X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-dom-broker%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fmd%2Fsal%2Fdom%2Fbroker%2Fimpl%2FPingPongTransactionChain.java;h=e72315520f4cdf51f94105ed7f71a4f59aa4de5f;hp=961b6c7b9312948ad862fa5236f7ab66ed834534;hb=2a6aa1775604906755883f810ee9ea6d5f286135;hpb=bfd413d87f82ee3ffed67a141a980805950a0f06
diff --git a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/PingPongTransactionChain.java b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/PingPongTransactionChain.java
index 961b6c7b93..e72315520f 100644
--- a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/PingPongTransactionChain.java
+++ b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/PingPongTransactionChain.java
@@ -7,29 +7,34 @@
*/
package org.opendaylight.controller.md.sal.dom.broker.impl;
+import static com.google.common.base.Preconditions.checkState;
+import static com.google.common.base.Verify.verify;
+import static java.util.Objects.requireNonNull;
+
import com.google.common.base.Optional;
-import com.google.common.base.Preconditions;
import com.google.common.util.concurrent.CheckedFuture;
+import com.google.common.util.concurrent.FluentFuture;
import com.google.common.util.concurrent.FutureCallback;
-import com.google.common.util.concurrent.Futures;
-import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.MoreExecutors;
+import java.util.AbstractMap.SimpleImmutableEntry;
+import java.util.Map.Entry;
+import java.util.concurrent.CancellationException;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
-import javax.annotation.Nonnull;
-import javax.annotation.concurrent.GuardedBy;
-import org.opendaylight.controller.md.sal.common.api.TransactionStatus;
+import org.checkerframework.checker.lock.qual.GuardedBy;
+import org.checkerframework.checker.lock.qual.Holding;
+import org.eclipse.jdt.annotation.NonNull;
import org.opendaylight.controller.md.sal.common.api.data.AsyncTransaction;
import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
import org.opendaylight.controller.md.sal.common.api.data.TransactionChain;
import org.opendaylight.controller.md.sal.common.api.data.TransactionChainListener;
-import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
import org.opendaylight.controller.md.sal.dom.api.DOMDataBroker;
import org.opendaylight.controller.md.sal.dom.api.DOMDataReadOnlyTransaction;
import org.opendaylight.controller.md.sal.dom.api.DOMDataReadWriteTransaction;
import org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction;
import org.opendaylight.controller.md.sal.dom.api.DOMTransactionChain;
import org.opendaylight.controller.md.sal.dom.spi.ForwardingDOMDataReadWriteTransaction;
-import org.opendaylight.yangtools.yang.common.RpcResult;
+import org.opendaylight.mdsal.common.api.CommitInfo;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
import org.slf4j.Logger;
@@ -44,26 +49,35 @@ import org.slf4j.LoggerFactory;
* the committing transaction completes successfully, the scratch transaction
* is enqueued as soon as it is ready.
*
+ *
* This mode of operation means that there is no inherent isolation between
* the front-end transactions and transactions cannot be reasonably cancelled.
*
+ *
* It furthermore means that the transactions returned by {@link #newReadOnlyTransaction()}
* counts as an outstanding transaction and the user may not allocate multiple
* read-only transactions at the same time.
*/
+@Deprecated(forRemoval = true)
public final class PingPongTransactionChain implements DOMTransactionChain {
private static final Logger LOG = LoggerFactory.getLogger(PingPongTransactionChain.class);
+ private final TransactionChainListener listener;
private final DOMTransactionChain delegate;
@GuardedBy("this")
private boolean failed;
+ @GuardedBy("this")
+ private PingPongTransaction shutdownTx;
+ @GuardedBy("this")
+ private Entry deadTx;
/**
* This updater is used to manipulate the "ready" transaction. We perform only atomic
* get-and-set on it.
*/
- private static final AtomicReferenceFieldUpdater READY_UPDATER =
- AtomicReferenceFieldUpdater.newUpdater(PingPongTransactionChain.class, PingPongTransaction.class, "readyTx");
+ private static final AtomicReferenceFieldUpdater READY_UPDATER
+ = AtomicReferenceFieldUpdater
+ .newUpdater(PingPongTransactionChain.class, PingPongTransaction.class, "readyTx");
private volatile PingPongTransaction readyTx;
/**
@@ -72,64 +86,102 @@ public final class PingPongTransactionChain implements DOMTransactionChain {
* us. We perform on compare-and-swap to ensure we properly detect when a user is
* attempting to allocated multiple transactions concurrently.
*/
- private static final AtomicReferenceFieldUpdater LOCKED_UPDATER =
- AtomicReferenceFieldUpdater.newUpdater(PingPongTransactionChain.class, PingPongTransaction.class, "lockedTx");
+ private static final AtomicReferenceFieldUpdater LOCKED_UPDATER
+ = AtomicReferenceFieldUpdater
+ .newUpdater(PingPongTransactionChain.class, PingPongTransaction.class, "lockedTx");
private volatile PingPongTransaction lockedTx;
/**
* This updater is used to manipulate the "inflight" transaction. There can be at most
* one of these at any given time. We perform only compare-and-swap on these.
*/
- private static final AtomicReferenceFieldUpdater INFLIGHT_UPDATER =
- AtomicReferenceFieldUpdater.newUpdater(PingPongTransactionChain.class, PingPongTransaction.class, "inflightTx");
+ private static final AtomicReferenceFieldUpdater INFLIGHT_UPDATER
+ = AtomicReferenceFieldUpdater
+ .newUpdater(PingPongTransactionChain.class, PingPongTransaction.class, "inflightTx");
private volatile PingPongTransaction inflightTx;
PingPongTransactionChain(final DOMDataBroker broker, final TransactionChainListener listener) {
+ this.listener = requireNonNull(listener);
this.delegate = broker.createTransactionChain(new TransactionChainListener() {
@Override
- public void onTransactionChainFailed(final TransactionChain chain, final AsyncTransaction transaction, final Throwable cause) {
- LOG.debug("Delegate chain {} reported failure in {}", chain, transaction, cause);
-
- final DOMDataReadWriteTransaction frontend;
- final PingPongTransaction tx = inflightTx;
- if (tx == null) {
- LOG.warn("Transaction chain {} failed with no pending transactions", chain);
- frontend = null;
- } else {
- frontend = tx.getFrontendTransaction();
- }
-
- listener.onTransactionChainFailed(PingPongTransactionChain.this, frontend, cause);
- delegateFailed();
+ public void onTransactionChainFailed(final TransactionChain chain,
+ final AsyncTransaction transaction, final Throwable cause) {
+ LOG.debug("Transaction chain {} reported failure in {}", chain, transaction, cause);
+ delegateFailed(chain, cause);
}
@Override
public void onTransactionChainSuccessful(final TransactionChain chain) {
- listener.onTransactionChainSuccessful(PingPongTransactionChain.this);
+ delegateSuccessful(chain);
}
});
}
- private synchronized void delegateFailed() {
- failed = true;
+ void delegateSuccessful(final TransactionChain chain) {
+ final Entry canceled;
+ synchronized (this) {
+ // This looks weird, but we need not hold the lock while invoking callbacks
+ canceled = deadTx;
+ }
- /*
- * If we do not have a locked transaction, we need to ensure that
- * the backend transaction is cancelled. Otherwise we can defer
- * until the user calls us.
- */
- if (lockedTx == null) {
- processIfReady();
+ if (canceled == null) {
+ listener.onTransactionChainSuccessful(this);
+ return;
+ }
+
+ // Backend shutdown successful, but we have a batch of transactions we have to report as dead due to the
+ // user calling cancel().
+ final PingPongTransaction tx = canceled.getKey();
+ final Throwable cause = canceled.getValue();
+ LOG.debug("Transaction chain {} successful, failing cancelled transaction {}", chain, tx, cause);
+
+ listener.onTransactionChainFailed(this, tx.getFrontendTransaction(), cause);
+ tx.onFailure(cause);
+ }
+
+ void delegateFailed(final TransactionChain chain, final Throwable cause) {
+
+ final DOMDataReadWriteTransaction frontend;
+ final PingPongTransaction tx = inflightTx;
+ if (tx == null) {
+ LOG.warn("Transaction chain {} failed with no pending transactions", chain);
+ frontend = null;
+ } else {
+ frontend = tx.getFrontendTransaction();
+ }
+
+ listener.onTransactionChainFailed(this, frontend, cause);
+
+ synchronized (this) {
+ failed = true;
+
+ /*
+ * If we do not have a locked transaction, we need to ensure that
+ * the backend transaction is cancelled. Otherwise we can defer
+ * until the user calls us.
+ */
+ if (lockedTx == null) {
+ processIfReady();
+ }
}
}
private synchronized PingPongTransaction slowAllocateTransaction() {
+ checkState(shutdownTx == null, "Transaction chain %s has been shut down", this);
+
+ if (deadTx != null) {
+ throw new IllegalStateException(
+ String.format("Transaction chain %s has failed due to transaction %s being canceled", this,
+ deadTx.getKey()), deadTx.getValue());
+ }
+
final DOMDataReadWriteTransaction delegateTx = delegate.newReadWriteTransaction();
final PingPongTransaction newTx = new PingPongTransaction(delegateTx);
if (!LOCKED_UPDATER.compareAndSet(this, null, newTx)) {
delegateTx.cancel();
- throw new IllegalStateException(String.format("New transaction %s raced with transacion %s", newTx, lockedTx));
+ throw new IllegalStateException(
+ String.format("New transaction %s raced with transaction %s", newTx, lockedTx));
}
return newTx;
@@ -144,13 +196,12 @@ public final class PingPongTransactionChain implements DOMTransactionChain {
return slowAllocateTransaction();
}
- // Fast path: reuse current transaction. We will check
- // failures and similar on submit().
+ // Fast path: reuse current transaction. We will check failures and similar on commit().
if (!LOCKED_UPDATER.compareAndSet(this, null, oldTx)) {
- // Ouch. Delegate chain has not detected a duplicate
- // transaction allocation. This is the best we can do.
+ // Ouch. Delegate chain has not detected a duplicate transaction allocation. This is the best we can do.
oldTx.getTransaction().cancel();
- throw new IllegalStateException(String.format("Reusable transaction %s raced with transaction %s", oldTx, lockedTx));
+ throw new IllegalStateException(
+ String.format("Reusable transaction %s raced with transaction %s", oldTx, lockedTx));
}
return oldTx;
@@ -158,13 +209,16 @@ public final class PingPongTransactionChain implements DOMTransactionChain {
/*
* This forces allocateTransaction() on a slow path, which has to happen after
- * this method has completed executing.
+ * this method has completed executing. Also inflightTx may be updated outside
+ * the lock, hence we need to re-check.
*/
- @GuardedBy("this")
+ @Holding("this")
private void processIfReady() {
- final PingPongTransaction tx = READY_UPDATER.getAndSet(this, null);
- if (tx != null) {
- processTransaction(tx);
+ if (inflightTx == null) {
+ final PingPongTransaction tx = READY_UPDATER.getAndSet(this, null);
+ if (tx != null) {
+ processTransaction(tx);
+ }
}
}
@@ -174,8 +228,8 @@ public final class PingPongTransactionChain implements DOMTransactionChain {
*
* @param tx Transaction which needs processing.
*/
- @GuardedBy("this")
- private void processTransaction(final @Nonnull PingPongTransaction tx) {
+ @Holding("this")
+ private void processTransaction(final @NonNull PingPongTransaction tx) {
if (failed) {
LOG.debug("Cancelling transaction {}", tx);
tx.getTransaction().cancel();
@@ -187,46 +241,72 @@ public final class PingPongTransactionChain implements DOMTransactionChain {
LOG.warn("Submitting transaction {} while {} is still running", tx, inflightTx);
}
- Futures.addCallback(tx.getTransaction().submit(), new FutureCallback() {
+ tx.getTransaction().commit().addCallback(new FutureCallback() {
@Override
- public void onSuccess(final Void result) {
+ public void onSuccess(final CommitInfo result) {
transactionSuccessful(tx, result);
}
@Override
- public void onFailure(final Throwable t) {
- transactionFailed(tx, t);
+ public void onFailure(final Throwable throwable) {
+ transactionFailed(tx, throwable);
}
- });
+ }, MoreExecutors.directExecutor());
}
- private void transactionSuccessful(final PingPongTransaction tx, final Void result) {
- LOG.debug("Transaction {} completed successfully", tx);
-
+ /*
+ * We got invoked from the data store thread. We need to do two things:
+ * 1) release the in-flight transaction
+ * 2) process the potential next transaction
+ *
+ * We have to perform 2) under lock. We could perform 1) without locking, but that means the CAS result may
+ * not be accurate, as a user thread may submit the ready transaction before we acquire the lock -- and checking
+ * for next transaction is not enough, as that may have also be allocated (as a result of a quick
+ * submit/allocate/submit between 1) and 2)). Hence we'd end up doing the following:
+ * 1) CAS of inflightTx
+ * 2) take lock
+ * 3) volatile read of inflightTx
+ *
+ * Rather than doing that, we keep this method synchronized, hence performing only:
+ * 1) take lock
+ * 2) CAS of inflightTx
+ *
+ * Since the user thread is barred from submitting the transaction (in processIfReady), we can then proceed with
+ * the knowledge that inflightTx is null -- processTransaction() will still do a CAS, but that is only for
+ * correctness.
+ */
+ private synchronized void processNextTransaction(final PingPongTransaction tx) {
final boolean success = INFLIGHT_UPDATER.compareAndSet(this, tx, null);
- Preconditions.checkState(success, "Successful transaction %s while %s was submitted", tx, inflightTx);
+ checkState(success, "Completed transaction %s while %s was submitted", tx, inflightTx);
- synchronized (this) {
- processIfReady();
+ final PingPongTransaction nextTx = READY_UPDATER.getAndSet(this, null);
+ if (nextTx != null) {
+ processTransaction(nextTx);
+ } else if (shutdownTx != null) {
+ processTransaction(shutdownTx);
+ delegate.close();
+ shutdownTx = null;
}
+ }
+
+ void transactionSuccessful(final PingPongTransaction tx, final CommitInfo result) {
+ LOG.debug("Transaction {} completed successfully", tx);
- // Can run unsynchronized
tx.onSuccess(result);
+ processNextTransaction(tx);
}
- private void transactionFailed(final PingPongTransaction tx, final Throwable t) {
- LOG.debug("Transaction {} failed", tx, t);
-
- final boolean success = INFLIGHT_UPDATER.compareAndSet(this, tx, null);
- Preconditions.checkState(success, "Failed transaction %s while %s was submitted", tx, inflightTx);
+ void transactionFailed(final PingPongTransaction tx, final Throwable throwable) {
+ LOG.debug("Transaction {} failed", tx, throwable);
- tx.onFailure(t);
+ tx.onFailure(throwable);
+ processNextTransaction(tx);
}
- private void readyTransaction(final @Nonnull PingPongTransaction tx) {
+ void readyTransaction(final @NonNull PingPongTransaction tx) {
// First mark the transaction as not locked.
final boolean lockedMatch = LOCKED_UPDATER.compareAndSet(this, tx, null);
- Preconditions.checkState(lockedMatch, "Attempted to submit transaction %s while we have %s", tx, lockedTx);
+ checkState(lockedMatch, "Attempted to submit transaction %s while we have %s", tx, lockedTx);
LOG.debug("Transaction {} unlocked", tx);
/*
@@ -234,7 +314,7 @@ public final class PingPongTransactionChain implements DOMTransactionChain {
* or a background transaction completion callback.
*/
final boolean success = READY_UPDATER.compareAndSet(this, null, tx);
- Preconditions.checkState(success, "Transaction %s collided on ready state", tx, readyTx);
+ checkState(success, "Transaction %s collided on ready state", tx, readyTx);
LOG.debug("Transaction {} readied", tx);
/*
@@ -250,13 +330,83 @@ public final class PingPongTransactionChain implements DOMTransactionChain {
}
}
+ /**
+ * Transaction cancellation is a heavyweight operation. We only support cancelation of a locked transaction
+ * and return false for everything else. Cancelling such a transaction will result in all transactions in the
+ * batch to be cancelled.
+ *
+ * @param tx Backend shared transaction
+ * @param frontendTx transaction
+ * @param isOpen indicator whether the transaction was already closed
+ */
+ synchronized void cancelTransaction(final PingPongTransaction tx, final DOMDataReadWriteTransaction frontendTx) {
+ // Attempt to unlock the operation.
+ final boolean lockedMatch = LOCKED_UPDATER.compareAndSet(this, tx, null);
+ verify(lockedMatch, "Cancelling transaction %s collided with locked transaction %s", tx, lockedTx);
+
+ // Cancel the backend transaction, so we do not end up leaking it.
+ final boolean backendCancelled = tx.getTransaction().cancel();
+
+ if (failed) {
+ // The transaction has failed, this is probably the user just clearing up the transaction they had. We have
+ // already cancelled the transaction anyway,
+ return;
+ } else if (!backendCancelled) {
+ LOG.warn("Backend transaction cannot be cancelled during cancellation of {}, attempting to continue", tx);
+ }
+
+ // We have dealt with canceling the backend transaction and have unlocked the transaction. Since we are still
+ // inside the synchronized block, any allocations are blocking on the slow path. Now we have to decide the fate
+ // of this transaction chain.
+ //
+ // If there are no other frontend transactions in this batch we are aligned with backend state and we can
+ // continue processing.
+ if (frontendTx.equals(tx.getFrontendTransaction())) {
+ LOG.debug("Cancelled transaction {} was head of the batch, resuming processing", tx);
+ return;
+ }
+
+ // There are multiple frontend transactions in this batch. We have to report them as failed, which dooms this
+ // transaction chain, too. Since we just came off of a locked transaction, we do not have a ready transaction
+ // at the moment, but there may be some transaction in-flight. So we proceed to shutdown the backend chain
+ // and mark the fact that we should be turning its completion into a failure.
+ deadTx = new SimpleImmutableEntry<>(tx, new CancellationException("Transaction " + frontendTx + " canceled")
+ .fillInStackTrace());
+ delegate.close();
+ }
+
@Override
- public void close() {
+ public synchronized void close() {
final PingPongTransaction notLocked = lockedTx;
- Preconditions.checkState(notLocked == null, "Attempted to close chain with outstanding transaction %s", notLocked);
+ checkState(notLocked == null, "Attempted to close chain with outstanding transaction %s", notLocked);
- synchronized (this) {
- processIfReady();
+ // This is not reliable, but if we observe it to be null and the process has already completed,
+ // the backend transaction chain will throw the appropriate error.
+ checkState(shutdownTx == null, "Attempted to close an already-closed chain");
+
+ // This may be a reaction to our failure callback, in that case the backend is already shutdown
+ if (deadTx != null) {
+ LOG.debug("Delegate {} is already closed due to failure {}", delegate, deadTx);
+ return;
+ }
+
+ // Force allocations on slow path, picking up a potentially-outstanding transaction
+ final PingPongTransaction tx = READY_UPDATER.getAndSet(this, null);
+
+ if (tx != null) {
+ // We have one more transaction, which needs to be processed somewhere. If we do not
+ // a transaction in-flight, we need to push it down ourselves.
+ // If there is an in-flight transaction we will schedule this last one into a dedicated
+ // slot. Allocation slow path will check its presence and fail, the in-flight path will
+ // pick it up, submit and immediately close the chain.
+ if (inflightTx == null) {
+ processTransaction(tx);
+ delegate.close();
+ } else {
+ shutdownTx = tx;
+ }
+ } else {
+ // Nothing outstanding, we can safely shutdown
delegate.close();
}
}
@@ -267,14 +417,14 @@ public final class PingPongTransactionChain implements DOMTransactionChain {
return new DOMDataReadOnlyTransaction() {
@Override
- public CheckedFuture>, ReadFailedException> read(final LogicalDatastoreType store,
- final YangInstanceIdentifier path) {
+ public CheckedFuture>, ReadFailedException> read(
+ final LogicalDatastoreType store, final YangInstanceIdentifier path) {
return tx.getTransaction().read(store, path);
}
@Override
public CheckedFuture exists(final LogicalDatastoreType store,
- final YangInstanceIdentifier path) {
+ final YangInstanceIdentifier path) {
return tx.getTransaction().exists(store, path);
}
@@ -294,26 +444,30 @@ public final class PingPongTransactionChain implements DOMTransactionChain {
public DOMDataReadWriteTransaction newReadWriteTransaction() {
final PingPongTransaction tx = allocateTransaction();
final DOMDataReadWriteTransaction ret = new ForwardingDOMDataReadWriteTransaction() {
+ private boolean isOpen = true;
+
@Override
protected DOMDataReadWriteTransaction delegate() {
return tx.getTransaction();
}
@Override
- public CheckedFuture submit() {
+ public FluentFuture commit() {
readyTransaction(tx);
- return tx.getSubmitFuture();
- }
-
- @Override
- public ListenableFuture> commit() {
- readyTransaction(tx);
- return tx.getCommitFuture();
+ isOpen = false;
+ return FluentFuture.from(tx.getCommitFuture()).transformAsync(
+ ignored -> CommitInfo.emptyFluentFuture(), MoreExecutors.directExecutor());
}
@Override
public boolean cancel() {
- throw new UnsupportedOperationException("Transaction cancellation is not supported");
+ if (isOpen) {
+ cancelTransaction(tx, this);
+ isOpen = false;
+ return true;
+ } else {
+ return false;
+ }
}
};