2 * Copyright (c) 2020 PANTHEON.tech, s.r.o. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.yangtools.yang.parser.stmt.reactor;
10 import static com.google.common.base.Verify.verify;
12 import com.google.common.base.MoreObjects;
13 import com.google.common.base.MoreObjects.ToStringHelper;
14 import com.google.common.base.VerifyException;
15 import java.util.Collection;
17 import java.util.Optional;
19 import org.eclipse.jdt.annotation.NonNull;
20 import org.eclipse.jdt.annotation.Nullable;
21 import org.opendaylight.yangtools.yang.common.QName;
22 import org.opendaylight.yangtools.yang.common.YangVersion;
23 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
24 import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
25 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
26 import org.opendaylight.yangtools.yang.model.api.meta.IdentifierNamespace;
27 import org.opendaylight.yangtools.yang.model.api.meta.StatementDefinition;
28 import org.opendaylight.yangtools.yang.model.api.stmt.AugmentStatement;
29 import org.opendaylight.yangtools.yang.model.api.stmt.ConfigEffectiveStatement;
30 import org.opendaylight.yangtools.yang.model.api.stmt.DeviationStatement;
31 import org.opendaylight.yangtools.yang.model.api.stmt.RefineStatement;
32 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier;
33 import org.opendaylight.yangtools.yang.model.api.stmt.UsesStatement;
34 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
35 import org.opendaylight.yangtools.yang.parser.spi.meta.CommonStmtCtx;
36 import org.opendaylight.yangtools.yang.parser.spi.meta.EffectiveStmtCtx.Current;
37 import org.opendaylight.yangtools.yang.parser.spi.meta.InferenceException;
38 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelActionBuilder;
39 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelProcessingPhase;
40 import org.opendaylight.yangtools.yang.parser.spi.meta.MutableStatement;
41 import org.opendaylight.yangtools.yang.parser.spi.meta.NamespaceBehaviour.Registry;
42 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext;
43 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext.Mutable;
44 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContextUtils;
45 import org.opendaylight.yangtools.yang.parser.spi.source.SourceException;
46 import org.opendaylight.yangtools.yang.parser.spi.source.SupportedFeaturesNamespace;
47 import org.opendaylight.yangtools.yang.parser.spi.source.SupportedFeaturesNamespace.SupportedFeatures;
48 import org.slf4j.Logger;
49 import org.slf4j.LoggerFactory;
52 * Real "core" reactor statement implementation of {@link Mutable}, supporting basic reactor lifecycle.
54 * @param <A> Argument type
55 * @param <D> Declared Statement representation
56 * @param <E> Effective Statement representation
58 abstract class ReactorStmtCtx<A, D extends DeclaredStatement<A>, E extends EffectiveStatement<A, D>>
59 extends NamespaceStorageSupport implements Mutable<A, D, E>, Current<A, D> {
60 private static final Logger LOG = LoggerFactory.getLogger(ReactorStmtCtx.class);
63 * Substatement refcount tracking. This mechanics deals with retaining substatements for the purposes of
64 * instantiating their lazy copies in InferredStatementContext. It works in concert with {@link #buildEffective()}
65 * and {@link #declared()}: declared/effective statement views hold an implicit reference and refcount-based
66 * sweep is not activated until they are done (or this statement is not {@link #isSupportedToBuildEffective}).
69 * Reference count is hierarchical in that parent references also pin down their child statements and do not allow
73 * The counter's positive values are tracking incoming references via {@link #incRef()}/{@link #decRef()} methods.
74 * Once we transition to sweeping, this value becomes negative counting upwards to {@link #REFCOUNT_NONE} based on
75 * {@link #sweepOnChildDone()}. Once we reach that, we transition to {@link #REFCOUNT_SWEPT}.
77 private int refcount = REFCOUNT_NONE;
79 * No outstanding references, this statement is a potential candidate for sweeping, provided it has populated its
80 * declared and effective views and {@link #parentRef} is known to be absent.
82 private static final int REFCOUNT_NONE = 0;
84 * Reference count overflow or some other recoverable logic error. Do not rely on refcounts and do not sweep
88 * Note on value assignment:
89 * This allow our incRef() to naturally progress to being saturated. Others jump there directly.
90 * It also makes it it impossible to observe {@code Interger.MAX_VALUE} children, which we take advantage of for
91 * {@link #REFCOUNT_SWEEPING}.
93 private static final int REFCOUNT_DEFUNCT = Integer.MAX_VALUE;
95 * This statement is being actively swept. This is a transient value set when we are sweeping our children, so that
96 * we prevent re-entering this statement.
99 * Note on value assignment:
100 * The value is lower than any legal child refcount due to {@link #REFCOUNT_DEFUNCT} while still being higher than
101 * {@link #REFCOUNT_SWEPT}.
103 private static final int REFCOUNT_SWEEPING = -Integer.MAX_VALUE;
105 * This statement, along with its entire subtree has been swept and we positively know all our children have reached
106 * this state. We {@link #sweepNamespaces()} upon reaching this state.
109 * Note on value assignment:
110 * This is the lowest value observable, making it easier on checking others on equality.
112 private static final int REFCOUNT_SWEPT = Integer.MIN_VALUE;
114 private @Nullable E effectiveInstance;
116 // Master flag controlling whether this context can yield an effective statement
117 // FIXME: investigate the mechanics that are being supported by this, as it would be beneficial if we can get rid
118 // of this flag -- eliminating the initial alignment shadow used by below gap-filler fields.
119 private boolean isSupportedToBuildEffective = true;
121 // Flag bit assignments
122 private static final int IS_SUPPORTED_BY_FEATURES = 0x01;
123 private static final int HAVE_SUPPORTED_BY_FEATURES = 0x02;
124 private static final int IS_IGNORE_IF_FEATURE = 0x04;
125 private static final int HAVE_IGNORE_IF_FEATURE = 0x08;
126 // Note: these four are related
127 private static final int IS_IGNORE_CONFIG = 0x10;
128 private static final int HAVE_IGNORE_CONFIG = 0x20;
129 private static final int IS_CONFIGURATION = 0x40;
130 private static final int HAVE_CONFIGURATION = 0x80;
132 // Have-and-set flag constants, also used as masks
133 private static final int SET_SUPPORTED_BY_FEATURES = HAVE_SUPPORTED_BY_FEATURES | IS_SUPPORTED_BY_FEATURES;
134 private static final int SET_CONFIGURATION = HAVE_CONFIGURATION | IS_CONFIGURATION;
135 // Note: implies SET_CONFIGURATION, allowing fewer bit operations to be performed
136 private static final int SET_IGNORE_CONFIG = HAVE_IGNORE_CONFIG | IS_IGNORE_CONFIG | SET_CONFIGURATION;
137 private static final int SET_IGNORE_IF_FEATURE = HAVE_IGNORE_IF_FEATURE | IS_IGNORE_IF_FEATURE;
139 // Flags for use with SubstatementContext. These are hiding in the alignment shadow created by above boolean and
140 // hence improve memory layout.
143 // Flag for use with AbstractResumedStatement. This is hiding in the alignment shadow created by above boolean
144 // FIXME: move this out once we have JDK15+
145 private boolean fullyDefined;
147 // SchemaPath cache for use with SubstatementContext and InferredStatementContext. This hurts RootStatementContext
148 // a bit in terms of size -- but those are only a few and SchemaPath is on its way out anyway.
150 private volatile SchemaPath schemaPath;
156 ReactorStmtCtx(final ReactorStmtCtx<A, D, E> original) {
157 isSupportedToBuildEffective = original.isSupportedToBuildEffective;
158 fullyDefined = original.fullyDefined;
159 flags = original.flags;
164 // Common public interface contracts with simple mechanics. Please keep this in one logical block, so we do not end
165 // up mixing concerns and simple details with more complex logic.
170 public abstract StatementContextBase<?, ?, ?> getParentContext();
173 public abstract RootStatementContext<?, ?, ?> getRoot();
176 public abstract Collection<? extends StatementContextBase<?, ?, ?>> mutableDeclaredSubstatements();
179 public final @NonNull Registry getBehaviourRegistry() {
180 return getRoot().getBehaviourRegistryImpl();
184 public final YangVersion yangVersion() {
185 return getRoot().getRootVersionImpl();
189 public final void setRootVersion(final YangVersion version) {
190 getRoot().setRootVersionImpl(version);
194 public final void addMutableStmtToSeal(final MutableStatement mutableStatement) {
195 getRoot().addMutableStmtToSealImpl(mutableStatement);
199 public final void addRequiredSource(final SourceIdentifier dependency) {
200 getRoot().addRequiredSourceImpl(dependency);
204 public final void setRootIdentifier(final SourceIdentifier identifier) {
205 getRoot().setRootIdentifierImpl(identifier);
209 public final boolean isEnabledSemanticVersioning() {
210 return getRoot().isEnabledSemanticVersioningImpl();
214 public final ModelActionBuilder newInferenceAction(final ModelProcessingPhase phase) {
215 return getRoot().getSourceContext().newInferenceAction(phase);
219 public final StatementDefinition publicDefinition() {
220 return definition().getPublicView();
224 public final Parent effectiveParent() {
225 return getParentContext();
229 public final CommonStmtCtx root() {
234 public final EffectiveStatement<?, ?> original() {
235 return getOriginalCtx().map(StmtContext::buildEffective).orElse(null);
240 @SuppressWarnings("unchecked")
241 public final <Z extends EffectiveStatement<A, D>> StmtContext<A, D, Z> caerbannog() {
242 return (StmtContext<A, D, Z>) this;
246 public final String toString() {
247 return addToStringAttributes(MoreObjects.toStringHelper(this).omitNullValues()).toString();
250 protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
251 return toStringHelper.add("definition", definition()).add("rawArgument", rawArgument());
255 * Return the context in which this statement was defined.
257 * @return statement definition
259 abstract @NonNull StatementDefinitionContext<A, D, E> definition();
263 // NamespaceStorageSupport/Mutable integration methods. Keep these together.
268 public final <K, V, T extends K, N extends IdentifierNamespace<K, V>> V namespaceItem(final Class<@NonNull N> type,
270 return getBehaviourRegistry().getNamespaceBehaviour(type).getFrom(this, key);
274 public final <K, V, N extends IdentifierNamespace<K, V>> Map<K, V> namespace(final Class<@NonNull N> type) {
275 return getNamespace(type);
279 public final <K, V, N extends IdentifierNamespace<K, V>> Map<K, V> localNamespace(final Class<@NonNull N> type) {
280 return getLocalNamespace(type);
284 protected final void checkLocalNamespaceAllowed(final Class<? extends IdentifierNamespace<?, ?>> type) {
285 definition().checkNamespaceAllowed(type);
289 protected <K, V, N extends IdentifierNamespace<K, V>> void onNamespaceElementAdded(final Class<N> type, final K key,
291 // definition().onNamespaceElementAdded(this, type, key, value);
296 // Statement build entry points -- both public and package-private.
301 public final E buildEffective() {
303 return (existing = effectiveInstance) != null ? existing : loadEffective();
306 private E loadEffective() {
307 // Creating an effective statement does not strictly require a declared instance -- there are statements like
308 // 'input', which are implicitly defined.
309 // Our implementation design makes an invariant assumption that buildDeclared() has been called by the time
310 // we attempt to create effective statement:
313 final E ret = effectiveInstance = createEffective();
314 // we have called createEffective(), substatements are no longer guarded by us. Let's see if we can clear up
316 if (refcount == REFCOUNT_NONE) {
322 abstract @NonNull E createEffective();
325 * Try to execute current {@link ModelProcessingPhase} of source parsing. If the phase has already been executed,
326 * this method does nothing.
328 * @param phase to be executed (completed)
329 * @return true if phase was successfully completed
330 * @throws SourceException when an error occurred in source parsing
332 final boolean tryToCompletePhase(final ModelProcessingPhase phase) {
333 return phase.isCompletedBy(getCompletedPhase()) || doTryToCompletePhase(phase);
336 abstract boolean doTryToCompletePhase(ModelProcessingPhase phase);
340 // Flags-based mechanics. These include public interfaces as well as all the crud we have lurking in our alignment
346 public final boolean isSupportedToBuildEffective() {
347 return isSupportedToBuildEffective;
351 public final void setIsSupportedToBuildEffective(final boolean isSupportedToBuildEffective) {
352 this.isSupportedToBuildEffective = isSupportedToBuildEffective;
356 public final boolean isSupportedByFeatures() {
357 final int fl = flags & SET_SUPPORTED_BY_FEATURES;
359 return fl == SET_SUPPORTED_BY_FEATURES;
361 if (isIgnoringIfFeatures()) {
362 flags |= SET_SUPPORTED_BY_FEATURES;
367 * If parent is supported, we need to check if-features statements of this context.
369 if (isParentSupportedByFeatures()) {
370 // If the set of supported features has not been provided, all features are supported by default.
371 final Set<QName> supportedFeatures = getFromNamespace(SupportedFeaturesNamespace.class,
372 SupportedFeatures.SUPPORTED_FEATURES);
373 if (supportedFeatures == null || StmtContextUtils.checkFeatureSupport(this, supportedFeatures)) {
374 flags |= SET_SUPPORTED_BY_FEATURES;
379 // Either parent is not supported or this statement is not supported
380 flags |= HAVE_SUPPORTED_BY_FEATURES;
384 protected abstract boolean isParentSupportedByFeatures();
387 * Config statements are not all that common which means we are performing a recursive search towards the root
388 * every time {@link #isConfiguration()} is invoked. This is quite expensive because it causes a linear search
389 * for the (usually non-existent) config statement.
392 * This method maintains a resolution cache, so once we have returned a result, we will keep on returning the same
393 * result without performing any lookups, solely to support {@link SubstatementContext#isConfiguration()}.
396 * Note: use of this method implies that {@link #isIgnoringConfig()} is realized with
397 * {@link #isIgnoringConfig(StatementContextBase)}.
399 final boolean isConfiguration(final StatementContextBase<?, ?, ?> parent) {
400 final int fl = flags & SET_CONFIGURATION;
402 return fl == SET_CONFIGURATION;
404 if (isIgnoringConfig(parent)) {
405 // Note: SET_CONFIGURATION has been stored in flags
409 final boolean isConfig;
410 final Optional<Boolean> optConfig = findSubstatementArgument(ConfigEffectiveStatement.class);
411 if (optConfig.isPresent()) {
412 isConfig = optConfig.orElseThrow();
414 // Validity check: if parent is config=false this cannot be a config=true
415 InferenceException.throwIf(!parent.effectiveConfig(), this,
416 "Parent node has config=false, this node must not be specifed as config=true");
419 // If "config" statement is not specified, the default is the same as the parent's "config" value.
420 isConfig = parent.effectiveConfig();
423 // Resolved, make sure we cache this return
424 flags |= isConfig ? SET_CONFIGURATION : HAVE_CONFIGURATION;
428 protected abstract boolean isIgnoringConfig();
431 * This method maintains a resolution cache for ignore config, so once we have returned a result, we will
432 * keep on returning the same result without performing any lookups. Exists only to support
433 * {@link SubstatementContext#isIgnoringConfig()}.
436 * Note: use of this method implies that {@link #isConfiguration()} is realized with
437 * {@link #isConfiguration(StatementContextBase)}.
439 final boolean isIgnoringConfig(final StatementContextBase<?, ?, ?> parent) {
440 final int fl = flags & SET_IGNORE_CONFIG;
442 return fl == SET_IGNORE_CONFIG;
444 if (definition().support().isIgnoringConfig() || parent.isIgnoringConfig()) {
445 flags |= SET_IGNORE_CONFIG;
449 flags |= HAVE_IGNORE_CONFIG;
453 protected abstract boolean isIgnoringIfFeatures();
456 * This method maintains a resolution cache for ignore if-feature, so once we have returned a result, we will
457 * keep on returning the same result without performing any lookups. Exists only to support
458 * {@link SubstatementContext#isIgnoringIfFeatures()}.
460 final boolean isIgnoringIfFeatures(final StatementContextBase<?, ?, ?> parent) {
461 final int fl = flags & SET_IGNORE_IF_FEATURE;
463 return fl == SET_IGNORE_IF_FEATURE;
465 if (definition().support().isIgnoringIfFeatures() || parent.isIgnoringIfFeatures()) {
466 flags |= SET_IGNORE_IF_FEATURE;
470 flags |= HAVE_IGNORE_IF_FEATURE;
474 // These two exists only due to memory optimization, should live in AbstractResumedStatement. We are also reusing
475 // this for ReplicaStatementContext's refcount tracking.
476 final boolean fullyDefined() {
480 final void setFullyDefined() {
486 // Common SchemaPath cache. All of this is bound to be removed once YANGTOOLS-1066 is done.
490 // Exists only to support {SubstatementContext,InferredStatementContext}.schemaPath()
492 final @NonNull Optional<SchemaPath> substatementGetSchemaPath() {
493 SchemaPath local = schemaPath;
495 synchronized (this) {
498 schemaPath = local = createSchemaPath((StatementContextBase<?, ?, ?>) coerceParentContext());
503 return Optional.ofNullable(local);
507 private SchemaPath createSchemaPath(final StatementContextBase<?, ?, ?> parent) {
508 final Optional<SchemaPath> maybeParentPath = parent.schemaPath();
509 verify(maybeParentPath.isPresent(), "Parent %s does not have a SchemaPath", parent);
510 final SchemaPath parentPath = maybeParentPath.get();
512 if (StmtContextUtils.isUnknownStatement(this)) {
513 return parentPath.createChild(publicDefinition().getStatementName());
515 final Object argument = argument();
516 if (argument instanceof QName) {
517 final QName qname = (QName) argument;
518 if (producesDeclared(UsesStatement.class)) {
519 return maybeParentPath.orElse(null);
522 return parentPath.createChild(qname);
524 if (argument instanceof String) {
525 // FIXME: This may yield illegal argument exceptions
526 final Optional<StmtContext<A, D, E>> originalCtx = getOriginalCtx();
527 final QName qname = StmtContextUtils.qnameFromArgument(originalCtx.orElse(this), (String) argument);
528 return parentPath.createChild(qname);
530 if (argument instanceof SchemaNodeIdentifier
531 && (producesDeclared(AugmentStatement.class) || producesDeclared(RefineStatement.class)
532 || producesDeclared(DeviationStatement.class))) {
534 return parentPath.createChild(((SchemaNodeIdentifier) argument).getNodeIdentifiers());
537 // FIXME: this does not look right
538 return maybeParentPath.orElse(null);
543 // Reference counting mechanics start. Please keep these methods in one block for clarity. Note this does not
544 // contribute to state visible outside of this package.
549 * Local knowledge of {@link #refcount} values up to statement root. We use this field to prevent recursive lookups
550 * in {@link #noParentRefs(StatementContextBase)} -- once we discover a parent reference once, we keep that
551 * knowledge and update it when {@link #sweep()} is invoked.
553 private byte parentRef = PARENTREF_UNKNOWN;
554 private static final byte PARENTREF_UNKNOWN = -1;
555 private static final byte PARENTREF_ABSENT = 0;
556 private static final byte PARENTREF_PRESENT = 1;
559 * Acquire a reference on this context. As long as there is at least one reference outstanding,
560 * {@link #buildEffective()} will not result in {@link #effectiveSubstatements()} being discarded.
562 * @throws VerifyException if {@link #effectiveSubstatements()} has already been discarded
564 final void incRef() {
565 final int current = refcount;
566 verify(current >= REFCOUNT_NONE, "Attempted to access reference count of %s", this);
567 if (current != REFCOUNT_DEFUNCT) {
568 // Note: can end up becoming REFCOUNT_DEFUNCT on overflow
569 refcount = current + 1;
571 LOG.debug("Disabled refcount increment of {}", this);
576 * Release a reference on this context. This call may result in {@link #effectiveSubstatements()} becoming
579 final void decRef() {
580 final int current = refcount;
581 if (current == REFCOUNT_DEFUNCT) {
583 LOG.debug("Disabled refcount decrement of {}", this);
586 if (current <= REFCOUNT_NONE) {
587 // Underflow, become defunct
588 LOG.warn("Statement refcount underflow, reference counting disabled for {}", this, new Throwable());
589 refcount = REFCOUNT_DEFUNCT;
593 refcount = current - 1;
594 LOG.trace("Refcount {} on {}", refcount, this);
596 if (refcount == REFCOUNT_NONE) {
601 private void lastDecRef() {
602 if (noImplictRef()) {
603 // We are no longer guarded by effective instance
608 final byte prevRefs = parentRef;
609 if (prevRefs == PARENTREF_ABSENT) {
610 // We are the last reference towards root, any children who observed PARENTREF_PRESENT from us need to be
613 } else if (prevRefs == PARENTREF_UNKNOWN) {
614 // Noone observed our parentRef, just update it
615 loadParentRefcount();
619 static final void markNoParentRef(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
620 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
621 final byte prevRef = stmt.parentRef;
622 stmt.parentRef = PARENTREF_ABSENT;
623 if (prevRef == PARENTREF_PRESENT && stmt.refcount == REFCOUNT_NONE) {
624 // Child thinks it is pinned down, update its perspective
625 stmt.markNoParentRef();
630 abstract void markNoParentRef();
632 static final void sweep(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
633 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
639 * Sweep this statement context as a result of {@link #sweepSubstatements()}, i.e. when parent is also being swept.
641 private void sweep() {
642 parentRef = PARENTREF_ABSENT;
643 if (refcount == REFCOUNT_NONE && noImplictRef()) {
644 LOG.trace("Releasing {}", this);
649 static final int countUnswept(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
651 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
652 if (stmt.refcount > REFCOUNT_NONE || !stmt.noImplictRef()) {
660 * Implementation-specific sweep action. This is expected to perform a recursive {@link #sweep(Collection)} on all
661 * {@link #declaredSubstatements()} and {@link #effectiveSubstatements()} and report the result of the sweep
665 * {@link #effectiveSubstatements()} as well as namespaces may become inoperable as a result of this operation.
667 * @return True if the entire tree has been completely swept, false otherwise.
669 abstract int sweepSubstatements();
671 // Called when this statement does not have an implicit reference and have reached REFCOUNT_NONE
672 private void sweepOnDecrement() {
673 LOG.trace("Sweeping on decrement {}", this);
675 // No further parent references, sweep our state.
679 // Propagate towards parent if there is one
680 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
681 if (parent != null) {
682 parent.sweepOnChildDecrement();
686 // Called from child when it has lost its final reference
687 private void sweepOnChildDecrement() {
688 if (isAwaitingChildren()) {
689 // We are a child for which our parent is waiting. Notify it and we are done.
694 // Check parent reference count
695 final int refs = refcount;
696 if (refs > REFCOUNT_NONE || refs <= REFCOUNT_SWEEPING || !noImplictRef()) {
701 // parent is potentially reclaimable
703 LOG.trace("Cleanup {} of parent {}", refcount, this);
705 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
706 if (parent != null) {
707 parent.sweepOnChildDecrement();
713 private boolean noImplictRef() {
714 return effectiveInstance != null || !isSupportedToBuildEffective();
717 private boolean noParentRef() {
718 return parentRefcount() == PARENTREF_ABSENT;
721 private byte parentRefcount() {
723 return (refs = parentRef) != PARENTREF_UNKNOWN ? refs : loadParentRefcount();
726 private byte loadParentRefcount() {
727 return parentRef = calculateParentRefcount();
730 private byte calculateParentRefcount() {
731 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
732 if (parent == null) {
733 return PARENTREF_ABSENT;
735 // There are three possibilities:
736 // - REFCOUNT_NONE, in which case we need to search next parent
737 // - negative (< REFCOUNT_NONE), meaning parent is in some stage of sweeping, hence it does not have
739 // - positive (> REFCOUNT_NONE), meaning parent has an explicit refcount which is holding us down
740 final int refs = parent.refcount;
741 if (refs == REFCOUNT_NONE) {
742 return parent.parentRefcount();
744 return refs < REFCOUNT_NONE ? PARENTREF_ABSENT : PARENTREF_PRESENT;
747 private boolean isAwaitingChildren() {
748 return refcount > REFCOUNT_SWEEPING && refcount < REFCOUNT_NONE;
751 private void sweepOnChildDone() {
752 LOG.trace("Sweeping on child done {}", this);
753 final int current = refcount;
754 if (current >= REFCOUNT_NONE) {
755 // no-op, perhaps we want to handle some cases differently?
756 LOG.trace("Ignoring child sweep of {} for {}", this, current);
759 verify(current != REFCOUNT_SWEPT, "Attempt to sweep a child of swept %s", this);
761 refcount = current + 1;
762 LOG.trace("Child refcount {}", refcount);
763 if (refcount == REFCOUNT_NONE) {
765 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
766 LOG.trace("Propagating to parent {}", parent);
767 if (parent != null && parent.isAwaitingChildren()) {
768 parent.sweepOnChildDone();
773 private void sweepDone() {
774 LOG.trace("Sweep done for {}", this);
775 refcount = REFCOUNT_SWEPT;
779 private boolean sweepState() {
780 refcount = REFCOUNT_SWEEPING;
781 final int childRefs = sweepSubstatements();
782 if (childRefs == 0) {
786 if (childRefs < 0 || childRefs >= REFCOUNT_DEFUNCT) {
787 LOG.warn("Negative child refcount {} cannot be stored, reference counting disabled for {}", childRefs, this,
789 refcount = REFCOUNT_DEFUNCT;
791 LOG.trace("Still {} outstanding children of {}", childRefs, this);
792 refcount = -childRefs;