X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-distributed-datastore%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fcluster%2Fdatastore%2FShardDataTree.java;h=a04bf62a96d9e964208e0ac76cd29f104df649a6;hb=refs%2Fchanges%2F75%2F28775%2F21;hp=f1d37872fd20262ae4e3c114f8ad96c6cf7e7e75;hpb=6276a65120a674b545ea787a5e1d9311bcdbf2af;p=controller.git diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardDataTree.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardDataTree.java index f1d37872fd..a04bf62a96 100644 --- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardDataTree.java +++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardDataTree.java @@ -13,11 +13,14 @@ import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.google.common.base.Stopwatch; +import com.google.common.base.Ticker; import com.google.common.base.Verify; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import com.google.common.collect.ImmutableMap.Builder; import com.google.common.primitives.UnsignedLong; +import edu.umd.cs.findbugs.annotations.SuppressFBWarnings; +import java.io.File; import java.io.IOException; import java.util.AbstractMap.SimpleEntry; import java.util.ArrayDeque; @@ -42,6 +45,7 @@ import org.opendaylight.controller.cluster.datastore.persisted.CommitTransaction import org.opendaylight.controller.cluster.datastore.persisted.MetadataShardDataTreeSnapshot; import org.opendaylight.controller.cluster.datastore.persisted.ShardDataTreeSnapshot; import org.opendaylight.controller.cluster.datastore.persisted.ShardDataTreeSnapshotMetadata; +import org.opendaylight.controller.cluster.datastore.utils.DataTreeModificationOutput; import org.opendaylight.controller.cluster.datastore.utils.PruningDataTreeModification; import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload; import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker.DataChangeScope; @@ -60,9 +64,11 @@ import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateTip import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidates; import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification; import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot; +import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeTip; import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException; import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType; import org.opendaylight.yangtools.yang.data.api.schema.tree.TipProducingDataTree; +import org.opendaylight.yangtools.yang.data.api.schema.tree.TipProducingDataTreeTip; import org.opendaylight.yangtools.yang.data.api.schema.tree.TreeType; import org.opendaylight.yangtools.yang.data.impl.schema.tree.InMemoryDataTreeFactory; import org.opendaylight.yangtools.yang.model.api.SchemaContext; @@ -75,6 +81,7 @@ import scala.concurrent.duration.Duration; * e.g. it does not expose public interfaces and assumes it is only ever called from a * single thread. * + *

* This class is not part of the API contract and is subject to change at any time. */ @NotThreadSafe @@ -103,6 +110,14 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { private final Shard shard; private Runnable runOnPendingTransactionsComplete; + /** + * Optimistic {@link DataTreeCandidate} preparation. Since our DataTree implementation is a + * {@link TipProducingDataTree}, each {@link DataTreeCandidate} is also a {@link DataTreeTip}, e.g. another + * candidate can be prepared on top of it. They still need to be committed in sequence. Here we track the current + * tip of the data tree, which is the last DataTreeCandidate we have in flight, or the DataTree itself. + */ + private TipProducingDataTreeTip tip; + private SchemaContext schemaContext; public ShardDataTree(final Shard shard, final SchemaContext schemaContext, final TipProducingDataTree dataTree, @@ -117,6 +132,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { this.dataChangeListenerPublisher = Preconditions.checkNotNull(dataChangeListenerPublisher); this.logContext = Preconditions.checkNotNull(logContext); this.metadata = ImmutableList.copyOf(metadata); + tip = dataTree; } public ShardDataTree(final Shard shard, final SchemaContext schemaContext, final TreeType treeType, @@ -132,10 +148,14 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { new DefaultShardDataChangeListenerPublisher(), ""); } - String logContext() { + final String logContext() { return logContext; } + final Ticker ticker() { + return shard.ticker(); + } + public TipProducingDataTree getDataTree() { return dataTree; } @@ -144,9 +164,9 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { return schemaContext; } - void updateSchemaContext(final SchemaContext schemaContext) { - dataTree.setSchemaContext(schemaContext); - this.schemaContext = Preconditions.checkNotNull(schemaContext); + void updateSchemaContext(final SchemaContext newSchemaContext) { + dataTree.setSchemaContext(newSchemaContext); + this.schemaContext = Preconditions.checkNotNull(newSchemaContext); } /** @@ -160,7 +180,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { ImmutableMap.builder(); for (ShardDataTreeMetadata m : metadata) { - final ShardDataTreeSnapshotMetadata meta = m.toStapshot(); + final ShardDataTreeSnapshotMetadata meta = m.toSnapshot(); if (meta != null) { metaBuilder.put(meta.getType(), meta); } @@ -169,7 +189,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { return new MetadataShardDataTreeSnapshot(rootNode, metaBuilder.build()); } - private void applySnapshot(final @Nonnull ShardDataTreeSnapshot snapshot, + private void applySnapshot(@Nonnull final ShardDataTreeSnapshot snapshot, final UnaryOperator wrapper) throws DataValidationFailedException { final Stopwatch elapsed = Stopwatch.createStarted(); @@ -206,10 +226,24 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { final DataTreeModification unwrapped = unwrap(mod); dataTree.validate(unwrapped); - dataTree.commit(dataTree.prepare(unwrapped)); + DataTreeCandidateTip candidate = dataTree.prepare(unwrapped); + dataTree.commit(candidate); + notifyListeners(candidate); + LOG.debug("{}: state snapshot applied in %s", logContext, elapsed); } + /** + * Apply a snapshot coming from the leader. This method assumes the leader and follower SchemaContexts match and + * does not perform any pruning. + * + * @param snapshot Snapshot that needs to be applied + * @throws DataValidationFailedException when the snapshot fails to apply + */ + void applySnapshot(@Nonnull final ShardDataTreeSnapshot snapshot) throws DataValidationFailedException { + applySnapshot(snapshot, UnaryOperator.identity()); + } + private PruningDataTreeModification wrapWithPruning(final DataTreeModification delegate) { return new PruningDataTreeModification(delegate, dataTree, schemaContext); } @@ -232,18 +266,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { applySnapshot(snapshot, this::wrapWithPruning); } - - /** - * Apply a snapshot coming from the leader. This method assumes the leader and follower SchemaContexts match and - * does not perform any pruning. - * - * @param snapshot Snapshot that needs to be applied - * @throws DataValidationFailedException when the snapshot fails to apply - */ - void applySnapshot(final @Nonnull ShardDataTreeSnapshot snapshot) throws DataValidationFailedException { - applySnapshot(snapshot, UnaryOperator.identity()); - } - + @SuppressWarnings("checkstyle:IllegalCatch") private void applyRecoveryCandidate(final DataTreeCandidate candidate) throws DataValidationFailedException { final PruningDataTreeModification mod = wrapWithPruning(dataTree.takeSnapshot().newModification()); DataTreeCandidates.applyToModification(mod, candidate); @@ -252,8 +275,17 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { final DataTreeModification unwrapped = mod.delegate(); LOG.trace("{}: Applying recovery modification {}", logContext, unwrapped); - dataTree.validate(unwrapped); - dataTree.commit(dataTree.prepare(unwrapped)); + try { + dataTree.validate(unwrapped); + dataTree.commit(dataTree.prepare(unwrapped)); + } catch (Exception e) { + File file = new File(System.getProperty("karaf.data", "."), + "failed-recovery-payload-" + logContext + ".out"); + DataTreeModificationOutput.toFile(file, unwrapped); + throw new IllegalStateException(String.format( + "%s: Failed to apply recovery payload. Modification data was written to file %s", + logContext, file), e); + } } /** @@ -266,13 +298,14 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { */ void applyRecoveryPayload(final @Nonnull Payload payload) throws IOException, DataValidationFailedException { if (payload instanceof CommitTransactionPayload) { - final Entry e = ((CommitTransactionPayload) payload).getCandidate(); + final Entry e = + ((CommitTransactionPayload) payload).getCandidate(); applyRecoveryCandidate(e.getValue()); allMetadataCommittedTransaction(e.getKey()); } else if (payload instanceof DataTreeCandidatePayload) { applyRecoveryCandidate(((DataTreeCandidatePayload) payload).getCandidate()); } else { - LOG.warn("{}: ignoring unhandled payload {}", logContext, payload); + LOG.debug("{}: ignoring unhandled payload {}", logContext, payload); } } @@ -316,7 +349,8 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { */ if (payload instanceof CommitTransactionPayload) { if (identifier == null) { - final Entry e = ((CommitTransactionPayload) payload).getCandidate(); + final Entry e = + ((CommitTransactionPayload) payload).getCandidate(); applyReplicatedCandidate(e.getKey(), e.getValue()); allMetadataCommittedTransaction(e.getKey()); } else { @@ -346,11 +380,11 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { private void allMetadataCommittedTransaction(final TransactionIdentifier txId) { for (ShardDataTreeMetadata m : metadata) { - m.transactionCommitted(txId); + m.onTransactionCommitted(txId); } } - private ShardDataTreeTransactionChain ensureTransactionChain(final LocalHistoryIdentifier localHistoryIdentifier) { + ShardDataTreeTransactionChain ensureTransactionChain(final LocalHistoryIdentifier localHistoryIdentifier) { ShardDataTreeTransactionChain chain = transactionChains.get(localHistoryIdentifier); if (chain == null) { chain = new ShardDataTreeTransactionChain(localHistoryIdentifier, this); @@ -377,6 +411,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { return ensureTransactionChain(txId.getHistoryId()).newReadWriteTransaction(txId); } + @VisibleForTesting public void notifyListeners(final DataTreeCandidate candidate) { treeChangeListenerPublisher.publishChanges(candidate, logContext); dataChangeListenerPublisher.publishChanges(candidate, logContext); @@ -422,22 +457,23 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { Optional> registerChangeListener(final YangInstanceIdentifier path, final AsyncDataChangeListener> listener, final DataChangeScope scope) { - final DataChangeListenerRegistration>> reg = + DataChangeListenerRegistration>> reg = dataChangeListenerPublisher.registerDataChangeListener(path, listener, scope); return new SimpleEntry<>(reg, readCurrentData()); } private Optional readCurrentData() { - final Optional> currentState = dataTree.takeSnapshot().readNode(YangInstanceIdentifier.EMPTY); + final Optional> currentState = + dataTree.takeSnapshot().readNode(YangInstanceIdentifier.EMPTY); return currentState.isPresent() ? Optional.of(DataTreeCandidates.fromNormalizedNode( YangInstanceIdentifier.EMPTY, currentState.get())) : Optional.absent(); } - public Entry, Optional> registerTreeChangeListener( - final YangInstanceIdentifier path, final DOMDataTreeChangeListener listener) { - final ListenerRegistration reg = treeChangeListenerPublisher.registerTreeChangeListener( - path, listener); + public Entry, Optional> + registerTreeChangeListener(final YangInstanceIdentifier path, final DOMDataTreeChangeListener listener) { + final ListenerRegistration reg = + treeChangeListenerPublisher.registerTreeChangeListener(path, listener); return new SimpleEntry<>(reg, readCurrentData()); } @@ -456,27 +492,33 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { final DataTreeModification snapshot = transaction.getSnapshot(); snapshot.ready(); - return createReadyCohort(transaction.getId(), snapshot); + return createReadyCohort(transaction.getIdentifier(), snapshot); } public Optional> readNode(final YangInstanceIdentifier path) { return dataTree.takeSnapshot().readNode(path); } - public DataTreeSnapshot takeSnapshot() { + DataTreeSnapshot takeSnapshot() { return dataTree.takeSnapshot(); } + @VisibleForTesting public DataTreeModification newModification() { return dataTree.takeSnapshot().newModification(); } /** + * Commits a modification. + * * @deprecated This method violates DataTree containment and will be removed. */ @VisibleForTesting @Deprecated public DataTreeCandidate commit(final DataTreeModification modification) throws DataValidationFailedException { + // Direct modification commit is a utility, which cannot be used while we have transactions in-flight + Preconditions.checkState(tip == dataTree, "Cannot modify data tree while transacgitons are pending"); + modification.ready(); dataTree.validate(modification); DataTreeCandidate candidate = dataTree.prepare(modification); @@ -486,28 +528,30 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { public Collection getAndClearPendingTransactions() { Collection ret = new ArrayList<>(pendingTransactions.size()); - for(CommitEntry entry: pendingTransactions) { + for (CommitEntry entry: pendingTransactions) { ret.add(entry.cohort); } pendingTransactions.clear(); + tip = dataTree; return ret; } + @SuppressWarnings("checkstyle:IllegalCatch") private void processNextTransaction() { while (!pendingTransactions.isEmpty()) { final CommitEntry entry = pendingTransactions.peek(); final SimpleShardDataTreeCohort cohort = entry.cohort; final DataTreeModification modification = cohort.getDataTreeModification(); - if(cohort.getState() != State.CAN_COMMIT_PENDING) { + if (cohort.getState() != State.CAN_COMMIT_PENDING) { break; } LOG.debug("{}: Validating transaction {}", logContext, cohort.getIdentifier()); Exception cause; try { - dataTree.validate(modification); + tip.validate(modification); LOG.debug("{}: Transaction {} validated", logContext, cohort.getIdentifier()); cohort.successfulCanCommit(); entry.lastAccess = shard.ticker().read(); @@ -522,7 +566,8 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { // For debugging purposes, allow dumping of the modification. Coupled with the above // precondition log, it should allow us to understand what went on. - LOG.debug("{}: Store Tx {}: modifications: {} tree: {}", cohort.getIdentifier(), modification, dataTree); + LOG.debug("{}: Store Tx {}: modifications: {} tree: {}", cohort.getIdentifier(), modification, + dataTree); cause = new TransactionCommitFailedException("Data did not pass validation.", e); } catch (Exception e) { LOG.warn("{}: Unexpected failure in validation phase", logContext, e); @@ -552,6 +597,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { processNextTransaction(); } + @SuppressWarnings("checkstyle:IllegalCatch") void startPreCommit(final SimpleShardDataTreeCohort cohort) { final CommitEntry entry = pendingTransactions.peek(); Preconditions.checkState(entry != null, "Attempted to pre-commit of %s when no transactions pending", cohort); @@ -560,7 +606,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { Verify.verify(cohort.equals(current), "Attempted to pre-commit %s while %s is pending", cohort, current); final DataTreeCandidateTip candidate; try { - candidate = dataTree.prepare(cohort.getDataTreeModification()); + candidate = tip.prepare(cohort.getDataTreeModification()); } catch (Exception e) { failPreCommit(e); return; @@ -573,6 +619,9 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { return; } + // Set the tip of the data tree. + tip = Verify.verifyNotNull(candidate); + entry.lastAccess = shard.ticker().read(); cohort.successfulPreCommit(candidate); } @@ -583,6 +632,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { processNextTransaction(); } + @SuppressWarnings("checkstyle:IllegalCatch") private void finishCommit(final SimpleShardDataTreeCohort cohort) { final TransactionIdentifier txId = cohort.getIdentifier(); final DataTreeCandidate candidate = cohort.getCandidate(); @@ -597,6 +647,11 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { return; } + // All pending candidates have been committed, reset the tip to the data tree + if (tip == candidate) { + tip = dataTree; + } + shard.getShardMBean().incrementCommittedTransactionCount(); shard.getShardMBean().setLastCommittedTransactionTime(System.currentTimeMillis()); @@ -642,6 +697,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { cohortRegistry.process(sender, message); } + @Override ShardDataTreeCohort createReadyCohort(final TransactionIdentifier txId, final DataTreeModification modification) { SimpleShardDataTreeCohort cohort = new SimpleShardDataTreeCohort(this, modification, txId, @@ -650,6 +706,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { return cohort; } + @SuppressFBWarnings(value = "DB_DUPLICATE_SWITCH_CLAUSES", justification = "See inline comments below.") void checkForExpiredTransactions(final long transactionCommitTimeoutMillis) { final long timeout = TimeUnit.MILLISECONDS.toNanos(transactionCommitTimeoutMillis); final long now = shard.ticker().read(); @@ -660,13 +717,16 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { boolean processNext = true; switch (currentTx.cohort.getState()) { case CAN_COMMIT_PENDING: - pendingTransactions.poll().cohort.failedCanCommit(new TimeoutException()); + pendingTransactions.remove().cohort.failedCanCommit(new TimeoutException()); break; case CAN_COMMIT_COMPLETE: - pendingTransactions.poll().cohort.reportFailure(new TimeoutException()); + // The suppression of the FindBugs "DB_DUPLICATE_SWITCH_CLAUSES" warning pertains to this clause + // whose code is duplicated with PRE_COMMIT_COMPLETE. The clauses aren't combined in case the code + // in PRE_COMMIT_COMPLETE is changed. + pendingTransactions.remove().cohort.reportFailure(new TimeoutException()); break; case PRE_COMMIT_PENDING: - pendingTransactions.poll().cohort.failedPreCommit(new TimeoutException()); + pendingTransactions.remove().cohort.failedPreCommit(new TimeoutException()); break; case PRE_COMMIT_COMPLETE: // FIXME: this is a legacy behavior problem. Three-phase commit protocol specifies that after we @@ -686,7 +746,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { // In order to make the pre-commit timer working across failovers, though, we need // a per-shard cluster-wide monotonic time, so a follower becoming the leader can accurately // restart the timer. - pendingTransactions.poll().cohort.reportFailure(new TimeoutException()); + pendingTransactions.remove().cohort.reportFailure(new TimeoutException()); break; case COMMIT_PENDING: LOG.warn("{}: Transaction {} is still committing, cannot abort", logContext, @@ -699,7 +759,7 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { case FAILED: case READY: default: - pendingTransactions.poll(); + pendingTransactions.remove(); } if (processNext) { @@ -708,38 +768,77 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { } } - void startAbort(final SimpleShardDataTreeCohort cohort) { + boolean startAbort(final SimpleShardDataTreeCohort cohort) { final Iterator it = pendingTransactions.iterator(); if (!it.hasNext()) { LOG.debug("{}: no open transaction while attempting to abort {}", logContext, cohort.getIdentifier()); - return; + return true; } // First entry is special, as it may already be committing final CommitEntry first = it.next(); if (cohort.equals(first.cohort)) { if (cohort.getState() != State.COMMIT_PENDING) { - LOG.debug("{}: aborted head of queue {} in state {}", logContext, cohort.getIdentifier(), + LOG.debug("{}: aborting head of queue {} in state {}", logContext, cohort.getIdentifier(), cohort.getIdentifier()); - pendingTransactions.poll(); + + it.remove(); + rebasePreCommittedTransactions(it, dataTree); processNextTransaction(); - } else { - LOG.warn("{}: transaction {} is committing, skipping abort", logContext, cohort.getIdentifier()); + return true; } - return; + LOG.warn("{}: transaction {} is committing, skipping abort", logContext, cohort.getIdentifier()); + return false; } + TipProducingDataTreeTip newTip = dataTree; while (it.hasNext()) { final CommitEntry e = it.next(); if (cohort.equals(e.cohort)) { LOG.debug("{}: aborting queued transaction {}", logContext, cohort.getIdentifier()); it.remove(); - return; + rebasePreCommittedTransactions(it, newTip); + return true; + } else { + newTip = cohort.getCandidate(); } } LOG.debug("{}: aborted transaction {} not found in the queue", logContext, cohort.getIdentifier()); + return true; + } + + @SuppressWarnings("checkstyle:IllegalCatch") + private void rebasePreCommittedTransactions(Iterator iter, TipProducingDataTreeTip newTip) { + tip = newTip; + while (iter.hasNext()) { + final SimpleShardDataTreeCohort cohort = iter.next().cohort; + if (cohort.getState() == State.CAN_COMMIT_COMPLETE) { + LOG.debug("{}: Revalidating queued transaction {}", logContext, cohort.getIdentifier()); + + try { + tip.validate(cohort.getDataTreeModification()); + } catch (DataValidationFailedException | RuntimeException e) { + LOG.debug("{}: Failed to revalidate queued transaction {}", logContext, cohort.getIdentifier(), e); + cohort.reportFailure(e); + } + } else if (cohort.getState() == State.PRE_COMMIT_COMPLETE) { + LOG.debug("{}: Repreparing queued transaction {}", logContext, cohort.getIdentifier()); + + try { + tip.validate(cohort.getDataTreeModification()); + DataTreeCandidateTip candidate = tip.prepare(cohort.getDataTreeModification()); + cohort.userPreCommit(candidate); + + cohort.setNewCandidate(candidate); + tip = candidate; + } catch (ExecutionException | TimeoutException | RuntimeException | DataValidationFailedException e) { + LOG.debug("{}: Failed to reprepare queued transaction {}", logContext, cohort.getIdentifier(), e); + cohort.reportFailure(e); + } + } + } } void setRunOnPendingTransactionsComplete(final Runnable operation) { @@ -748,12 +847,12 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { } private void maybeRunOperationOnPendingTransactionsComplete() { - if (runOnPendingTransactionsComplete != null && pendingTransactions.isEmpty()) { - LOG.debug("{}: Pending transactions complete - running operation {}", logContext, - runOnPendingTransactionsComplete); - - runOnPendingTransactionsComplete.run(); - runOnPendingTransactionsComplete = null; - } - } + if (runOnPendingTransactionsComplete != null && pendingTransactions.isEmpty()) { + LOG.debug("{}: Pending transactions complete - running operation {}", logContext, + runOnPendingTransactionsComplete); + + runOnPendingTransactionsComplete.run(); + runOnPendingTransactionsComplete = null; + } + } }