = executor;
this.sequencer = FutureUtil.Sequencer.create();
store.registerSessionListener(this::handleSessionEvent);
store.registerListener(this::handleDataNotification);
}
@Override
public CompletableFuture> readLock(String path) {
return cache.get(path);
}
@Override
public CompletableFuture> acquireLock(String path, T value) {
ResourceLockImpl lock = new ResourceLockImpl<>(store, serde, path, executor);
CompletableFuture> result = new CompletableFuture<>();
lock.acquire(value).thenRun(() -> {
synchronized (LockManagerImpl.this) {
if (state == State.Ready) {
locks.put(path, lock);
lock.getLockExpiredFuture().thenRun(() -> {
log.info("Released resource lock on {}", path);
synchronized (LockManagerImpl.this) {
locks.remove(path, lock);
}
});
} else {
// LockManager was closed in between. Release the lock asynchronously
lock.release();
}
}
result.complete(lock);
}).exceptionally(ex -> {
if (ex.getCause() instanceof BadVersionException) {
result.completeExceptionally(
new LockBusyException("Resource at " + path + " is already locked"));
} else {
result.completeExceptionally(ex.getCause());
}
return null;
});
return result;
}
private void handleSessionEvent(SessionEvent se) {
// We want to make sure we're processing one event at a time and that we're done with one event before going
// for the next one.
sequencer.sequential(() -> FutureUtil.composeAsync(() -> {
final List> futures = new ArrayList<>();
if (se == SessionEvent.SessionReestablished) {
log.info("Metadata store session has been re-established. Revalidating all the existing locks.");
for (ResourceLockImpl lock : locks.values()) {
futures.add(lock.silentRevalidateOnce());
}
} else if (se == SessionEvent.Reconnected) {
log.info("Metadata store connection has been re-established. Revalidating locks that were pending.");
for (ResourceLockImpl lock : locks.values()) {
futures.add(lock.revalidateIfNeededAfterReconnection());
}
}
return FutureUtil.waitForAll(futures)
.exceptionally(ex -> {
log.warn("Failure when processing session event", ex);
return null;
});
}, executor));
}
private void handleDataNotification(Notification n) {
if (n.getType() == NotificationType.Deleted) {
ResourceLockImpl lock = locks.get(n.getPath());
if (lock != null) {
lock.lockWasInvalidated();
}
}
}
@Override
public CompletableFuture> listLocks(String path) {
return cache.getChildren(path);
}
@Override
public void close() throws Exception {
try {
asyncClose().join();
} catch (CompletionException e) {
throw MetadataStoreException.unwrap(e);
}
}
@Override
public CompletableFuture asyncClose() {
Map> locks;
synchronized (this) {
if (state != State.Ready) {
return CompletableFuture.completedFuture(null);
}
locks = new HashMap<>(this.locks);
this.state = State.Closed;
}
return FutureUtil.waitForAll(locks.values().stream()
.map(ResourceLock::release)
.collect(Collectors.toList()));
}
}