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.Preconditions.checkArgument;
11 import static com.google.common.base.Verify.verify;
12 import static com.google.common.base.Verify.verifyNotNull;
14 import com.google.common.base.MoreObjects;
15 import com.google.common.base.MoreObjects.ToStringHelper;
16 import com.google.common.base.VerifyException;
17 import java.util.Collection;
19 import java.util.Optional;
21 import org.eclipse.jdt.annotation.NonNull;
22 import org.eclipse.jdt.annotation.Nullable;
23 import org.opendaylight.yangtools.yang.common.QName;
24 import org.opendaylight.yangtools.yang.common.QNameModule;
25 import org.opendaylight.yangtools.yang.common.YangVersion;
26 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
27 import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
28 import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
29 import org.opendaylight.yangtools.yang.model.api.meta.StatementDefinition;
30 import org.opendaylight.yangtools.yang.model.api.stmt.AugmentStatement;
31 import org.opendaylight.yangtools.yang.model.api.stmt.ConfigEffectiveStatement;
32 import org.opendaylight.yangtools.yang.model.api.stmt.DeviationStatement;
33 import org.opendaylight.yangtools.yang.model.api.stmt.RefineStatement;
34 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier;
35 import org.opendaylight.yangtools.yang.model.api.stmt.UsesStatement;
36 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
37 import org.opendaylight.yangtools.yang.parser.spi.meta.CopyType;
38 import org.opendaylight.yangtools.yang.parser.spi.meta.EffectiveStatementState;
39 import org.opendaylight.yangtools.yang.parser.spi.meta.EffectiveStmtCtx.Current;
40 import org.opendaylight.yangtools.yang.parser.spi.meta.InferenceException;
41 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelActionBuilder;
42 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelProcessingPhase;
43 import org.opendaylight.yangtools.yang.parser.spi.meta.ModelProcessingPhase.ExecutionOrder;
44 import org.opendaylight.yangtools.yang.parser.spi.meta.NamespaceBehaviour.Registry;
45 import org.opendaylight.yangtools.yang.parser.spi.meta.ParserNamespace;
46 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext;
47 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext.Mutable;
48 import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContextUtils;
49 import org.opendaylight.yangtools.yang.parser.spi.source.SourceException;
50 import org.opendaylight.yangtools.yang.parser.spi.source.SupportedFeaturesNamespace;
51 import org.opendaylight.yangtools.yang.parser.spi.source.SupportedFeaturesNamespace.SupportedFeatures;
52 import org.slf4j.Logger;
53 import org.slf4j.LoggerFactory;
56 * Real "core" reactor statement implementation of {@link Mutable}, supporting basic reactor lifecycle.
58 * @param <A> Argument type
59 * @param <D> Declared Statement representation
60 * @param <E> Effective Statement representation
62 abstract class ReactorStmtCtx<A, D extends DeclaredStatement<A>, E extends EffectiveStatement<A, D>>
63 extends NamespaceStorageSupport implements Mutable<A, D, E>, Current<A, D> {
64 private static final Logger LOG = LoggerFactory.getLogger(ReactorStmtCtx.class);
67 * Substatement refcount tracking. This mechanics deals with retaining substatements for the purposes of
68 * instantiating their lazy copies in InferredStatementContext. It works in concert with {@link #buildEffective()}
69 * and {@link #declared()}: declared/effective statement views hold an implicit reference and refcount-based
70 * sweep is not activated until they are done (or this statement is not {@link #isSupportedToBuildEffective}).
73 * Reference count is hierarchical in that parent references also pin down their child statements and do not allow
77 * The counter's positive values are tracking incoming references via {@link #incRef()}/{@link #decRef()} methods.
78 * Once we transition to sweeping, this value becomes negative counting upwards to {@link #REFCOUNT_NONE} based on
79 * {@link #sweepOnChildDone()}. Once we reach that, we transition to {@link #REFCOUNT_SWEPT}.
81 private int refcount = REFCOUNT_NONE;
83 * No outstanding references, this statement is a potential candidate for sweeping, provided it has populated its
84 * declared and effective views and {@link #parentRef} is known to be absent.
86 private static final int REFCOUNT_NONE = 0;
88 * Reference count overflow or some other recoverable logic error. Do not rely on refcounts and do not sweep
92 * Note on value assignment:
93 * This allow our incRef() to naturally progress to being saturated. Others jump there directly.
94 * It also makes it it impossible to observe {@code Interger.MAX_VALUE} children, which we take advantage of for
95 * {@link #REFCOUNT_SWEEPING}.
97 private static final int REFCOUNT_DEFUNCT = Integer.MAX_VALUE;
99 * This statement is being actively swept. This is a transient value set when we are sweeping our children, so that
100 * we prevent re-entering this statement.
103 * Note on value assignment:
104 * The value is lower than any legal child refcount due to {@link #REFCOUNT_DEFUNCT} while still being higher than
105 * {@link #REFCOUNT_SWEPT}.
107 private static final int REFCOUNT_SWEEPING = -Integer.MAX_VALUE;
109 * This statement, along with its entire subtree has been swept and we positively know all our children have reached
110 * this state. We {@link #sweepNamespaces()} upon reaching this state.
113 * Note on value assignment:
114 * This is the lowest value observable, making it easier on checking others on equality.
116 private static final int REFCOUNT_SWEPT = Integer.MIN_VALUE;
119 * Effective instance built from this context. This field as dual types. Under normal circumstances in matches the
120 * {@link #buildEffective()} instance. If this context is reused, it can be inflated to {@link EffectiveInstances}
121 * and also act as a common instance reuse site.
123 private @Nullable Object effectiveInstance;
125 // Master flag controlling whether this context can yield an effective statement
126 // FIXME: investigate the mechanics that are being supported by this, as it would be beneficial if we can get rid
127 // of this flag -- eliminating the initial alignment shadow used by below gap-filler fields.
128 private boolean isSupportedToBuildEffective = true;
130 // EffectiveConfig mapping
131 private static final int MASK_CONFIG = 0x03;
132 private static final int HAVE_CONFIG = 0x04;
133 // Effective instantiation mechanics for StatementContextBase: if this flag is set all substatements are known not
134 // change when instantiated. This includes context-independent statements as well as any statements which are
135 // ignored during copy instantiation.
136 private static final int ALL_INDEPENDENT = 0x08;
137 // Flag bit assignments
138 private static final int IS_SUPPORTED_BY_FEATURES = 0x10;
139 private static final int HAVE_SUPPORTED_BY_FEATURES = 0x20;
140 private static final int IS_IGNORE_IF_FEATURE = 0x40;
141 private static final int HAVE_IGNORE_IF_FEATURE = 0x80;
142 // Have-and-set flag constants, also used as masks
143 private static final int SET_SUPPORTED_BY_FEATURES = HAVE_SUPPORTED_BY_FEATURES | IS_SUPPORTED_BY_FEATURES;
144 private static final int SET_IGNORE_IF_FEATURE = HAVE_IGNORE_IF_FEATURE | IS_IGNORE_IF_FEATURE;
146 private static final EffectiveConfig[] EFFECTIVE_CONFIGS;
149 final EffectiveConfig[] values = EffectiveConfig.values();
150 final int length = values.length;
151 verify(length == 4, "Unexpected EffectiveConfig cardinality %s", length);
152 EFFECTIVE_CONFIGS = values;
155 // Flags for use with SubstatementContext. These are hiding in the alignment shadow created by above boolean and
156 // hence improve memory layout.
159 // Flag for use by AbstractResumedStatement, ReplicaStatementContext and InferredStatementContext. Each of them
160 // uses it to indicated a different condition. This is hiding in the alignment shadow created by
161 // 'isSupportedToBuildEffective'.
162 // FIXME: move this out once we have JDK15+
163 private boolean boolFlag;
165 // SchemaPath cache for use with SubstatementContext and InferredStatementContext. This hurts RootStatementContext
166 // a bit in terms of size -- but those are only a few and SchemaPath is on its way out anyway.
167 // FIXME: this should become 'QName'
168 private SchemaPath schemaPath;
174 ReactorStmtCtx(final ReactorStmtCtx<A, D, E> original) {
175 isSupportedToBuildEffective = original.isSupportedToBuildEffective;
176 boolFlag = original.boolFlag;
177 flags = original.flags;
180 // Used by ReplicaStatementContext only
181 ReactorStmtCtx(final ReactorStmtCtx<A, D, E> original, final Void dummy) {
182 boolFlag = isSupportedToBuildEffective = original.isSupportedToBuildEffective;
183 flags = original.flags;
188 // Common public interface contracts with simple mechanics. Please keep this in one logical block, so we do not end
189 // up mixing concerns and simple details with more complex logic.
194 public abstract StatementContextBase<?, ?, ?> getParentContext();
197 public abstract RootStatementContext<?, ?, ?> getRoot();
200 public abstract Collection<? extends StatementContextBase<?, ?, ?>> mutableDeclaredSubstatements();
203 public final @NonNull Registry getBehaviourRegistry() {
204 return getRoot().getBehaviourRegistryImpl();
208 public final YangVersion yangVersion() {
209 return getRoot().getRootVersionImpl();
213 public final void setRootVersion(final YangVersion version) {
214 getRoot().setRootVersionImpl(version);
218 public final void addRequiredSource(final SourceIdentifier dependency) {
219 getRoot().addRequiredSourceImpl(dependency);
223 public final void setRootIdentifier(final SourceIdentifier identifier) {
224 getRoot().setRootIdentifierImpl(identifier);
228 public final boolean isEnabledSemanticVersioning() {
229 return getRoot().isEnabledSemanticVersioningImpl();
233 public final ModelActionBuilder newInferenceAction(final ModelProcessingPhase phase) {
234 return getRoot().getSourceContext().newInferenceAction(phase);
238 public final StatementDefinition publicDefinition() {
239 return definition().getPublicView();
243 public final Parent effectiveParent() {
244 return getParentContext();
248 public final QName moduleName() {
249 final RootStatementContext<?, ?, ?> root = getRoot();
250 return QName.create(StmtContextUtils.getRootModuleQName(root), root.getRawArgument());
254 public final EffectiveStatement<?, ?> original() {
255 return getOriginalCtx().map(StmtContext::buildEffective).orElse(null);
259 // In the next two methods we are looking for an effective statement. If we already have an effective instance,
260 // defer to it's implementation of the equivalent search. Otherwise we search our substatement contexts.
262 // Note that the search function is split, so as to allow InferredStatementContext to do its own thing first.
266 public final <X, Z extends EffectiveStatement<X, ?>> @NonNull Optional<X> findSubstatementArgument(
267 final @NonNull Class<Z> type) {
268 final Object existing = effectiveInstance;
269 return existing != null ? EffectiveInstances.local(existing).findFirstEffectiveSubstatementArgument(type)
270 : findSubstatementArgumentImpl(type);
274 public final boolean hasSubstatement(final @NonNull Class<? extends EffectiveStatement<?, ?>> type) {
275 final Object existing = effectiveInstance;
276 return existing != null ? EffectiveInstances.local(existing).findFirstEffectiveSubstatement(type).isPresent()
277 : hasSubstatementImpl(type);
280 // Visible due to InferredStatementContext's override. At this point we do not have an effective instance available.
281 <X, Z extends EffectiveStatement<X, ?>> @NonNull Optional<X> findSubstatementArgumentImpl(
282 final @NonNull Class<Z> type) {
283 return allSubstatementsStream()
284 .filter(ctx -> ctx.isSupportedToBuildEffective() && ctx.producesEffective(type))
286 .map(ctx -> (X) ctx.getArgument());
289 // Visible due to InferredStatementContext's override. At this point we do not have an effective instance available.
290 boolean hasSubstatementImpl(final @NonNull Class<? extends EffectiveStatement<?, ?>> type) {
291 return allSubstatementsStream()
292 .anyMatch(ctx -> ctx.isSupportedToBuildEffective() && ctx.producesEffective(type));
297 @SuppressWarnings("unchecked")
298 public final <Z extends EffectiveStatement<A, D>> StmtContext<A, D, Z> caerbannog() {
299 return (StmtContext<A, D, Z>) this;
303 public final String toString() {
304 return addToStringAttributes(MoreObjects.toStringHelper(this).omitNullValues()).toString();
307 protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
308 return toStringHelper.add("definition", definition()).add("rawArgument", rawArgument());
312 * Return the context in which this statement was defined.
314 * @return statement definition
316 abstract @NonNull StatementDefinitionContext<A, D, E> definition();
320 // NamespaceStorageSupport/Mutable integration methods. Keep these together.
325 public final <K, V, T extends K, N extends ParserNamespace<K, V>> V namespaceItem(final Class<@NonNull N> type,
327 return getBehaviourRegistry().getNamespaceBehaviour(type).getFrom(this, key);
331 public final <K, V, N extends ParserNamespace<K, V>> Map<K, V> namespace(final Class<@NonNull N> type) {
332 return getNamespace(type);
336 public final <K, V, N extends ParserNamespace<K, V>>
337 Map<K, V> localNamespacePortion(final Class<@NonNull N> type) {
338 return getLocalNamespace(type);
342 protected final void checkLocalNamespaceAllowed(final Class<? extends ParserNamespace<?, ?>> type) {
343 definition().checkNamespaceAllowed(type);
347 protected <K, V, N extends ParserNamespace<K, V>> void onNamespaceElementAdded(final Class<N> type, final K key,
349 // definition().onNamespaceElementAdded(this, type, key, value);
353 * Return the effective statement view of a copy operation. This method may return one of:
355 * <li>{@code this}, when the effective view did not change</li>
356 * <li>an InferredStatementContext, when there is a need for inference-equivalent copy</li>
357 * <li>{@code null}, when the statement failed to materialize</li>
360 * @param parent Proposed new parent
361 * @param type Copy operation type
362 * @param targetModule New target module
363 * @return {@link ReactorStmtCtx} holding effective view
365 abstract @Nullable ReactorStmtCtx<?, ?, ?> asEffectiveChildOf(StatementContextBase<?, ?, ?> parent, CopyType type,
366 QNameModule targetModule);
369 public final ReactorStmtCtx<A, D, E> replicaAsChildOf(final Mutable<?, ?, ?> parent) {
370 checkArgument(parent instanceof StatementContextBase, "Unsupported parent %s", parent);
371 return replicaAsChildOf((StatementContextBase<?, ?, ?>) parent);
374 abstract @NonNull ReplicaStatementContext<A, D, E> replicaAsChildOf(@NonNull StatementContextBase<?, ?, ?> parent);
378 // Statement build entry points -- both public and package-private.
383 public final E buildEffective() {
384 final Object existing;
385 return (existing = effectiveInstance) != null ? EffectiveInstances.local(existing) : loadEffective();
388 private @NonNull E loadEffective() {
389 // Creating an effective statement does not strictly require a declared instance -- there are statements like
390 // 'input', which are implicitly defined.
391 // Our implementation design makes an invariant assumption that buildDeclared() has been called by the time
392 // we attempt to create effective statement:
395 final E ret = createEffective();
396 effectiveInstance = ret;
397 // we have called createEffective(), substatements are no longer guarded by us. Let's see if we can clear up
399 if (refcount == REFCOUNT_NONE) {
405 abstract @NonNull E createEffective();
409 * Attach an effective copy of this statement. This essentially acts as a map, where we make a few assumptions:
411 * <li>{@code copy} and {@code this} statement share {@link #getOriginalCtx()} if it exists</li>
412 * <li>{@code copy} did not modify any statements relative to {@code this}</li>
416 * @param state effective statement state, acting as a lookup key
417 * @param copy New copy to append
418 * @return {@code copy} or a previously-created instances with the same {@code state}
420 @SuppressWarnings("unchecked")
421 final @NonNull E attachCopy(final @NonNull EffectiveStatementState state, final @NonNull E copy) {
422 final Object effective = verifyNotNull(effectiveInstance, "Attaching copy to a unbuilt %s", this);
423 final EffectiveInstances<E> instances;
424 if (effective instanceof EffectiveInstances) {
425 instances = (EffectiveInstances<E>) effective;
427 effectiveInstance = instances = new EffectiveInstances<>((E) effective);
429 return instances.attachCopy(state, copy);
433 * Walk this statement's copy history and return the statement closest to original which has not had its effective
434 * statements modified. This statement and returned substatement logically have the same set of substatements, hence
435 * share substatement-derived state.
437 * @return Closest {@link ReactorStmtCtx} with equivalent effective substatements
439 abstract @NonNull ReactorStmtCtx<A, D, E> unmodifiedEffectiveSource();
442 public final ModelProcessingPhase getCompletedPhase() {
443 return ModelProcessingPhase.ofExecutionOrder(executionOrder());
446 abstract byte executionOrder();
449 * Try to execute current {@link ModelProcessingPhase} of source parsing. If the phase has already been executed,
450 * this method does nothing. This must not be called with {@link ExecutionOrder#NULL}.
452 * @param phase to be executed (completed)
453 * @return true if phase was successfully completed
454 * @throws SourceException when an error occurred in source parsing
456 final boolean tryToCompletePhase(final byte executionOrder) {
457 return executionOrder() >= executionOrder || doTryToCompletePhase(executionOrder);
460 abstract boolean doTryToCompletePhase(byte targetOrder);
464 // Flags-based mechanics. These include public interfaces as well as all the crud we have lurking in our alignment
470 public final boolean isSupportedToBuildEffective() {
471 return isSupportedToBuildEffective;
475 public final void setIsSupportedToBuildEffective(final boolean isSupportedToBuildEffective) {
476 this.isSupportedToBuildEffective = isSupportedToBuildEffective;
480 public final boolean isSupportedByFeatures() {
481 final int fl = flags & SET_SUPPORTED_BY_FEATURES;
483 return fl == SET_SUPPORTED_BY_FEATURES;
485 if (isIgnoringIfFeatures()) {
486 flags |= SET_SUPPORTED_BY_FEATURES;
491 * If parent is supported, we need to check if-features statements of this context.
493 if (isParentSupportedByFeatures()) {
494 // If the set of supported features has not been provided, all features are supported by default.
495 final Set<QName> supportedFeatures = getFromNamespace(SupportedFeaturesNamespace.class,
496 SupportedFeatures.SUPPORTED_FEATURES);
497 if (supportedFeatures == null || StmtContextUtils.checkFeatureSupport(this, supportedFeatures)) {
498 flags |= SET_SUPPORTED_BY_FEATURES;
503 // Either parent is not supported or this statement is not supported
504 flags |= HAVE_SUPPORTED_BY_FEATURES;
508 protected abstract boolean isParentSupportedByFeatures();
511 * Config statements are not all that common which means we are performing a recursive search towards the root
512 * every time {@link #effectiveConfig()} is invoked. This is quite expensive because it causes a linear search
513 * for the (usually non-existent) config statement.
516 * This method maintains a resolution cache, so once we have returned a result, we will keep on returning the same
517 * result without performing any lookups, solely to support {@link #effectiveConfig()}.
520 * Note: use of this method implies that {@link #isIgnoringConfig()} is realized with
521 * {@link #isIgnoringConfig(StatementContextBase)}.
523 final @NonNull EffectiveConfig effectiveConfig(final ReactorStmtCtx<?, ?, ?> parent) {
524 return (flags & HAVE_CONFIG) != 0 ? EFFECTIVE_CONFIGS[flags & MASK_CONFIG] : loadEffectiveConfig(parent);
527 private @NonNull EffectiveConfig loadEffectiveConfig(final ReactorStmtCtx<?, ?, ?> parent) {
528 final EffectiveConfig parentConfig = parent.effectiveConfig();
530 final EffectiveConfig myConfig;
531 if (parentConfig != EffectiveConfig.IGNORED && !definition().support().isIgnoringConfig()) {
532 final Optional<Boolean> optConfig = findSubstatementArgument(ConfigEffectiveStatement.class);
533 if (optConfig.isPresent()) {
534 if (optConfig.orElseThrow()) {
535 // Validity check: if parent is config=false this cannot be a config=true
536 InferenceException.throwIf(parentConfig == EffectiveConfig.FALSE, this,
537 "Parent node has config=false, this node must not be specifed as config=true");
538 myConfig = EffectiveConfig.TRUE;
540 myConfig = EffectiveConfig.FALSE;
543 // If "config" statement is not specified, the default is the same as the parent's "config" value.
544 myConfig = parentConfig;
547 myConfig = EffectiveConfig.IGNORED;
550 flags = (byte) (flags & ~MASK_CONFIG | HAVE_CONFIG | myConfig.ordinal());
554 protected abstract boolean isIgnoringConfig();
557 * This method maintains a resolution cache for ignore config, so once we have returned a result, we will
558 * keep on returning the same result without performing any lookups. Exists only to support
559 * {@link SubstatementContext#isIgnoringConfig()}.
562 * Note: use of this method implies that {@link #isConfiguration()} is realized with
563 * {@link #effectiveConfig(StatementContextBase)}.
565 final boolean isIgnoringConfig(final StatementContextBase<?, ?, ?> parent) {
566 return EffectiveConfig.IGNORED == effectiveConfig(parent);
569 protected abstract boolean isIgnoringIfFeatures();
572 * This method maintains a resolution cache for ignore if-feature, so once we have returned a result, we will
573 * keep on returning the same result without performing any lookups. Exists only to support
574 * {@link SubstatementContext#isIgnoringIfFeatures()}.
576 final boolean isIgnoringIfFeatures(final StatementContextBase<?, ?, ?> parent) {
577 final int fl = flags & SET_IGNORE_IF_FEATURE;
579 return fl == SET_IGNORE_IF_FEATURE;
581 if (definition().support().isIgnoringIfFeatures() || parent.isIgnoringIfFeatures()) {
582 flags |= SET_IGNORE_IF_FEATURE;
586 flags |= HAVE_IGNORE_IF_FEATURE;
590 // These two exist only due to memory optimization, should live in AbstractResumedStatement.
591 final boolean fullyDefined() {
595 final void setFullyDefined() {
599 // This exists only due to memory optimization, should live in ReplicaStatementContext. In this context the flag
600 // indicates the need to drop source's reference count when we are being swept.
601 final boolean haveSourceReference() {
605 // These three exist due to memory optimization, should live in InferredStatementContext. In this context the flag
606 // indicates whether or not this statement's substatement file was modified, i.e. it is not quite the same as the
608 final boolean isModified() {
612 final void setModified() {
616 final void setUnmodified() {
620 // These two exist only for StatementContextBase. Since we are squeezed for size, with only a single bit available
621 // in flags, we default to 'false' and only set the flag to true when we are absolutely sure -- and all other cases
622 // err on the side of caution by taking the time to evaluate each substatement separately.
623 final boolean allSubstatementsContextIndependent() {
624 return (flags & ALL_INDEPENDENT) != 0;
627 final void setAllSubstatementsContextIndependent() {
628 flags |= ALL_INDEPENDENT;
633 // Various functionality from AbstractTypeStatementSupport. This used to work on top of SchemaPath, now it still
634 // lives here. Ultimate future is either proper graduation or (more likely) move to AbstractTypeStatementSupport.
639 public final QName argumentAsTypeQName() {
640 return interpretAsQName(getRawArgument());
644 public final QNameModule effectiveNamespace() {
645 // FIXME: there has to be a better way to do this
646 return getSchemaPath().getLastComponent().getModule();
651 // Common SchemaPath cache. All of this is bound to be removed once YANGTOOLS-1066 is done.
655 // Exists only to support {SubstatementContext,InferredStatementContext}.schemaPath()
657 final @Nullable SchemaPath substatementGetSchemaPath() {
658 if (schemaPath == null) {
659 schemaPath = createSchemaPath((StatementContextBase<?, ?, ?>) coerceParentContext());
664 // FIXME: 7.0.0: this method's logic needs to be moved to the respective StatementSupport classes
666 private SchemaPath createSchemaPath(final StatementContextBase<?, ?, ?> parent) {
667 final SchemaPath parentPath = parent.getSchemaPath();
668 if (StmtContextUtils.isUnknownStatement(this)) {
669 return parentPath.createChild(publicDefinition().getStatementName());
671 final Object argument = argument();
672 if (argument instanceof QName) {
673 final QName qname = (QName) argument;
674 if (producesDeclared(UsesStatement.class)) {
678 return parentPath.createChild(qname);
680 if (argument instanceof String) {
681 return parentPath.createChild(interpretAsQName((String) argument));
683 if (argument instanceof SchemaNodeIdentifier
684 && (producesDeclared(AugmentStatement.class) || producesDeclared(RefineStatement.class)
685 || producesDeclared(DeviationStatement.class))) {
687 return parentPath.createChild(((SchemaNodeIdentifier) argument).getNodeIdentifiers());
690 // FIXME: this does not look right, investigate more?
694 private @NonNull QName interpretAsQName(final String argument) {
695 // FIXME: This may yield illegal argument exceptions
696 return StmtContextUtils.qnameFromArgument(getOriginalCtx().orElse(this), argument);
701 // Reference counting mechanics start. Please keep these methods in one block for clarity. Note this does not
702 // contribute to state visible outside of this package.
707 * Local knowledge of {@link #refcount} values up to statement root. We use this field to prevent recursive lookups
708 * in {@link #noParentRefs(StatementContextBase)} -- once we discover a parent reference once, we keep that
709 * knowledge and update it when {@link #sweep()} is invoked.
711 private byte parentRef = PARENTREF_UNKNOWN;
712 private static final byte PARENTREF_UNKNOWN = -1;
713 private static final byte PARENTREF_ABSENT = 0;
714 private static final byte PARENTREF_PRESENT = 1;
717 * Acquire a reference on this context. As long as there is at least one reference outstanding,
718 * {@link #buildEffective()} will not result in {@link #effectiveSubstatements()} being discarded.
720 * @throws VerifyException if {@link #effectiveSubstatements()} has already been discarded
722 final void incRef() {
723 final int current = refcount;
724 verify(current >= REFCOUNT_NONE, "Attempted to access reference count of %s", this);
725 if (current != REFCOUNT_DEFUNCT) {
726 // Note: can end up becoming REFCOUNT_DEFUNCT on overflow
727 refcount = current + 1;
729 LOG.debug("Disabled refcount increment of {}", this);
734 * Release a reference on this context. This call may result in {@link #effectiveSubstatements()} becoming
737 final void decRef() {
738 final int current = refcount;
739 if (current == REFCOUNT_DEFUNCT) {
741 LOG.debug("Disabled refcount decrement of {}", this);
744 if (current <= REFCOUNT_NONE) {
745 // Underflow, become defunct
746 // FIXME: add a global 'warn once' flag
747 LOG.warn("Statement refcount underflow, reference counting disabled for {}", this, new Throwable());
748 refcount = REFCOUNT_DEFUNCT;
752 refcount = current - 1;
753 LOG.trace("Refcount {} on {}", refcount, this);
755 if (refcount == REFCOUNT_NONE) {
761 * Return {@code true} if this context has no outstanding references.
763 * @return True if this context has no outstanding references.
765 final boolean noRefs() {
766 final int local = refcount;
767 return local < REFCOUNT_NONE || local == REFCOUNT_NONE && noParentRef();
770 private void lastDecRef() {
771 if (noImplictRef()) {
772 // We are no longer guarded by effective instance
777 final byte prevRefs = parentRef;
778 if (prevRefs == PARENTREF_ABSENT) {
779 // We are the last reference towards root, any children who observed PARENTREF_PRESENT from us need to be
782 } else if (prevRefs == PARENTREF_UNKNOWN) {
783 // Noone observed our parentRef, just update it
784 loadParentRefcount();
788 static final void markNoParentRef(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
789 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
790 final byte prevRef = stmt.parentRef;
791 stmt.parentRef = PARENTREF_ABSENT;
792 if (prevRef == PARENTREF_PRESENT && stmt.refcount == REFCOUNT_NONE) {
793 // Child thinks it is pinned down, update its perspective
794 stmt.markNoParentRef();
799 abstract void markNoParentRef();
801 static final void sweep(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
802 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
808 * Sweep this statement context as a result of {@link #sweepSubstatements()}, i.e. when parent is also being swept.
810 private void sweep() {
811 parentRef = PARENTREF_ABSENT;
812 if (refcount == REFCOUNT_NONE && noImplictRef()) {
813 LOG.trace("Releasing {}", this);
818 static final int countUnswept(final Collection<? extends ReactorStmtCtx<?, ?, ?>> substatements) {
820 for (ReactorStmtCtx<?, ?, ?> stmt : substatements) {
821 if (stmt.refcount > REFCOUNT_NONE || !stmt.noImplictRef()) {
829 * Implementation-specific sweep action. This is expected to perform a recursive {@link #sweep(Collection)} on all
830 * {@link #declaredSubstatements()} and {@link #effectiveSubstatements()} and report the result of the sweep
834 * {@link #effectiveSubstatements()} as well as namespaces may become inoperable as a result of this operation.
836 * @return True if the entire tree has been completely swept, false otherwise.
838 abstract int sweepSubstatements();
840 // Called when this statement does not have an implicit reference and have reached REFCOUNT_NONE
841 private void sweepOnDecrement() {
842 LOG.trace("Sweeping on decrement {}", this);
844 // No further parent references, sweep our state.
848 // Propagate towards parent if there is one
849 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
850 if (parent != null) {
851 parent.sweepOnChildDecrement();
855 // Called from child when it has lost its final reference
856 private void sweepOnChildDecrement() {
857 if (isAwaitingChildren()) {
858 // We are a child for which our parent is waiting. Notify it and we are done.
863 // Check parent reference count
864 final int refs = refcount;
865 if (refs > REFCOUNT_NONE || refs <= REFCOUNT_SWEEPING || !noImplictRef()) {
870 // parent is potentially reclaimable
872 LOG.trace("Cleanup {} of parent {}", refcount, this);
874 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
875 if (parent != null) {
876 parent.sweepOnChildDecrement();
882 private boolean noImplictRef() {
883 return effectiveInstance != null || !isSupportedToBuildEffective();
886 private boolean noParentRef() {
887 return parentRefcount() == PARENTREF_ABSENT;
890 private byte parentRefcount() {
892 return (refs = parentRef) != PARENTREF_UNKNOWN ? refs : loadParentRefcount();
895 private byte loadParentRefcount() {
896 return parentRef = calculateParentRefcount();
899 private byte calculateParentRefcount() {
900 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
901 if (parent == null) {
902 return PARENTREF_ABSENT;
904 // There are three possibilities:
905 // - REFCOUNT_NONE, in which case we need to search next parent
906 // - negative (< REFCOUNT_NONE), meaning parent is in some stage of sweeping, hence it does not have
908 // - positive (> REFCOUNT_NONE), meaning parent has an explicit refcount which is holding us down
909 final int refs = parent.refcount;
910 if (refs == REFCOUNT_NONE) {
911 return parent.parentRefcount();
913 return refs < REFCOUNT_NONE ? PARENTREF_ABSENT : PARENTREF_PRESENT;
916 private boolean isAwaitingChildren() {
917 return refcount > REFCOUNT_SWEEPING && refcount < REFCOUNT_NONE;
920 private void sweepOnChildDone() {
921 LOG.trace("Sweeping on child done {}", this);
922 final int current = refcount;
923 if (current >= REFCOUNT_NONE) {
924 // no-op, perhaps we want to handle some cases differently?
925 LOG.trace("Ignoring child sweep of {} for {}", this, current);
928 verify(current != REFCOUNT_SWEPT, "Attempt to sweep a child of swept %s", this);
930 refcount = current + 1;
931 LOG.trace("Child refcount {}", refcount);
932 if (refcount == REFCOUNT_NONE) {
934 final ReactorStmtCtx<?, ?, ?> parent = getParentContext();
935 LOG.trace("Propagating to parent {}", parent);
936 if (parent != null && parent.isAwaitingChildren()) {
937 parent.sweepOnChildDone();
942 private void sweepDone() {
943 LOG.trace("Sweep done for {}", this);
944 refcount = REFCOUNT_SWEPT;
948 private boolean sweepState() {
949 refcount = REFCOUNT_SWEEPING;
950 final int childRefs = sweepSubstatements();
951 if (childRefs == 0) {
955 if (childRefs < 0 || childRefs >= REFCOUNT_DEFUNCT) {
956 // FIXME: add a global 'warn once' flag
957 LOG.warn("Negative child refcount {} cannot be stored, reference counting disabled for {}", childRefs, this,
959 refcount = REFCOUNT_DEFUNCT;
961 LOG.trace("Still {} outstanding children of {}", childRefs, this);
962 refcount = -childRefs;