import com.google.common.base.MoreObjects;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
-import com.google.common.base.Throwables;
import com.google.common.base.Verify;
import com.google.common.collect.Iterables;
import com.google.common.util.concurrent.CheckedFuture;
import javax.annotation.concurrent.NotThreadSafe;
import org.opendaylight.controller.cluster.access.client.ConnectionEntry;
import org.opendaylight.controller.cluster.access.commands.AbstractLocalTransactionRequest;
+import org.opendaylight.controller.cluster.access.commands.ClosedTransactionException;
import org.opendaylight.controller.cluster.access.commands.IncrementTransactionSequenceRequest;
+import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
import org.opendaylight.controller.cluster.access.commands.TransactionAbortRequest;
import org.opendaylight.controller.cluster.access.commands.TransactionAbortSuccess;
import org.opendaylight.controller.cluster.access.commands.TransactionCanCommitSuccess;
* at which point the request is routed to the successor transaction. This is a relatively heavy-weight solution
* to the problem of state transfer, but the user will observe it only if the race condition is hit.
*/
- private static final class SuccessorState extends State {
+ private static class SuccessorState extends State {
private final CountDownLatch latch = new CountDownLatch(1);
private AbstractProxyTransaction successor;
private State prevState;
+ // SUCCESSOR + DONE
+ private boolean done;
+
SuccessorState() {
super("SUCCESSOR");
}
latch.await();
} catch (InterruptedException e) {
LOG.warn("Interrupted while waiting for latch of {}", successor);
- throw Throwables.propagate(e);
+ throw new RuntimeException(e);
}
return successor;
}
}
State getPrevState() {
- return prevState;
+ return Verify.verifyNotNull(prevState, "Attempted to access previous state, which was not set");
}
void setPrevState(final State prevState) {
Verify.verify(this.prevState == null, "Attempted to set previous state to %s when we already have %s",
prevState, this.prevState);
this.prevState = Preconditions.checkNotNull(prevState);
+ // We cannot have duplicate successor states, so this check is sufficient
+ this.done = DONE.equals(prevState);
}
// To be called from safe contexts, where successor is known to be completed
successor, this.successor);
this.successor = Preconditions.checkNotNull(successor);
}
+
+ boolean isDone() {
+ return done;
+ }
+
+ void setDone() {
+ done = true;
+ }
}
private static final Logger LOG = LoggerFactory.getLogger(AbstractProxyTransaction.class);
* variable. It uses pre-allocated objects for fast paths (i.e. no successor present) and a per-transition object
* for slow paths (when successor is injected/present).
*/
- private volatile int sealed = 0;
- private volatile State state = OPEN;
+ private volatile int sealed;
+ private volatile State state;
- AbstractProxyTransaction(final ProxyHistory parent) {
+ AbstractProxyTransaction(final ProxyHistory parent, final boolean isDone) {
this.parent = Preconditions.checkNotNull(parent);
+ if (isDone) {
+ state = DONE;
+ // DONE implies previous seal operation completed
+ sealed = 1;
+ } else {
+ state = OPEN;
+ }
}
final void executeInActor(final Runnable command) {
}
/**
- * Seal this transaction before it is either committed or aborted.
+ * Seal this transaction before it is either committed or aborted. This method should only be invoked from
+ * application thread.
*/
final void seal() {
// Transition user-visible state first
- final boolean success = SEALED_UPDATER.compareAndSet(this, 0, 1);
+ final boolean success = markSealed();
Preconditions.checkState(success, "Proxy %s was already sealed", getIdentifier());
- internalSeal();
+
+ if (!sealAndSend(Optional.absent())) {
+ sealSuccessor();
+ }
}
- final void ensureSealed() {
- if (SEALED_UPDATER.compareAndSet(this, 0, 1)) {
- internalSeal();
+ /**
+ * Internal seal propagation method, invoked when we have raced with reconnection thread. Note that there may have
+ * been multiple reconnects, so we have to make sure the action is propagate through all intermediate instances.
+ */
+ private void sealSuccessor() {
+ // Slow path: wait for the successor to complete
+ final AbstractProxyTransaction successor = awaitSuccessor();
+
+ // At this point the successor has completed transition and is possibly visible by the user thread, which is
+ // still stuck here. The successor has not seen final part of our state, nor the fact it is sealed.
+ // Propagate state and seal the successor.
+ final java.util.Optional<ModifyTransactionRequest> optState = flushState();
+ if (optState.isPresent()) {
+ forwardToSuccessor(successor, optState.get(), null);
}
+ successor.predecessorSealed();
}
- private void internalSeal() {
- doSeal();
+ private void predecessorSealed() {
+ if (markSealed() && !sealAndSend(Optional.absent())) {
+ sealSuccessor();
+ }
+ }
+
+ void sealOnly() {
parent.onTransactionSealed(this);
+ final boolean success = STATE_UPDATER.compareAndSet(this, OPEN, SEALED);
+ Verify.verify(success, "Attempted to replay seal on %s", this);
+ }
- // Now deal with state transfer, which can occur via successor or a follow-up canCommit() or directCommit().
- if (!STATE_UPDATER.compareAndSet(this, OPEN, SEALED)) {
- // Slow path: wait for the successor to complete
- final AbstractProxyTransaction successor = awaitSuccessor();
+ /**
+ * Seal this transaction and potentially send it out towards the backend. If this method reports false, the caller
+ * needs to deal with propagating the seal operation towards the successor.
+ *
+ * @param enqueuedTicks Enqueue ticks when this is invoked from replay path.
+ * @return True if seal operation was successful, false if this proxy has a successor.
+ */
+ boolean sealAndSend(final Optional<Long> enqueuedTicks) {
+ parent.onTransactionSealed(this);
- // At this point the successor has completed transition and is possibly visible by the user thread, which is
- // still stuck here. The successor has not seen final part of our state, nor the fact it is sealed.
- // Propagate state and seal the successor.
- flushState(successor);
- successor.ensureSealed();
- }
+ // Transition internal state to sealed and detect presence of a successor
+ return STATE_UPDATER.compareAndSet(this, OPEN, SEALED);
+ }
+
+ /**
+ * Mark this proxy as having been sealed.
+ *
+ * @return True if this call has transitioned to sealed state.
+ */
+ final boolean markSealed() {
+ return SEALED_UPDATER.compareAndSet(this, 0, 1);
}
private void checkNotSealed() {
if (t instanceof TransactionCommitSuccess) {
ret.set(Boolean.TRUE);
} else if (t instanceof RequestFailure) {
- ret.setException(((RequestFailure<?, ?>) t).getCause().unwrap());
+ final Throwable cause = ((RequestFailure<?, ?>) t).getCause().unwrap();
+ if (cause instanceof ClosedTransactionException) {
+ // This is okay, as it indicates the transaction has been completed. It can happen
+ // when we lose connectivity with the backend after it has received the request.
+ ret.set(Boolean.TRUE);
+ } else {
+ ret.setException(cause);
+ }
} else {
ret.setException(new IllegalStateException("Unhandled response " + t.getClass()));
}
}
LOG.debug("Transaction {} doCommit completed", this);
+
+ // Needed for ProxyHistory$Local data tree rebase points.
+ parent.completeTransaction(this);
+
enqueuePurge();
});
}
}
final void enqueuePurge(final Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
- enqueueRequest(purgeRequest(), resp -> {
- LOG.debug("Transaction {} purge completed", this);
- parent.completeTransaction(this);
+ LOG.debug("{}: initiating purge", this);
+
+ final State prev = state;
+ if (prev instanceof SuccessorState) {
+ ((SuccessorState) prev).setDone();
+ } else {
+ final boolean success = STATE_UPDATER.compareAndSet(this, prev, DONE);
+ if (!success) {
+ LOG.warn("{}: moved from state {} while we were purging it", this, prev);
+ }
+ }
+
+ successfulRequests.clear();
+
+ enqueueRequest(new TransactionPurgeRequest(getIdentifier(), nextSequence(), localActor()), resp -> {
+ LOG.debug("{}: purge completed", this);
+ parent.purgeTransaction(this);
+
if (callback != null) {
callback.accept(resp);
}
}, enqueuedTicks);
}
- private TransactionPurgeRequest purgeRequest() {
- successfulRequests.clear();
- return new TransactionPurgeRequest(getIdentifier(), nextSequence(), localActor());
- }
-
// Called with the connection unlocked
final synchronized void startReconnect() {
// At this point canCommit/directCommit are blocked, we assert a new successor state, retrieving the previous
final State prevState = local.getPrevState();
final AbstractProxyTransaction successor = successorHistory.createTransactionProxy(getIdentifier(),
- isSnapshotOnly());
- LOG.debug("{} created successor transaction proxy {}", this, successor);
+ isSnapshotOnly(), local.isDone());
+ LOG.debug("{} created successor {}", this, successor);
local.setSuccessor(successor);
// Replay successful requests first
for (Object obj : successfulRequests) {
if (obj instanceof TransactionRequest) {
LOG.debug("Forwarding successful request {} to successor {}", obj, successor);
- successor.replayRequest((TransactionRequest<?>) obj, resp -> { }, now);
+ successor.doReplayRequest((TransactionRequest<?>) obj, resp -> { }, now);
} else {
Verify.verify(obj instanceof IncrementSequence);
final IncrementSequence increment = (IncrementSequence) obj;
- successor.replayRequest(new IncrementTransactionSequenceRequest(getIdentifier(),
+ successor.doReplayRequest(new IncrementTransactionSequenceRequest(getIdentifier(),
increment.getSequence(), localActor(), isSnapshotOnly(), increment.getDelta()), resp -> { },
now);
LOG.debug("Incrementing sequence {} to successor {}", obj, successor);
if (getIdentifier().equals(req.getTarget())) {
Verify.verify(req instanceof TransactionRequest, "Unhandled request %s", req);
LOG.debug("Replaying queued request {} to successor {}", req, successor);
- successor.replayRequest((TransactionRequest<?>) req, e.getCallback(), e.getEnqueuedTicks());
+ successor.doReplayRequest((TransactionRequest<?>) req, e.getCallback(), e.getEnqueuedTicks());
it.remove();
}
}
*/
if (SEALED.equals(prevState)) {
LOG.debug("Proxy {} reconnected while being sealed, propagating state to successor {}", this, successor);
- flushState(successor);
- successor.ensureSealed();
+ final long enqueuedTicks = parent.currentTime();
+ final java.util.Optional<ModifyTransactionRequest> optState = flushState();
+ if (optState.isPresent()) {
+ successor.handleReplayedRemoteRequest(optState.get(), null, enqueuedTicks);
+ }
+ if (successor.markSealed()) {
+ successor.sealAndSend(Optional.of(enqueuedTicks));
+ }
}
}
* @param callback Callback to be invoked once the request completes
* @param enqueuedTicks ticker-based time stamp when the request was enqueued
*/
- private void replayRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback,
+ private void doReplayRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback,
final long enqueuedTicks) {
if (request instanceof AbstractLocalTransactionRequest) {
handleReplayedLocalRequest((AbstractLocalTransactionRequest<?>) request, callback, enqueuedTicks);
}
}
+ final void replayRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback,
+ final long enqueuedTicks) {
+ getSuccessorState().getSuccessor().doReplayRequest(request, callback, enqueuedTicks);
+ }
+
abstract boolean isSnapshotOnly();
abstract void doDelete(YangInstanceIdentifier path);
abstract CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> doRead(YangInstanceIdentifier path);
- abstract void doSeal();
-
@GuardedBy("this")
- abstract void flushState(AbstractProxyTransaction successor);
+ abstract java.util.Optional<ModifyTransactionRequest> flushState();
abstract TransactionRequest<?> abortRequest();
Code Review / controller.git / blobdiff