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 = 0x10;
123 private static final int HAVE_SUPPORTED_BY_FEATURES = 0x20;
124 private static final int IS_IGNORE_IF_FEATURE = 0x40;
125 private static final int HAVE_IGNORE_IF_FEATURE = 0x80;
126 // Have-and-set flag constants, also used as masks
127 private static final int SET_SUPPORTED_BY_FEATURES = HAVE_SUPPORTED_BY_FEATURES | IS_SUPPORTED_BY_FEATURES;
128 private static final int SET_IGNORE_IF_FEATURE = HAVE_IGNORE_IF_FEATURE | IS_IGNORE_IF_FEATURE;
130 // EffectiveConfig mapping
131 private static final int MASK_CONFIG = 0x03;
132 private static final int HAVE_CONFIG = 0x04;
133 private static final EffectiveConfig[] EFFECTIVE_CONFIGS;
136 final EffectiveConfig[] values = EffectiveConfig.values();
137 final int length = values.length;
138 verify(length == 4, "Unexpected EffectiveConfig cardinality %s", length);
139 EFFECTIVE_CONFIGS = values;
142 // Flags for use with SubstatementContext. These are hiding in the alignment shadow created by above boolean and
143 // hence improve memory layout.
146 // Flag for use with AbstractResumedStatement. This is hiding in the alignment shadow created by above boolean
147 // FIXME: move this out once we have JDK15+
148 private boolean fullyDefined;
150 // SchemaPath cache for use with SubstatementContext and InferredStatementContext. This hurts RootStatementContext
151 // a bit in terms of size -- but those are only a few and SchemaPath is on its way out anyway.
153 private volatile SchemaPath schemaPath;
159 ReactorStmtCtx(final ReactorStmtCtx<A, D, E> original) {
160 isSupportedToBuildEffective = original.isSupportedToBuildEffective;
161 fullyDefined = original.fullyDefined;
162 flags = original.flags;
167 // Common public interface contracts with simple mechanics. Please keep this in one logical block, so we do not end
168 // up mixing concerns and simple details with more complex logic.
173 public abstract StatementContextBase<?, ?, ?> getParentContext();
176 public abstract RootStatementContext<?, ?, ?> getRoot();
179 public abstract Collection<? extends StatementContextBase<?, ?, ?>> mutableDeclaredSubstatements();
182 public final @NonNull Registry getBehaviourRegistry() {
183 return getRoot().getBehaviourRegistryImpl();
187 public final YangVersion yangVersion() {
188 return getRoot().getRootVersionImpl();
192 public final void setRootVersion(final YangVersion version) {
193 getRoot().setRootVersionImpl(version);
197 public final void addMutableStmtToSeal(final MutableStatement mutableStatement) {
198 getRoot().addMutableStmtToSealImpl(mutableStatement);
202 public final void addRequiredSource(final SourceIdentifier dependency) {
203 getRoot().addRequiredSourceImpl(dependency);
207 public final void setRootIdentifier(final SourceIdentifier identifier) {
208 getRoot().setRootIdentifierImpl(identifier);
212 public final boolean isEnabledSemanticVersioning() {
213 return getRoot().isEnabledSemanticVersioningImpl();
217 public final ModelActionBuilder newInferenceAction(final ModelProcessingPhase phase) {
218 return getRoot().getSourceContext().newInferenceAction(phase);
222 public final StatementDefinition publicDefinition() {
223 return definition().getPublicView();
227 public final Parent effectiveParent() {
228 return getParentContext();
232 public final CommonStmtCtx root() {
237 public final EffectiveStatement<?, ?> original() {
238 return getOriginalCtx().map(StmtContext::buildEffective).orElse(null);
243 @SuppressWarnings("unchecked")
244 public final <Z extends EffectiveStatement<A, D>> StmtContext<A, D, Z> caerbannog() {
245 return (StmtContext<A, D, Z>) this;
249 public final String toString() {
250 return addToStringAttributes(MoreObjects.toStringHelper(this).omitNullValues()).toString();
253 protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
254 return toStringHelper.add("definition", definition()).add("rawArgument", rawArgument());
258 * Return the context in which this statement was defined.
260 * @return statement definition
262 abstract @NonNull StatementDefinitionContext<A, D, E> definition();
266 // NamespaceStorageSupport/Mutable integration methods. Keep these together.
271 public final <K, V, T extends K, N extends IdentifierNamespace<K, V>> V namespaceItem(final Class<@NonNull N> type,
273 return getBehaviourRegistry().getNamespaceBehaviour(type).getFrom(this, key);
277 public final <K, V, N extends IdentifierNamespace<K, V>> Map<K, V> namespace(final Class<@NonNull N> type) {
278 return getNamespace(type);
282 public final <K, V, N extends IdentifierNamespace<K, V>> Map<K, V> localNamespace(final Class<@NonNull N> type) {
283 return getLocalNamespace(type);
287 protected final void checkLocalNamespaceAllowed(final Class<? extends IdentifierNamespace<?, ?>> type) {
288 definition().checkNamespaceAllowed(type);
292 protected <K, V, N extends IdentifierNamespace<K, V>> void onNamespaceElementAdded(final Class<N> type, final K key,
294 // definition().onNamespaceElementAdded(this, type, key, value);
299 // Statement build entry points -- both public and package-private.
304 public final E buildEffective() {
306 return (existing = effectiveInstance) != null ? existing : loadEffective();
309 private E loadEffective() {
310 // Creating an effective statement does not strictly require a declared instance -- there are statements like
311 // 'input', which are implicitly defined.
312 // Our implementation design makes an invariant assumption that buildDeclared() has been called by the time
313 // we attempt to create effective statement:
316 final E ret = effectiveInstance = createEffective();
317 // we have called createEffective(), substatements are no longer guarded by us. Let's see if we can clear up
319 if (refcount == REFCOUNT_NONE) {
325 abstract @NonNull E createEffective();
328 * Try to execute current {@link ModelProcessingPhase} of source parsing. If the phase has already been executed,
329 * this method does nothing.
331 * @param phase to be executed (completed)
332 * @return true if phase was successfully completed
333 * @throws SourceException when an error occurred in source parsing
335 final boolean tryToCompletePhase(final ModelProcessingPhase phase) {
336 return phase.isCompletedBy(getCompletedPhase()) || doTryToCompletePhase(phase);
339 abstract boolean doTryToCompletePhase(ModelProcessingPhase phase);
343 // Flags-based mechanics. These include public interfaces as well as all the crud we have lurking in our alignment
349 public final boolean isSupportedToBuildEffective() {
350 return isSupportedToBuildEffective;
354 public final void setIsSupportedToBuildEffective(final boolean isSupportedToBuildEffective) {
355 this.isSupportedToBuildEffective = isSupportedToBuildEffective;
359 public final boolean isSupportedByFeatures() {
360 final int fl = flags & SET_SUPPORTED_BY_FEATURES;
362 return fl == SET_SUPPORTED_BY_FEATURES;
364 if (isIgnoringIfFeatures()) {
365 flags |= SET_SUPPORTED_BY_FEATURES;
370 * If parent is supported, we need to check if-features statements of this context.
372 if (isParentSupportedByFeatures()) {
373 // If the set of supported features has not been provided, all features are supported by default.
374 final Set<QName> supportedFeatures = getFromNamespace(SupportedFeaturesNamespace.class,
375 SupportedFeatures.SUPPORTED_FEATURES);
376 if (supportedFeatures == null || StmtContextUtils.checkFeatureSupport(this, supportedFeatures)) {
377 flags |= SET_SUPPORTED_BY_FEATURES;
382 // Either parent is not supported or this statement is not supported
383 flags |= HAVE_SUPPORTED_BY_FEATURES;
387 protected abstract boolean isParentSupportedByFeatures();
390 * Config statements are not all that common which means we are performing a recursive search towards the root
391 * every time {@link #effectiveConfig()} is invoked. This is quite expensive because it causes a linear search
392 * for the (usually non-existent) config statement.
395 * This method maintains a resolution cache, so once we have returned a result, we will keep on returning the same
396 * result without performing any lookups, solely to support {@link #effectiveConfig()}.
399 * Note: use of this method implies that {@link #isIgnoringConfig()} is realized with
400 * {@link #isIgnoringConfig(StatementContextBase)}.
402 final @NonNull EffectiveConfig effectiveConfig(final ReactorStmtCtx<?, ?, ?> parent) {
403 return (flags & HAVE_CONFIG) != 0 ? EFFECTIVE_CONFIGS[flags & MASK_CONFIG] : loadEffectiveConfig(parent);
406 private @NonNull EffectiveConfig loadEffectiveConfig(final ReactorStmtCtx<?, ?, ?> parent) {
407 final EffectiveConfig parentConfig = parent.effectiveConfig();
409 final EffectiveConfig myConfig;
410 if (parentConfig != EffectiveConfig.IGNORED && !definition().support().isIgnoringConfig()) {
411 final Optional<Boolean> optConfig = findSubstatementArgument(ConfigEffectiveStatement.class);
412 if (optConfig.isPresent()) {
413 if (optConfig.orElseThrow()) {
414 // Validity check: if parent is config=false this cannot be a config=true
415 InferenceException.throwIf(parentConfig == EffectiveConfig.FALSE, this,
416 "Parent node has config=false, this node must not be specifed as config=true");
417 myConfig = EffectiveConfig.TRUE;
419 myConfig = EffectiveConfig.FALSE;
422 // If "config" statement is not specified, the default is the same as the parent's "config" value.
423 myConfig = parentConfig;
426 myConfig = EffectiveConfig.IGNORED;
429 flags = (byte) (flags & ~MASK_CONFIG | HAVE_CONFIG | myConfig.ordinal());
433 protected abstract boolean isIgnoringConfig();
436 * This method maintains a resolution cache for ignore config, so once we have returned a result, we will
437 * keep on returning the same result without performing any lookups. Exists only to support
438 * {@link SubstatementContext#isIgnoringConfig()}.
441 * Note: use of this method implies that {@link #isConfiguration()} is realized with
442 * {@link #effectiveConfig(StatementContextBase)}.
444 final boolean isIgnoringConfig(final StatementContextBase<?, ?, ?> parent) {
445 return EffectiveConfig.IGNORED == effectiveConfig(parent);
448 protected abstract boolean isIgnoringIfFeatures();
451 * This method maintains a resolution cache for ignore if-feature, so once we have returned a result, we will
452 * keep on returning the same result without performing any lookups. Exists only to support
453 * {@link SubstatementContext#isIgnoringIfFeatures()}.
455 final boolean isIgnoringIfFeatures(final StatementContextBase<?, ?, ?> parent) {
456 final int fl = flags & SET_IGNORE_IF_FEATURE;
458 return fl == SET_IGNORE_IF_FEATURE;
460 if (definition().support().isIgnoringIfFeatures() || parent.isIgnoringIfFeatures()) {
461 flags |= SET_IGNORE_IF_FEATURE;
465 flags |= HAVE_IGNORE_IF_FEATURE;
469 // These two exists only due to memory optimization, should live in AbstractResumedStatement. We are also reusing
470 // this for ReplicaStatementContext's refcount tracking.
471 final boolean fullyDefined() {
475 final void setFullyDefined() {
481 // Common SchemaPath cache. All of this is bound to be removed once YANGTOOLS-1066 is done.
485 // Exists only to support {SubstatementContext,InferredStatementContext}.schemaPath()
487 final @NonNull Optional<SchemaPath> substatementGetSchemaPath() {
488 SchemaPath local = schemaPath;
490 synchronized (this) {
493 schemaPath = local = createSchemaPath((StatementContextBase<?, ?, ?>) coerceParentContext());
498 return Optional.ofNullable(local);
502 private SchemaPath createSchemaPath(final StatementContextBase<?, ?, ?> parent) {
503 final Optional<SchemaPath> maybeParentPath = parent.schemaPath();
504 verify(maybeParentPath.isPresent(), "Parent %s does not have a SchemaPath", parent);
505 final SchemaPath parentPath = maybeParentPath.get();
507 if (StmtContextUtils.isUnknownStatement(this)) {
508 return parentPath.createChild(publicDefinition().getStatementName());
510 final Object argument = argument();
511 if (argument instanceof QName) {
512 final QName qname = (QName) argument;
513 if (producesDeclared(UsesStatement.class)) {
514 return maybeParentPath.orElse(null);
517 return parentPath.createChild(qname);
519 if (argument instanceof String) {
520 // FIXME: This may yield illegal argument exceptions
521 final Optional<StmtContext<A, D, E>> originalCtx = getOriginalCtx();
522 final QName qname = StmtContextUtils.qnameFromArgument(originalCtx.orElse(this), (String) argument);
523 return parentPath.createChild(qname);
525 if (argument instanceof SchemaNodeIdentifier
526 && (producesDeclared(AugmentStatement.class) || producesDeclared(RefineStatement.class)
527 || producesDeclared(DeviationStatement.class))) {
529 return parentPath.createChild(((SchemaNodeIdentifier) argument).getNodeIdentifiers());
532 // FIXME: this does not look right
533 return maybeParentPath.orElse(null);
538 // Reference counting mechanics start. Please keep these methods in one block for clarity. Note this does not
539 // contribute to state visible outside of this package.
544 * Local knowledge of {@link #refcount} values up to statement root. We use this field to prevent recursive lookups
545 * in {@link #noParentRefs(StatementContextBase)} -- once we discover a parent reference once, we keep that
546 * knowledge and update it when {@link #sweep()} is invoked.
548 private byte parentRef = PARENTREF_UNKNOWN;
549 private static final byte PARENTREF_UNKNOWN = -1;
550 private static final byte PARENTREF_ABSENT = 0;
551 private static final byte PARENTREF_PRESENT = 1;
554 * Acquire a reference on this context. As long as there is at least one reference outstanding,
555 * {@link #buildEffective()} will not result in {@link #effectiveSubstatements()} being discarded.
557 * @throws VerifyException if {@link #effectiveSubstatements()} has already been discarded
559 final void incRef() {
560 final int current = refcount;
561 verify(current >= REFCOUNT_NONE, "Attempted to access reference count of %s", this);
562 if (current != REFCOUNT_DEFUNCT) {
563 // Note: can end up becoming REFCOUNT_DEFUNCT on overflow
564 refcount = current + 1;
566 LOG.debug("Disabled refcount increment of {}", this);
571 * Release a reference on this context. This call may result in {@link #effectiveSubstatements()} becoming
574 final void decRef() {
575 final int current = refcount;
576 if (current == REFCOUNT_DEFUNCT) {
578 LOG.debug("Disabled refcount decrement of {}", this);
581 if (current <= REFCOUNT_NONE) {
582 // Underflow, become defunct
583 LOG.warn("Statement refcount underflow, reference counting disabled for {}", this, new Throwable());
584 refcount = REFCOUNT_DEFUNCT;
588 refcount = current - 1;
589 LOG.trace("Refcount {} on {}", refcount, this);
591 if (refcount == REFCOUNT_NONE) {
596 private void lastDecRef() {
597 if (noImplictRef()) {
598 // We are no longer guarded by effective instance
603 final byte prevRefs = parentRef;
604 if (prevRefs == PARENTREF_ABSENT) {
605 // We are the last reference towards root, any children who observed PARENTREF_PRESENT from us need to be
608 } else if (prevRefs == PARENTREF_UNKNOWN) {
609 // Noone observed our parentRef, just update it
610 loadParentRefcount();
614 static final void markNoParentRef(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
615 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
616 final byte prevRef = stmt.parentRef;
617 stmt.parentRef = PARENTREF_ABSENT;
618 if (prevRef == PARENTREF_PRESENT && stmt.refcount == REFCOUNT_NONE) {
619 // Child thinks it is pinned down, update its perspective
620 stmt.markNoParentRef();
625 abstract void markNoParentRef();
627 static final void sweep(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
628 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
634 * Sweep this statement context as a result of {@link #sweepSubstatements()}, i.e. when parent is also being swept.
636 private void sweep() {
637 parentRef = PARENTREF_ABSENT;
638 if (refcount == REFCOUNT_NONE && noImplictRef()) {
639 LOG.trace("Releasing {}", this);
644 static final int countUnswept(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
646 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
647 if (stmt.refcount > REFCOUNT_NONE || !stmt.noImplictRef()) {
655 * Implementation-specific sweep action. This is expected to perform a recursive {@link #sweep(Collection)} on all
656 * {@link #declaredSubstatements()} and {@link #effectiveSubstatements()} and report the result of the sweep
660 * {@link #effectiveSubstatements()} as well as namespaces may become inoperable as a result of this operation.
662 * @return True if the entire tree has been completely swept, false otherwise.
664 abstract int sweepSubstatements();
666 // Called when this statement does not have an implicit reference and have reached REFCOUNT_NONE
667 private void sweepOnDecrement() {
668 LOG.trace("Sweeping on decrement {}", this);
670 // No further parent references, sweep our state.
674 // Propagate towards parent if there is one
675 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
676 if (parent != null) {
677 parent.sweepOnChildDecrement();
681 // Called from child when it has lost its final reference
682 private void sweepOnChildDecrement() {
683 if (isAwaitingChildren()) {
684 // We are a child for which our parent is waiting. Notify it and we are done.
689 // Check parent reference count
690 final int refs = refcount;
691 if (refs > REFCOUNT_NONE || refs <= REFCOUNT_SWEEPING || !noImplictRef()) {
696 // parent is potentially reclaimable
698 LOG.trace("Cleanup {} of parent {}", refcount, this);
700 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
701 if (parent != null) {
702 parent.sweepOnChildDecrement();
708 private boolean noImplictRef() {
709 return effectiveInstance != null || !isSupportedToBuildEffective();
712 private boolean noParentRef() {
713 return parentRefcount() == PARENTREF_ABSENT;
716 private byte parentRefcount() {
718 return (refs = parentRef) != PARENTREF_UNKNOWN ? refs : loadParentRefcount();
721 private byte loadParentRefcount() {
722 return parentRef = calculateParentRefcount();
725 private byte calculateParentRefcount() {
726 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
727 if (parent == null) {
728 return PARENTREF_ABSENT;
730 // There are three possibilities:
731 // - REFCOUNT_NONE, in which case we need to search next parent
732 // - negative (< REFCOUNT_NONE), meaning parent is in some stage of sweeping, hence it does not have
734 // - positive (> REFCOUNT_NONE), meaning parent has an explicit refcount which is holding us down
735 final int refs = parent.refcount;
736 if (refs == REFCOUNT_NONE) {
737 return parent.parentRefcount();
739 return refs < REFCOUNT_NONE ? PARENTREF_ABSENT : PARENTREF_PRESENT;
742 private boolean isAwaitingChildren() {
743 return refcount > REFCOUNT_SWEEPING && refcount < REFCOUNT_NONE;
746 private void sweepOnChildDone() {
747 LOG.trace("Sweeping on child done {}", this);
748 final int current = refcount;
749 if (current >= REFCOUNT_NONE) {
750 // no-op, perhaps we want to handle some cases differently?
751 LOG.trace("Ignoring child sweep of {} for {}", this, current);
754 verify(current != REFCOUNT_SWEPT, "Attempt to sweep a child of swept %s", this);
756 refcount = current + 1;
757 LOG.trace("Child refcount {}", refcount);
758 if (refcount == REFCOUNT_NONE) {
760 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
761 LOG.trace("Propagating to parent {}", parent);
762 if (parent != null && parent.isAwaitingChildren()) {
763 parent.sweepOnChildDone();
768 private void sweepDone() {
769 LOG.trace("Sweep done for {}", this);
770 refcount = REFCOUNT_SWEPT;
774 private boolean sweepState() {
775 refcount = REFCOUNT_SWEEPING;
776 final int childRefs = sweepSubstatements();
777 if (childRefs == 0) {
781 if (childRefs < 0 || childRefs >= REFCOUNT_DEFUNCT) {
782 LOG.warn("Negative child refcount {} cannot be stored, reference counting disabled for {}", childRefs, this,
784 refcount = REFCOUNT_DEFUNCT;
786 LOG.trace("Still {} outstanding children of {}", childRefs, this);
787 refcount = -childRefs;