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.QNameModule;
23 import org.opendaylight.yangtools.yang.common.YangVersion;
24 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
25 import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
26 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
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.CopyType;
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.NamespaceBehaviour.Registry;
41 import org.opendaylight.yangtools.yang.parser.spi.meta.ParserNamespace;
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 // EffectiveConfig mapping
122 private static final int MASK_CONFIG = 0x03;
123 private static final int HAVE_CONFIG = 0x04;
124 // Effective instantiation mechanics for StatementContextBase: if this flag is set all substatements are known not
125 // change when instantiated. This includes context-independent statements as well as any statements which are
126 // ignored during copy instantiation.
127 private static final int ALL_INDEPENDENT = 0x08;
128 // Flag bit assignments
129 private static final int IS_SUPPORTED_BY_FEATURES = 0x10;
130 private static final int HAVE_SUPPORTED_BY_FEATURES = 0x20;
131 private static final int IS_IGNORE_IF_FEATURE = 0x40;
132 private static final int HAVE_IGNORE_IF_FEATURE = 0x80;
133 // Have-and-set flag constants, also used as masks
134 private static final int SET_SUPPORTED_BY_FEATURES = HAVE_SUPPORTED_BY_FEATURES | IS_SUPPORTED_BY_FEATURES;
135 private static final int SET_IGNORE_IF_FEATURE = HAVE_IGNORE_IF_FEATURE | IS_IGNORE_IF_FEATURE;
137 private static final EffectiveConfig[] EFFECTIVE_CONFIGS;
140 final EffectiveConfig[] values = EffectiveConfig.values();
141 final int length = values.length;
142 verify(length == 4, "Unexpected EffectiveConfig cardinality %s", length);
143 EFFECTIVE_CONFIGS = values;
146 // Flags for use with SubstatementContext. These are hiding in the alignment shadow created by above boolean and
147 // hence improve memory layout.
150 // Flag for use with AbstractResumedStatement. This is hiding in the alignment shadow created by above boolean
151 // FIXME: move this out once we have JDK15+
152 private boolean fullyDefined;
154 // SchemaPath cache for use with SubstatementContext and InferredStatementContext. This hurts RootStatementContext
155 // a bit in terms of size -- but those are only a few and SchemaPath is on its way out anyway.
157 private volatile SchemaPath schemaPath;
163 ReactorStmtCtx(final ReactorStmtCtx<A, D, E> original) {
164 isSupportedToBuildEffective = original.isSupportedToBuildEffective;
165 fullyDefined = original.fullyDefined;
166 flags = original.flags;
171 // Common public interface contracts with simple mechanics. Please keep this in one logical block, so we do not end
172 // up mixing concerns and simple details with more complex logic.
177 public abstract StatementContextBase<?, ?, ?> getParentContext();
180 public abstract RootStatementContext<?, ?, ?> getRoot();
183 public abstract Collection<? extends StatementContextBase<?, ?, ?>> mutableDeclaredSubstatements();
186 public final @NonNull Registry getBehaviourRegistry() {
187 return getRoot().getBehaviourRegistryImpl();
191 public final YangVersion yangVersion() {
192 return getRoot().getRootVersionImpl();
196 public final void setRootVersion(final YangVersion version) {
197 getRoot().setRootVersionImpl(version);
201 public final void addRequiredSource(final SourceIdentifier dependency) {
202 getRoot().addRequiredSourceImpl(dependency);
206 public final void setRootIdentifier(final SourceIdentifier identifier) {
207 getRoot().setRootIdentifierImpl(identifier);
211 public final boolean isEnabledSemanticVersioning() {
212 return getRoot().isEnabledSemanticVersioningImpl();
216 public final ModelActionBuilder newInferenceAction(final ModelProcessingPhase phase) {
217 return getRoot().getSourceContext().newInferenceAction(phase);
221 public final StatementDefinition publicDefinition() {
222 return definition().getPublicView();
226 public final Parent effectiveParent() {
227 return getParentContext();
231 public final QName moduleName() {
232 final RootStatementContext<?, ?, ?> root = getRoot();
233 return QName.create(StmtContextUtils.getRootModuleQName(root), root.getRawArgument());
237 public final EffectiveStatement<?, ?> original() {
238 return getOriginalCtx().map(StmtContext::buildEffective).orElse(null);
242 // Non-final due to InferredStatementContext's override
243 public <X, Z extends EffectiveStatement<X, ?>> @NonNull Optional<X> findSubstatementArgument(
244 final @NonNull Class<Z> type) {
245 return allSubstatementsStream()
246 .filter(ctx -> ctx.isSupportedToBuildEffective() && ctx.producesEffective(type))
248 .map(ctx -> (X) ctx.getArgument());
252 // Non-final due to InferredStatementContext's override
253 public boolean hasSubstatement(final @NonNull Class<? extends EffectiveStatement<?, ?>> type) {
254 return allSubstatementsStream()
255 .anyMatch(ctx -> ctx.isSupportedToBuildEffective() && ctx.producesEffective(type));
260 @SuppressWarnings("unchecked")
261 public final <Z extends EffectiveStatement<A, D>> StmtContext<A, D, Z> caerbannog() {
262 return (StmtContext<A, D, Z>) this;
266 public final String toString() {
267 return addToStringAttributes(MoreObjects.toStringHelper(this).omitNullValues()).toString();
270 protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
271 return toStringHelper.add("definition", definition()).add("rawArgument", rawArgument());
275 * Return the context in which this statement was defined.
277 * @return statement definition
279 abstract @NonNull StatementDefinitionContext<A, D, E> definition();
283 // NamespaceStorageSupport/Mutable integration methods. Keep these together.
288 public final <K, V, T extends K, N extends ParserNamespace<K, V>> V namespaceItem(final Class<@NonNull N> type,
290 return getBehaviourRegistry().getNamespaceBehaviour(type).getFrom(this, key);
294 public final <K, V, N extends ParserNamespace<K, V>> Map<K, V> namespace(final Class<@NonNull N> type) {
295 return getNamespace(type);
299 public final <K, V, N extends ParserNamespace<K, V>>
300 Map<K, V> localNamespacePortion(final Class<@NonNull N> type) {
301 return getLocalNamespace(type);
305 protected final void checkLocalNamespaceAllowed(final Class<? extends ParserNamespace<?, ?>> type) {
306 definition().checkNamespaceAllowed(type);
310 protected <K, V, N extends ParserNamespace<K, V>> void onNamespaceElementAdded(final Class<N> type, final K key,
312 // definition().onNamespaceElementAdded(this, type, key, value);
315 abstract @Nullable ReactorStmtCtx<?, ?, ?> asEffectiveChildOf(StatementContextBase<?, ?, ?> parent, CopyType type,
316 QNameModule targetModule);
320 // Statement build entry points -- both public and package-private.
325 public final E buildEffective() {
327 return (existing = effectiveInstance) != null ? existing : loadEffective();
330 private E loadEffective() {
331 // Creating an effective statement does not strictly require a declared instance -- there are statements like
332 // 'input', which are implicitly defined.
333 // Our implementation design makes an invariant assumption that buildDeclared() has been called by the time
334 // we attempt to create effective statement:
337 final E ret = effectiveInstance = createEffective();
338 // we have called createEffective(), substatements are no longer guarded by us. Let's see if we can clear up
340 if (refcount == REFCOUNT_NONE) {
346 abstract @NonNull E createEffective();
349 * Try to execute current {@link ModelProcessingPhase} of source parsing. If the phase has already been executed,
350 * this method does nothing.
352 * @param phase to be executed (completed)
353 * @return true if phase was successfully completed
354 * @throws SourceException when an error occurred in source parsing
356 final boolean tryToCompletePhase(final ModelProcessingPhase phase) {
357 return phase.isCompletedBy(getCompletedPhase()) || doTryToCompletePhase(phase);
360 abstract boolean doTryToCompletePhase(ModelProcessingPhase phase);
364 // Flags-based mechanics. These include public interfaces as well as all the crud we have lurking in our alignment
370 public final boolean isSupportedToBuildEffective() {
371 return isSupportedToBuildEffective;
375 public final void setIsSupportedToBuildEffective(final boolean isSupportedToBuildEffective) {
376 this.isSupportedToBuildEffective = isSupportedToBuildEffective;
380 public final boolean isSupportedByFeatures() {
381 final int fl = flags & SET_SUPPORTED_BY_FEATURES;
383 return fl == SET_SUPPORTED_BY_FEATURES;
385 if (isIgnoringIfFeatures()) {
386 flags |= SET_SUPPORTED_BY_FEATURES;
391 * If parent is supported, we need to check if-features statements of this context.
393 if (isParentSupportedByFeatures()) {
394 // If the set of supported features has not been provided, all features are supported by default.
395 final Set<QName> supportedFeatures = getFromNamespace(SupportedFeaturesNamespace.class,
396 SupportedFeatures.SUPPORTED_FEATURES);
397 if (supportedFeatures == null || StmtContextUtils.checkFeatureSupport(this, supportedFeatures)) {
398 flags |= SET_SUPPORTED_BY_FEATURES;
403 // Either parent is not supported or this statement is not supported
404 flags |= HAVE_SUPPORTED_BY_FEATURES;
408 protected abstract boolean isParentSupportedByFeatures();
411 * Config statements are not all that common which means we are performing a recursive search towards the root
412 * every time {@link #effectiveConfig()} is invoked. This is quite expensive because it causes a linear search
413 * for the (usually non-existent) config statement.
416 * This method maintains a resolution cache, so once we have returned a result, we will keep on returning the same
417 * result without performing any lookups, solely to support {@link #effectiveConfig()}.
420 * Note: use of this method implies that {@link #isIgnoringConfig()} is realized with
421 * {@link #isIgnoringConfig(StatementContextBase)}.
423 final @NonNull EffectiveConfig effectiveConfig(final ReactorStmtCtx<?, ?, ?> parent) {
424 return (flags & HAVE_CONFIG) != 0 ? EFFECTIVE_CONFIGS[flags & MASK_CONFIG] : loadEffectiveConfig(parent);
427 private @NonNull EffectiveConfig loadEffectiveConfig(final ReactorStmtCtx<?, ?, ?> parent) {
428 final EffectiveConfig parentConfig = parent.effectiveConfig();
430 final EffectiveConfig myConfig;
431 if (parentConfig != EffectiveConfig.IGNORED && !definition().support().isIgnoringConfig()) {
432 final Optional<Boolean> optConfig = findSubstatementArgument(ConfigEffectiveStatement.class);
433 if (optConfig.isPresent()) {
434 if (optConfig.orElseThrow()) {
435 // Validity check: if parent is config=false this cannot be a config=true
436 InferenceException.throwIf(parentConfig == EffectiveConfig.FALSE, this,
437 "Parent node has config=false, this node must not be specifed as config=true");
438 myConfig = EffectiveConfig.TRUE;
440 myConfig = EffectiveConfig.FALSE;
443 // If "config" statement is not specified, the default is the same as the parent's "config" value.
444 myConfig = parentConfig;
447 myConfig = EffectiveConfig.IGNORED;
450 flags = (byte) (flags & ~MASK_CONFIG | HAVE_CONFIG | myConfig.ordinal());
454 protected abstract boolean isIgnoringConfig();
457 * This method maintains a resolution cache for ignore config, so once we have returned a result, we will
458 * keep on returning the same result without performing any lookups. Exists only to support
459 * {@link SubstatementContext#isIgnoringConfig()}.
462 * Note: use of this method implies that {@link #isConfiguration()} is realized with
463 * {@link #effectiveConfig(StatementContextBase)}.
465 final boolean isIgnoringConfig(final StatementContextBase<?, ?, ?> parent) {
466 return EffectiveConfig.IGNORED == effectiveConfig(parent);
469 protected abstract boolean isIgnoringIfFeatures();
472 * This method maintains a resolution cache for ignore if-feature, so once we have returned a result, we will
473 * keep on returning the same result without performing any lookups. Exists only to support
474 * {@link SubstatementContext#isIgnoringIfFeatures()}.
476 final boolean isIgnoringIfFeatures(final StatementContextBase<?, ?, ?> parent) {
477 final int fl = flags & SET_IGNORE_IF_FEATURE;
479 return fl == SET_IGNORE_IF_FEATURE;
481 if (definition().support().isIgnoringIfFeatures() || parent.isIgnoringIfFeatures()) {
482 flags |= SET_IGNORE_IF_FEATURE;
486 flags |= HAVE_IGNORE_IF_FEATURE;
490 // These two exist only due to memory optimization, should live in AbstractResumedStatement. We are also reusing
491 // this for ReplicaStatementContext's refcount tracking.
492 final boolean fullyDefined() {
496 final void setFullyDefined() {
500 // These two exist only for StatementContextBase. Since we are squeezed for size, with only a single bit available
501 // in flags, we default to 'false' and only set the flag to true when we are absolutely sure -- and all other cases
502 // err on the side of caution by taking the time to evaluate each substatement separately.
503 final boolean allSubstatementsContextIndependent() {
504 return (flags & ALL_INDEPENDENT) != 0;
507 final void setAllSubstatementsContextIndependent() {
508 flags |= ALL_INDEPENDENT;
513 // Common SchemaPath cache. All of this is bound to be removed once YANGTOOLS-1066 is done.
517 // Exists only to support {SubstatementContext,InferredStatementContext}.schemaPath()
519 final @NonNull Optional<SchemaPath> substatementGetSchemaPath() {
520 SchemaPath local = schemaPath;
522 synchronized (this) {
525 schemaPath = local = createSchemaPath((StatementContextBase<?, ?, ?>) coerceParentContext());
530 return Optional.ofNullable(local);
534 private SchemaPath createSchemaPath(final StatementContextBase<?, ?, ?> parent) {
535 final Optional<SchemaPath> maybeParentPath = parent.schemaPath();
536 verify(maybeParentPath.isPresent(), "Parent %s does not have a SchemaPath", parent);
537 final SchemaPath parentPath = maybeParentPath.get();
539 if (StmtContextUtils.isUnknownStatement(this)) {
540 return parentPath.createChild(publicDefinition().getStatementName());
542 final Object argument = argument();
543 if (argument instanceof QName) {
544 final QName qname = (QName) argument;
545 if (producesDeclared(UsesStatement.class)) {
546 return maybeParentPath.orElse(null);
549 return parentPath.createChild(qname);
551 if (argument instanceof String) {
552 // FIXME: This may yield illegal argument exceptions
553 final Optional<StmtContext<A, D, E>> originalCtx = getOriginalCtx();
554 final QName qname = StmtContextUtils.qnameFromArgument(originalCtx.orElse(this), (String) argument);
555 return parentPath.createChild(qname);
557 if (argument instanceof SchemaNodeIdentifier
558 && (producesDeclared(AugmentStatement.class) || producesDeclared(RefineStatement.class)
559 || producesDeclared(DeviationStatement.class))) {
561 return parentPath.createChild(((SchemaNodeIdentifier) argument).getNodeIdentifiers());
564 // FIXME: this does not look right
565 return maybeParentPath.orElse(null);
570 // Reference counting mechanics start. Please keep these methods in one block for clarity. Note this does not
571 // contribute to state visible outside of this package.
576 * Local knowledge of {@link #refcount} values up to statement root. We use this field to prevent recursive lookups
577 * in {@link #noParentRefs(StatementContextBase)} -- once we discover a parent reference once, we keep that
578 * knowledge and update it when {@link #sweep()} is invoked.
580 private byte parentRef = PARENTREF_UNKNOWN;
581 private static final byte PARENTREF_UNKNOWN = -1;
582 private static final byte PARENTREF_ABSENT = 0;
583 private static final byte PARENTREF_PRESENT = 1;
586 * Acquire a reference on this context. As long as there is at least one reference outstanding,
587 * {@link #buildEffective()} will not result in {@link #effectiveSubstatements()} being discarded.
589 * @throws VerifyException if {@link #effectiveSubstatements()} has already been discarded
591 final void incRef() {
592 final int current = refcount;
593 verify(current >= REFCOUNT_NONE, "Attempted to access reference count of %s", this);
594 if (current != REFCOUNT_DEFUNCT) {
595 // Note: can end up becoming REFCOUNT_DEFUNCT on overflow
596 refcount = current + 1;
598 LOG.debug("Disabled refcount increment of {}", this);
603 * Release a reference on this context. This call may result in {@link #effectiveSubstatements()} becoming
606 final void decRef() {
607 final int current = refcount;
608 if (current == REFCOUNT_DEFUNCT) {
610 LOG.debug("Disabled refcount decrement of {}", this);
613 if (current <= REFCOUNT_NONE) {
614 // Underflow, become defunct
615 LOG.warn("Statement refcount underflow, reference counting disabled for {}", this, new Throwable());
616 refcount = REFCOUNT_DEFUNCT;
620 refcount = current - 1;
621 LOG.trace("Refcount {} on {}", refcount, this);
623 if (refcount == REFCOUNT_NONE) {
629 * Return {@code true} if this context has an outstanding reference.
631 * @return True if this context has an outstanding reference.
633 final boolean haveRef() {
634 return refcount > REFCOUNT_NONE;
637 private void lastDecRef() {
638 if (noImplictRef()) {
639 // We are no longer guarded by effective instance
644 final byte prevRefs = parentRef;
645 if (prevRefs == PARENTREF_ABSENT) {
646 // We are the last reference towards root, any children who observed PARENTREF_PRESENT from us need to be
649 } else if (prevRefs == PARENTREF_UNKNOWN) {
650 // Noone observed our parentRef, just update it
651 loadParentRefcount();
655 static final void markNoParentRef(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
656 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
657 final byte prevRef = stmt.parentRef;
658 stmt.parentRef = PARENTREF_ABSENT;
659 if (prevRef == PARENTREF_PRESENT && stmt.refcount == REFCOUNT_NONE) {
660 // Child thinks it is pinned down, update its perspective
661 stmt.markNoParentRef();
666 abstract void markNoParentRef();
668 static final void sweep(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
669 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
675 * Sweep this statement context as a result of {@link #sweepSubstatements()}, i.e. when parent is also being swept.
677 private void sweep() {
678 parentRef = PARENTREF_ABSENT;
679 if (refcount == REFCOUNT_NONE && noImplictRef()) {
680 LOG.trace("Releasing {}", this);
685 static final int countUnswept(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
687 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
688 if (stmt.refcount > REFCOUNT_NONE || !stmt.noImplictRef()) {
696 * Implementation-specific sweep action. This is expected to perform a recursive {@link #sweep(Collection)} on all
697 * {@link #declaredSubstatements()} and {@link #effectiveSubstatements()} and report the result of the sweep
701 * {@link #effectiveSubstatements()} as well as namespaces may become inoperable as a result of this operation.
703 * @return True if the entire tree has been completely swept, false otherwise.
705 abstract int sweepSubstatements();
707 // Called when this statement does not have an implicit reference and have reached REFCOUNT_NONE
708 private void sweepOnDecrement() {
709 LOG.trace("Sweeping on decrement {}", this);
711 // No further parent references, sweep our state.
715 // Propagate towards parent if there is one
716 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
717 if (parent != null) {
718 parent.sweepOnChildDecrement();
722 // Called from child when it has lost its final reference
723 private void sweepOnChildDecrement() {
724 if (isAwaitingChildren()) {
725 // We are a child for which our parent is waiting. Notify it and we are done.
730 // Check parent reference count
731 final int refs = refcount;
732 if (refs > REFCOUNT_NONE || refs <= REFCOUNT_SWEEPING || !noImplictRef()) {
737 // parent is potentially reclaimable
739 LOG.trace("Cleanup {} of parent {}", refcount, this);
741 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
742 if (parent != null) {
743 parent.sweepOnChildDecrement();
749 private boolean noImplictRef() {
750 return effectiveInstance != null || !isSupportedToBuildEffective();
753 private boolean noParentRef() {
754 return parentRefcount() == PARENTREF_ABSENT;
757 private byte parentRefcount() {
759 return (refs = parentRef) != PARENTREF_UNKNOWN ? refs : loadParentRefcount();
762 private byte loadParentRefcount() {
763 return parentRef = calculateParentRefcount();
766 private byte calculateParentRefcount() {
767 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
768 if (parent == null) {
769 return PARENTREF_ABSENT;
771 // There are three possibilities:
772 // - REFCOUNT_NONE, in which case we need to search next parent
773 // - negative (< REFCOUNT_NONE), meaning parent is in some stage of sweeping, hence it does not have
775 // - positive (> REFCOUNT_NONE), meaning parent has an explicit refcount which is holding us down
776 final int refs = parent.refcount;
777 if (refs == REFCOUNT_NONE) {
778 return parent.parentRefcount();
780 return refs < REFCOUNT_NONE ? PARENTREF_ABSENT : PARENTREF_PRESENT;
783 private boolean isAwaitingChildren() {
784 return refcount > REFCOUNT_SWEEPING && refcount < REFCOUNT_NONE;
787 private void sweepOnChildDone() {
788 LOG.trace("Sweeping on child done {}", this);
789 final int current = refcount;
790 if (current >= REFCOUNT_NONE) {
791 // no-op, perhaps we want to handle some cases differently?
792 LOG.trace("Ignoring child sweep of {} for {}", this, current);
795 verify(current != REFCOUNT_SWEPT, "Attempt to sweep a child of swept %s", this);
797 refcount = current + 1;
798 LOG.trace("Child refcount {}", refcount);
799 if (refcount == REFCOUNT_NONE) {
801 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
802 LOG.trace("Propagating to parent {}", parent);
803 if (parent != null && parent.isAwaitingChildren()) {
804 parent.sweepOnChildDone();
809 private void sweepDone() {
810 LOG.trace("Sweep done for {}", this);
811 refcount = REFCOUNT_SWEPT;
815 private boolean sweepState() {
816 refcount = REFCOUNT_SWEEPING;
817 final int childRefs = sweepSubstatements();
818 if (childRefs == 0) {
822 if (childRefs < 0 || childRefs >= REFCOUNT_DEFUNCT) {
823 LOG.warn("Negative child refcount {} cannot be stored, reference counting disabled for {}", childRefs, this,
825 refcount = REFCOUNT_DEFUNCT;
827 LOG.trace("Still {} outstanding children of {}", childRefs, this);
828 refcount = -childRefs;