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.StatementDefinition;
27 import org.opendaylight.yangtools.yang.model.api.stmt.AugmentStatement;
28 import org.opendaylight.yangtools.yang.model.api.stmt.ConfigEffectiveStatement;
29 import org.opendaylight.yangtools.yang.model.api.stmt.DeviationStatement;
30 import org.opendaylight.yangtools.yang.model.api.stmt.RefineStatement;
31 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier;
32 import org.opendaylight.yangtools.yang.model.api.stmt.UsesStatement;
33 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
34 import org.opendaylight.yangtools.yang.parser.spi.meta.EffectiveStmtCtx.Current;
35 import org.opendaylight.yangtools.yang.parser.spi.meta.InferenceException;
36 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelActionBuilder;
37 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelProcessingPhase;
38 import org.opendaylight.yangtools.yang.parser.spi.meta.NamespaceBehaviour.Registry;
39 import org.opendaylight.yangtools.yang.parser.spi.meta.ParserNamespace;
40 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext;
41 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext.Mutable;
42 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContextUtils;
43 import org.opendaylight.yangtools.yang.parser.spi.source.SourceException;
44 import org.opendaylight.yangtools.yang.parser.spi.source.SupportedFeaturesNamespace;
45 import org.opendaylight.yangtools.yang.parser.spi.source.SupportedFeaturesNamespace.SupportedFeatures;
46 import org.slf4j.Logger;
47 import org.slf4j.LoggerFactory;
50 * Real "core" reactor statement implementation of {@link Mutable}, supporting basic reactor lifecycle.
52 * @param <A> Argument type
53 * @param <D> Declared Statement representation
54 * @param <E> Effective Statement representation
56 abstract class ReactorStmtCtx<A, D extends DeclaredStatement<A>, E extends EffectiveStatement<A, D>>
57 extends NamespaceStorageSupport implements Mutable<A, D, E>, Current<A, D> {
58 private static final Logger LOG = LoggerFactory.getLogger(ReactorStmtCtx.class);
61 * Substatement refcount tracking. This mechanics deals with retaining substatements for the purposes of
62 * instantiating their lazy copies in InferredStatementContext. It works in concert with {@link #buildEffective()}
63 * and {@link #declared()}: declared/effective statement views hold an implicit reference and refcount-based
64 * sweep is not activated until they are done (or this statement is not {@link #isSupportedToBuildEffective}).
67 * Reference count is hierarchical in that parent references also pin down their child statements and do not allow
71 * The counter's positive values are tracking incoming references via {@link #incRef()}/{@link #decRef()} methods.
72 * Once we transition to sweeping, this value becomes negative counting upwards to {@link #REFCOUNT_NONE} based on
73 * {@link #sweepOnChildDone()}. Once we reach that, we transition to {@link #REFCOUNT_SWEPT}.
75 private int refcount = REFCOUNT_NONE;
77 * No outstanding references, this statement is a potential candidate for sweeping, provided it has populated its
78 * declared and effective views and {@link #parentRef} is known to be absent.
80 private static final int REFCOUNT_NONE = 0;
82 * Reference count overflow or some other recoverable logic error. Do not rely on refcounts and do not sweep
86 * Note on value assignment:
87 * This allow our incRef() to naturally progress to being saturated. Others jump there directly.
88 * It also makes it it impossible to observe {@code Interger.MAX_VALUE} children, which we take advantage of for
89 * {@link #REFCOUNT_SWEEPING}.
91 private static final int REFCOUNT_DEFUNCT = Integer.MAX_VALUE;
93 * This statement is being actively swept. This is a transient value set when we are sweeping our children, so that
94 * we prevent re-entering this statement.
97 * Note on value assignment:
98 * The value is lower than any legal child refcount due to {@link #REFCOUNT_DEFUNCT} while still being higher than
99 * {@link #REFCOUNT_SWEPT}.
101 private static final int REFCOUNT_SWEEPING = -Integer.MAX_VALUE;
103 * This statement, along with its entire subtree has been swept and we positively know all our children have reached
104 * this state. We {@link #sweepNamespaces()} upon reaching this state.
107 * Note on value assignment:
108 * This is the lowest value observable, making it easier on checking others on equality.
110 private static final int REFCOUNT_SWEPT = Integer.MIN_VALUE;
112 private @Nullable E effectiveInstance;
114 // Master flag controlling whether this context can yield an effective statement
115 // FIXME: investigate the mechanics that are being supported by this, as it would be beneficial if we can get rid
116 // of this flag -- eliminating the initial alignment shadow used by below gap-filler fields.
117 private boolean isSupportedToBuildEffective = true;
119 // Flag bit assignments
120 private static final int IS_SUPPORTED_BY_FEATURES = 0x10;
121 private static final int HAVE_SUPPORTED_BY_FEATURES = 0x20;
122 private static final int IS_IGNORE_IF_FEATURE = 0x40;
123 private static final int HAVE_IGNORE_IF_FEATURE = 0x80;
124 // Have-and-set flag constants, also used as masks
125 private static final int SET_SUPPORTED_BY_FEATURES = HAVE_SUPPORTED_BY_FEATURES | IS_SUPPORTED_BY_FEATURES;
126 private static final int SET_IGNORE_IF_FEATURE = HAVE_IGNORE_IF_FEATURE | IS_IGNORE_IF_FEATURE;
128 // EffectiveConfig mapping
129 private static final int MASK_CONFIG = 0x03;
130 private static final int HAVE_CONFIG = 0x04;
131 private static final EffectiveConfig[] EFFECTIVE_CONFIGS;
134 final EffectiveConfig[] values = EffectiveConfig.values();
135 final int length = values.length;
136 verify(length == 4, "Unexpected EffectiveConfig cardinality %s", length);
137 EFFECTIVE_CONFIGS = values;
140 // Flags for use with SubstatementContext. These are hiding in the alignment shadow created by above boolean and
141 // hence improve memory layout.
144 // Flag for use with AbstractResumedStatement. This is hiding in the alignment shadow created by above boolean
145 // FIXME: move this out once we have JDK15+
146 private boolean fullyDefined;
148 // SchemaPath cache for use with SubstatementContext and InferredStatementContext. This hurts RootStatementContext
149 // a bit in terms of size -- but those are only a few and SchemaPath is on its way out anyway.
151 private volatile SchemaPath schemaPath;
157 ReactorStmtCtx(final ReactorStmtCtx<A, D, E> original) {
158 isSupportedToBuildEffective = original.isSupportedToBuildEffective;
159 fullyDefined = original.fullyDefined;
160 flags = original.flags;
165 // Common public interface contracts with simple mechanics. Please keep this in one logical block, so we do not end
166 // up mixing concerns and simple details with more complex logic.
171 public abstract StatementContextBase<?, ?, ?> getParentContext();
174 public abstract RootStatementContext<?, ?, ?> getRoot();
177 public abstract Collection<? extends StatementContextBase<?, ?, ?>> mutableDeclaredSubstatements();
180 public final @NonNull Registry getBehaviourRegistry() {
181 return getRoot().getBehaviourRegistryImpl();
185 public final YangVersion yangVersion() {
186 return getRoot().getRootVersionImpl();
190 public final void setRootVersion(final YangVersion version) {
191 getRoot().setRootVersionImpl(version);
195 public final void addRequiredSource(final SourceIdentifier dependency) {
196 getRoot().addRequiredSourceImpl(dependency);
200 public final void setRootIdentifier(final SourceIdentifier identifier) {
201 getRoot().setRootIdentifierImpl(identifier);
205 public final boolean isEnabledSemanticVersioning() {
206 return getRoot().isEnabledSemanticVersioningImpl();
210 public final ModelActionBuilder newInferenceAction(final ModelProcessingPhase phase) {
211 return getRoot().getSourceContext().newInferenceAction(phase);
215 public final StatementDefinition publicDefinition() {
216 return definition().getPublicView();
220 public final Parent effectiveParent() {
221 return getParentContext();
225 public final QName moduleName() {
226 final RootStatementContext<?, ?, ?> root = getRoot();
227 return QName.create(StmtContextUtils.getRootModuleQName(root), root.getRawArgument());
231 public final EffectiveStatement<?, ?> original() {
232 return getOriginalCtx().map(StmtContext::buildEffective).orElse(null);
236 // Non-final due to InferredStatementContext's override
237 public <X, Z extends EffectiveStatement<X, ?>> @NonNull Optional<X> findSubstatementArgument(
238 final @NonNull Class<Z> type) {
239 return allSubstatementsStream()
240 .filter(ctx -> ctx.isSupportedToBuildEffective() && ctx.producesEffective(type))
242 .map(ctx -> (X) ctx.getArgument());
246 // Non-final due to InferredStatementContext's override
247 public boolean hasSubstatement(final @NonNull Class<? extends EffectiveStatement<?, ?>> type) {
248 return allSubstatementsStream()
249 .anyMatch(ctx -> ctx.isSupportedToBuildEffective() && ctx.producesEffective(type));
254 @SuppressWarnings("unchecked")
255 public final <Z extends EffectiveStatement<A, D>> StmtContext<A, D, Z> caerbannog() {
256 return (StmtContext<A, D, Z>) this;
260 public final String toString() {
261 return addToStringAttributes(MoreObjects.toStringHelper(this).omitNullValues()).toString();
264 protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
265 return toStringHelper.add("definition", definition()).add("rawArgument", rawArgument());
269 * Return the context in which this statement was defined.
271 * @return statement definition
273 abstract @NonNull StatementDefinitionContext<A, D, E> definition();
277 // NamespaceStorageSupport/Mutable integration methods. Keep these together.
282 public final <K, V, T extends K, N extends ParserNamespace<K, V>> V namespaceItem(final Class<@NonNull N> type,
284 return getBehaviourRegistry().getNamespaceBehaviour(type).getFrom(this, key);
288 public final <K, V, N extends ParserNamespace<K, V>> Map<K, V> namespace(final Class<@NonNull N> type) {
289 return getNamespace(type);
293 public final <K, V, N extends ParserNamespace<K, V>>
294 Map<K, V> localNamespacePortion(final Class<@NonNull N> type) {
295 return getLocalNamespace(type);
299 protected final void checkLocalNamespaceAllowed(final Class<? extends ParserNamespace<?, ?>> type) {
300 definition().checkNamespaceAllowed(type);
304 protected <K, V, N extends ParserNamespace<K, V>> void onNamespaceElementAdded(final Class<N> type, final K key,
306 // definition().onNamespaceElementAdded(this, type, key, value);
311 // Statement build entry points -- both public and package-private.
316 public final E buildEffective() {
318 return (existing = effectiveInstance) != null ? existing : loadEffective();
321 private E loadEffective() {
322 // Creating an effective statement does not strictly require a declared instance -- there are statements like
323 // 'input', which are implicitly defined.
324 // Our implementation design makes an invariant assumption that buildDeclared() has been called by the time
325 // we attempt to create effective statement:
328 final E ret = effectiveInstance = createEffective();
329 // we have called createEffective(), substatements are no longer guarded by us. Let's see if we can clear up
331 if (refcount == REFCOUNT_NONE) {
337 abstract @NonNull E createEffective();
340 * Try to execute current {@link ModelProcessingPhase} of source parsing. If the phase has already been executed,
341 * this method does nothing.
343 * @param phase to be executed (completed)
344 * @return true if phase was successfully completed
345 * @throws SourceException when an error occurred in source parsing
347 final boolean tryToCompletePhase(final ModelProcessingPhase phase) {
348 return phase.isCompletedBy(getCompletedPhase()) || doTryToCompletePhase(phase);
351 abstract boolean doTryToCompletePhase(ModelProcessingPhase phase);
355 // Flags-based mechanics. These include public interfaces as well as all the crud we have lurking in our alignment
361 public final boolean isSupportedToBuildEffective() {
362 return isSupportedToBuildEffective;
366 public final void setIsSupportedToBuildEffective(final boolean isSupportedToBuildEffective) {
367 this.isSupportedToBuildEffective = isSupportedToBuildEffective;
371 public final boolean isSupportedByFeatures() {
372 final int fl = flags & SET_SUPPORTED_BY_FEATURES;
374 return fl == SET_SUPPORTED_BY_FEATURES;
376 if (isIgnoringIfFeatures()) {
377 flags |= SET_SUPPORTED_BY_FEATURES;
382 * If parent is supported, we need to check if-features statements of this context.
384 if (isParentSupportedByFeatures()) {
385 // If the set of supported features has not been provided, all features are supported by default.
386 final Set<QName> supportedFeatures = getFromNamespace(SupportedFeaturesNamespace.class,
387 SupportedFeatures.SUPPORTED_FEATURES);
388 if (supportedFeatures == null || StmtContextUtils.checkFeatureSupport(this, supportedFeatures)) {
389 flags |= SET_SUPPORTED_BY_FEATURES;
394 // Either parent is not supported or this statement is not supported
395 flags |= HAVE_SUPPORTED_BY_FEATURES;
399 protected abstract boolean isParentSupportedByFeatures();
402 * Config statements are not all that common which means we are performing a recursive search towards the root
403 * every time {@link #effectiveConfig()} is invoked. This is quite expensive because it causes a linear search
404 * for the (usually non-existent) config statement.
407 * This method maintains a resolution cache, so once we have returned a result, we will keep on returning the same
408 * result without performing any lookups, solely to support {@link #effectiveConfig()}.
411 * Note: use of this method implies that {@link #isIgnoringConfig()} is realized with
412 * {@link #isIgnoringConfig(StatementContextBase)}.
414 final @NonNull EffectiveConfig effectiveConfig(final ReactorStmtCtx<?, ?, ?> parent) {
415 return (flags & HAVE_CONFIG) != 0 ? EFFECTIVE_CONFIGS[flags & MASK_CONFIG] : loadEffectiveConfig(parent);
418 private @NonNull EffectiveConfig loadEffectiveConfig(final ReactorStmtCtx<?, ?, ?> parent) {
419 final EffectiveConfig parentConfig = parent.effectiveConfig();
421 final EffectiveConfig myConfig;
422 if (parentConfig != EffectiveConfig.IGNORED && !definition().support().isIgnoringConfig()) {
423 final Optional<Boolean> optConfig = findSubstatementArgument(ConfigEffectiveStatement.class);
424 if (optConfig.isPresent()) {
425 if (optConfig.orElseThrow()) {
426 // Validity check: if parent is config=false this cannot be a config=true
427 InferenceException.throwIf(parentConfig == EffectiveConfig.FALSE, this,
428 "Parent node has config=false, this node must not be specifed as config=true");
429 myConfig = EffectiveConfig.TRUE;
431 myConfig = EffectiveConfig.FALSE;
434 // If "config" statement is not specified, the default is the same as the parent's "config" value.
435 myConfig = parentConfig;
438 myConfig = EffectiveConfig.IGNORED;
441 flags = (byte) (flags & ~MASK_CONFIG | HAVE_CONFIG | myConfig.ordinal());
445 protected abstract boolean isIgnoringConfig();
448 * This method maintains a resolution cache for ignore config, so once we have returned a result, we will
449 * keep on returning the same result without performing any lookups. Exists only to support
450 * {@link SubstatementContext#isIgnoringConfig()}.
453 * Note: use of this method implies that {@link #isConfiguration()} is realized with
454 * {@link #effectiveConfig(StatementContextBase)}.
456 final boolean isIgnoringConfig(final StatementContextBase<?, ?, ?> parent) {
457 return EffectiveConfig.IGNORED == effectiveConfig(parent);
460 protected abstract boolean isIgnoringIfFeatures();
463 * This method maintains a resolution cache for ignore if-feature, so once we have returned a result, we will
464 * keep on returning the same result without performing any lookups. Exists only to support
465 * {@link SubstatementContext#isIgnoringIfFeatures()}.
467 final boolean isIgnoringIfFeatures(final StatementContextBase<?, ?, ?> parent) {
468 final int fl = flags & SET_IGNORE_IF_FEATURE;
470 return fl == SET_IGNORE_IF_FEATURE;
472 if (definition().support().isIgnoringIfFeatures() || parent.isIgnoringIfFeatures()) {
473 flags |= SET_IGNORE_IF_FEATURE;
477 flags |= HAVE_IGNORE_IF_FEATURE;
481 // These two exists only due to memory optimization, should live in AbstractResumedStatement. We are also reusing
482 // this for ReplicaStatementContext's refcount tracking.
483 final boolean fullyDefined() {
487 final void setFullyDefined() {
493 // Common SchemaPath cache. All of this is bound to be removed once YANGTOOLS-1066 is done.
497 // Exists only to support {SubstatementContext,InferredStatementContext}.schemaPath()
499 final @NonNull Optional<SchemaPath> substatementGetSchemaPath() {
500 SchemaPath local = schemaPath;
502 synchronized (this) {
505 schemaPath = local = createSchemaPath((StatementContextBase<?, ?, ?>) coerceParentContext());
510 return Optional.ofNullable(local);
514 private SchemaPath createSchemaPath(final StatementContextBase<?, ?, ?> parent) {
515 final Optional<SchemaPath> maybeParentPath = parent.schemaPath();
516 verify(maybeParentPath.isPresent(), "Parent %s does not have a SchemaPath", parent);
517 final SchemaPath parentPath = maybeParentPath.get();
519 if (StmtContextUtils.isUnknownStatement(this)) {
520 return parentPath.createChild(publicDefinition().getStatementName());
522 final Object argument = argument();
523 if (argument instanceof QName) {
524 final QName qname = (QName) argument;
525 if (producesDeclared(UsesStatement.class)) {
526 return maybeParentPath.orElse(null);
529 return parentPath.createChild(qname);
531 if (argument instanceof String) {
532 // FIXME: This may yield illegal argument exceptions
533 final Optional<StmtContext<A, D, E>> originalCtx = getOriginalCtx();
534 final QName qname = StmtContextUtils.qnameFromArgument(originalCtx.orElse(this), (String) argument);
535 return parentPath.createChild(qname);
537 if (argument instanceof SchemaNodeIdentifier
538 && (producesDeclared(AugmentStatement.class) || producesDeclared(RefineStatement.class)
539 || producesDeclared(DeviationStatement.class))) {
541 return parentPath.createChild(((SchemaNodeIdentifier) argument).getNodeIdentifiers());
544 // FIXME: this does not look right
545 return maybeParentPath.orElse(null);
550 // Reference counting mechanics start. Please keep these methods in one block for clarity. Note this does not
551 // contribute to state visible outside of this package.
556 * Local knowledge of {@link #refcount} values up to statement root. We use this field to prevent recursive lookups
557 * in {@link #noParentRefs(StatementContextBase)} -- once we discover a parent reference once, we keep that
558 * knowledge and update it when {@link #sweep()} is invoked.
560 private byte parentRef = PARENTREF_UNKNOWN;
561 private static final byte PARENTREF_UNKNOWN = -1;
562 private static final byte PARENTREF_ABSENT = 0;
563 private static final byte PARENTREF_PRESENT = 1;
566 * Acquire a reference on this context. As long as there is at least one reference outstanding,
567 * {@link #buildEffective()} will not result in {@link #effectiveSubstatements()} being discarded.
569 * @throws VerifyException if {@link #effectiveSubstatements()} has already been discarded
571 final void incRef() {
572 final int current = refcount;
573 verify(current >= REFCOUNT_NONE, "Attempted to access reference count of %s", this);
574 if (current != REFCOUNT_DEFUNCT) {
575 // Note: can end up becoming REFCOUNT_DEFUNCT on overflow
576 refcount = current + 1;
578 LOG.debug("Disabled refcount increment of {}", this);
583 * Release a reference on this context. This call may result in {@link #effectiveSubstatements()} becoming
586 final void decRef() {
587 final int current = refcount;
588 if (current == REFCOUNT_DEFUNCT) {
590 LOG.debug("Disabled refcount decrement of {}", this);
593 if (current <= REFCOUNT_NONE) {
594 // Underflow, become defunct
595 LOG.warn("Statement refcount underflow, reference counting disabled for {}", this, new Throwable());
596 refcount = REFCOUNT_DEFUNCT;
600 refcount = current - 1;
601 LOG.trace("Refcount {} on {}", refcount, this);
603 if (refcount == REFCOUNT_NONE) {
608 private void lastDecRef() {
609 if (noImplictRef()) {
610 // We are no longer guarded by effective instance
615 final byte prevRefs = parentRef;
616 if (prevRefs == PARENTREF_ABSENT) {
617 // We are the last reference towards root, any children who observed PARENTREF_PRESENT from us need to be
620 } else if (prevRefs == PARENTREF_UNKNOWN) {
621 // Noone observed our parentRef, just update it
622 loadParentRefcount();
626 static final void markNoParentRef(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
627 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
628 final byte prevRef = stmt.parentRef;
629 stmt.parentRef = PARENTREF_ABSENT;
630 if (prevRef == PARENTREF_PRESENT && stmt.refcount == REFCOUNT_NONE) {
631 // Child thinks it is pinned down, update its perspective
632 stmt.markNoParentRef();
637 abstract void markNoParentRef();
639 static final void sweep(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
640 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
646 * Sweep this statement context as a result of {@link #sweepSubstatements()}, i.e. when parent is also being swept.
648 private void sweep() {
649 parentRef = PARENTREF_ABSENT;
650 if (refcount == REFCOUNT_NONE && noImplictRef()) {
651 LOG.trace("Releasing {}", this);
656 static final int countUnswept(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
658 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
659 if (stmt.refcount > REFCOUNT_NONE || !stmt.noImplictRef()) {
667 * Implementation-specific sweep action. This is expected to perform a recursive {@link #sweep(Collection)} on all
668 * {@link #declaredSubstatements()} and {@link #effectiveSubstatements()} and report the result of the sweep
672 * {@link #effectiveSubstatements()} as well as namespaces may become inoperable as a result of this operation.
674 * @return True if the entire tree has been completely swept, false otherwise.
676 abstract int sweepSubstatements();
678 // Called when this statement does not have an implicit reference and have reached REFCOUNT_NONE
679 private void sweepOnDecrement() {
680 LOG.trace("Sweeping on decrement {}", this);
682 // No further parent references, sweep our state.
686 // Propagate towards parent if there is one
687 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
688 if (parent != null) {
689 parent.sweepOnChildDecrement();
693 // Called from child when it has lost its final reference
694 private void sweepOnChildDecrement() {
695 if (isAwaitingChildren()) {
696 // We are a child for which our parent is waiting. Notify it and we are done.
701 // Check parent reference count
702 final int refs = refcount;
703 if (refs > REFCOUNT_NONE || refs <= REFCOUNT_SWEEPING || !noImplictRef()) {
708 // parent is potentially reclaimable
710 LOG.trace("Cleanup {} of parent {}", refcount, this);
712 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
713 if (parent != null) {
714 parent.sweepOnChildDecrement();
720 private boolean noImplictRef() {
721 return effectiveInstance != null || !isSupportedToBuildEffective();
724 private boolean noParentRef() {
725 return parentRefcount() == PARENTREF_ABSENT;
728 private byte parentRefcount() {
730 return (refs = parentRef) != PARENTREF_UNKNOWN ? refs : loadParentRefcount();
733 private byte loadParentRefcount() {
734 return parentRef = calculateParentRefcount();
737 private byte calculateParentRefcount() {
738 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
739 if (parent == null) {
740 return PARENTREF_ABSENT;
742 // There are three possibilities:
743 // - REFCOUNT_NONE, in which case we need to search next parent
744 // - negative (< REFCOUNT_NONE), meaning parent is in some stage of sweeping, hence it does not have
746 // - positive (> REFCOUNT_NONE), meaning parent has an explicit refcount which is holding us down
747 final int refs = parent.refcount;
748 if (refs == REFCOUNT_NONE) {
749 return parent.parentRefcount();
751 return refs < REFCOUNT_NONE ? PARENTREF_ABSENT : PARENTREF_PRESENT;
754 private boolean isAwaitingChildren() {
755 return refcount > REFCOUNT_SWEEPING && refcount < REFCOUNT_NONE;
758 private void sweepOnChildDone() {
759 LOG.trace("Sweeping on child done {}", this);
760 final int current = refcount;
761 if (current >= REFCOUNT_NONE) {
762 // no-op, perhaps we want to handle some cases differently?
763 LOG.trace("Ignoring child sweep of {} for {}", this, current);
766 verify(current != REFCOUNT_SWEPT, "Attempt to sweep a child of swept %s", this);
768 refcount = current + 1;
769 LOG.trace("Child refcount {}", refcount);
770 if (refcount == REFCOUNT_NONE) {
772 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
773 LOG.trace("Propagating to parent {}", parent);
774 if (parent != null && parent.isAwaitingChildren()) {
775 parent.sweepOnChildDone();
780 private void sweepDone() {
781 LOG.trace("Sweep done for {}", this);
782 refcount = REFCOUNT_SWEPT;
786 private boolean sweepState() {
787 refcount = REFCOUNT_SWEEPING;
788 final int childRefs = sweepSubstatements();
789 if (childRefs == 0) {
793 if (childRefs < 0 || childRefs >= REFCOUNT_DEFUNCT) {
794 LOG.warn("Negative child refcount {} cannot be stored, reference counting disabled for {}", childRefs, this,
796 refcount = REFCOUNT_DEFUNCT;
798 LOG.trace("Still {} outstanding children of {}", childRefs, this);
799 refcount = -childRefs;