*/
package org.opendaylight.yangtools.triemap;
+import static org.opendaylight.yangtools.triemap.LookupResult.RESTART;
+import static org.opendaylight.yangtools.triemap.PresencePredicate.ABSENT;
+import static org.opendaylight.yangtools.triemap.PresencePredicate.PRESENT;
+
import java.util.Optional;
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
-final class INode<K, V> extends INodeBase<K, V> {
- static final Object KEY_PRESENT = new Object ();
- static final Object KEY_ABSENT = new Object ();
+final class INode<K, V> extends BasicNode {
+ @SuppressWarnings("rawtypes")
+ private static final AtomicReferenceFieldUpdater<INode, MainNode> MAINNODE_UPDATER =
+ AtomicReferenceFieldUpdater.newUpdater(INode.class, MainNode.class, "mainnode");
- /**
- * Virtual result for lookup methods indicating that the lookup needs to be restarted. This is a faster version
- * of throwing a checked exception to control the restart.
- */
- static final Object RESTART = new Object();
+ private final Gen gen;
- INode(final Gen gen, final MainNode<K, V> bn) {
- super(gen, bn);
+ private volatile MainNode<K, V> mainnode;
+
+ INode(final Gen gen, final MainNode<K, V> mainnode) {
+ this.gen = gen;
+ this.mainnode = mainnode;
}
MainNode<K, V> gcasRead(final TrieMap<K, V> ct) {
}
MainNode<K, V> GCAS_READ(final TrieMap<K, V> ct) {
- MainNode<K, V> m = /* READ */ READ();
+ MainNode<K, V> m = /* READ */ mainnode;
MainNode<K, V> prevval = /* READ */ m.READ_PREV();
if (prevval == null) {
return m;
if (prev instanceof FailedNode) {
// try to commit to previous value
FailedNode<K, V> fn = (FailedNode<K, V>) prev;
- if (CAS(m, fn.READ_PREV())) {
+ if (MAINNODE_UPDATER.compareAndSet(this, m, fn.READ_PREV())) {
return fn.READ_PREV();
}
- // Tail recursion: return GCAS_Complete (/* READ */ READ(), ct);
- m = /* READ */ READ();
+ // Tail recursion: return GCAS_Complete (/* READ */ mainnode, ct);
+ m = /* READ */ mainnode;
continue;
}
// ==> if `ctr.gen` = `gen` then they are both equal to G.
// ==> otherwise, we know that either `ctr.gen` > G, `gen` < G,
// or both
- if ((ctr.gen == gen) && ct.nonReadOnly()) {
+ if (ctr.gen == gen && !ct.isReadOnly()) {
// try to commit
if (m.CAS_PREV(prev, null)) {
return m;
// try to abort
m.CAS_PREV(prev, new FailedNode<>(prev));
- // Tail recursion: return GCAS_Complete(/* READ */ READ(), ct);
- m = /* READ */ READ();
+ // Tail recursion: return GCAS_Complete(/* READ */ mainnode, ct);
+ m = /* READ */ mainnode;
}
}
private boolean GCAS(final MainNode<K, V> old, final MainNode<K, V> n, final TrieMap<K, V> ct) {
n.WRITE_PREV(old);
- if (CAS(old, n)) {
+ if (MAINNODE_UPDATER.compareAndSet(this, old, n)) {
GCAS_Complete(n, ct);
return /* READ */ n.READ_PREV() == null;
}
*
* @return true if successful, false otherwise
*/
- boolean rec_insert(final K k, final V v, final int hc, final int lev, final INode<K, V> parent, final Gen startgen,
+ boolean rec_insert(final K k, final V v, final int hc, final int lev, final INode<K, V> parent,
final TrieMap<K, V> ct) {
+ return rec_insert(k, v, hc, lev, parent, gen, ct);
+ }
+
+ private boolean rec_insert(final K k, final V v, final int hc, final int lev, final INode<K, V> parent,
+ final Gen startgen, final TrieMap<K, V> ct) {
while (true) {
final MainNode<K, V> m = GCAS_READ (ct); // use -Yinline!
* previous value bound to the key)
*/
Optional<V> rec_insertif(final K k, final V v, final int hc, final Object cond, final int lev,
+ final INode<K, V> parent, final TrieMap<K, V> ct) {
+ return rec_insertif(k, v, hc, cond, lev, parent, gen, ct);
+ }
+
+ private Optional<V> rec_insertif(final K k, final V v, final int hc, final Object cond, final int lev,
final INode<K, V> parent, final Gen startgen, final TrieMap<K, V> ct) {
while (true) {
final MainNode<K, V> m = GCAS_READ(ct); // use -Yinline!
}
return null;
- } else if (cond == INode.KEY_ABSENT) {
+ } else if (cond == ABSENT) {
if (sn.hc == hc && ct.equal(sn.k, k)) {
return Optional.of(sn.v);
}
}
return null;
- } else if (cond == INode.KEY_PRESENT) {
+ } else if (cond == PRESENT) {
if (sn.hc == hc && ct.equal(sn.k, k)) {
if (GCAS(cn, cn.updatedAt(pos, new SNode<>(k, v, hc), gen), ct)) {
return Optional.of(sn.v);
return Optional.empty();
}
}
- } else if (cond == null || cond == INode.KEY_ABSENT) {
+ } else if (cond == null || cond == ABSENT) {
final CNode<K, V> rn = (cn.gen == gen) ? cn : cn.renewed(gen, ct);
final CNode<K, V> ncnode = rn.insertedAt (pos, flag, new SNode<>(k, v, hc), gen);
if (GCAS(cn, ncnode, ct)) {
}
return null;
- } else if (cond == INode.KEY_PRESENT) {
- return Optional.empty();
} else {
return Optional.empty();
}
return optv;
}
return null;
- } else if (cond == INode.KEY_ABSENT) {
+ } else if (cond == ABSENT) {
final Optional<V> t = ln.get(k);
if (t.isPresent()) {
return t;
return Optional.empty();
}
return null;
- } else if (cond == INode.KEY_PRESENT) {
+ } else if (cond == PRESENT) {
final Optional<V> t = ln.get(k);
if (!t.isPresent()) {
return t;
* @return null if no value has been found, RESTART if the operation
* wasn't successful, or any other value otherwise
*/
- Object rec_lookup(final K k, final int hc, final int lev, final INode<K, V> parent, final Gen startgen,
+ Object rec_lookup(final K k, final int hc, final int lev, final INode<K, V> parent, final TrieMap<K, V> ct) {
+ return rec_lookup(k, hc, lev, parent, gen, ct);
+ }
+
+ private Object rec_lookup(final K k, final int hc, final int lev, final INode<K, V> parent, final Gen startgen,
final TrieMap<K, V> ct) {
while (true) {
final MainNode<K, V> m = GCAS_READ(ct); // use -Yinline!
continue;
}
- // used to be throw RestartException
return RESTART;
} else if (sub instanceof SNode) {
// 2) singleton node
return cleanReadOnly((TNode<K, V>) m, lev, parent, ct, k, hc);
} else if (m instanceof LNode) {
// 5) an l-node
- return ((LNode<K, V>) m).get(k);
+ return ((LNode<K, V>) m).get(k).orElse(null);
} else {
throw new IllegalStateException("Unhandled node " + m);
}
private Object cleanReadOnly(final TNode<K, V> tn, final int lev, final INode<K, V> parent,
final TrieMap<K, V> ct, final K k, final int hc) {
- if (ct.nonReadOnly()) {
- // used to be throw RestartException
- clean(parent, ct, lev - 5);
- return RESTART;
- }
+ if (ct.isReadOnly()) {
+ if (tn.hc == hc && ct.equal(tn.k, k)) {
+ return tn.v;
+ }
- if (tn.hc == hc && ct.equal(tn.k, k)) {
- return tn.v;
+ return null;
}
- return null;
+ clean(parent, ct, lev - 5);
+ return RESTART;
}
/**
* value otherwise
*/
Optional<V> rec_remove(final K k, final V v, final int hc, final int lev, final INode<K, V> parent,
+ final TrieMap<K, V> ct) {
+ return rec_remove(k, v, hc, lev, parent, gen, ct);
+ }
+
+ private Optional<V> rec_remove(final K k, final V v, final int hc, final int lev, final INode<K, V> parent,
final Gen startgen, final TrieMap<K, V> ct) {
final MainNode<K, V> m = GCAS_READ(ct); // use -Yinline!