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Treeify SAHashMap #14

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Treeify SAHashMap #14

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47 changes: 35 additions & 12 deletions ObjectLayout-examples/src/main/java/org/ObjectLayout/examples/util/SAAbstractMap.java
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Original file line number Diff line number Diff line change
Expand Up @@ -309,9 +309,28 @@ public void clear() {
* Each of these fields are initialized to contain an instance of the
* appropriate view the first time this view is requested. The views are
* stateless, so there's no reason to create more than one of each.
*
* <p>Since there is no synchronization performed while accessing these fields,
* it is expected that java.util.Map view classes using these fields have
* no non-final fields (or any fields at all except for outer-this). Adhering
* to this rule would make the races on these fields benign.
*
* <p>It is also imperative that implementations read the field only once,
* as in:
*
* <pre> {@code
* public Set<K> keySet() {
* Set<K> ks = keySet; // single racy read
* if (ks == null) {
* ks = new KeySet();
* keySet = ks;
* }
* return ks;
* }
*}</pre>
*/
transient volatile Set<K> keySet;
transient volatile Collection<V> values;
transient Set<K> keySet;
transient Collection<V> values;

/**
* {@inheritDoc}
Expand All @@ -330,8 +349,9 @@ public void clear() {
* method will not all return the same set.
*/
public Set<K> keySet() {
if (keySet == null) {
keySet = new AbstractSet<K>() {
Set<K> ks = keySet;
if (ks == null) {
ks = new AbstractSet<K>() {
public Iterator<K> iterator() {
return new Iterator<K>() {
private Iterator<Entry<K,V>> i = entrySet().iterator();
Expand Down Expand Up @@ -366,8 +386,9 @@ public boolean contains(Object k) {
return SAAbstractMap.this.containsKey(k);
}
};
keySet = ks;
}
return keySet;
return ks;
}

/**
Expand All @@ -387,8 +408,9 @@ public boolean contains(Object k) {
* method will not all return the same collection.
*/
public Collection<V> values() {
if (values == null) {
values = new AbstractCollection<V>() {
Collection<V> vals = values;
if (vals == null) {
vals = new AbstractCollection<V>() {
public Iterator<V> iterator() {
return new Iterator<V>() {
private Iterator<Entry<K,V>> i = entrySet().iterator();
Expand Down Expand Up @@ -423,8 +445,9 @@ public boolean contains(Object v) {
return SAAbstractMap.this.containsValue(v);
}
};
values = vals;
}
return values;
return vals;
}

public abstract Set<Entry<K,V>> entrySet();
Expand Down Expand Up @@ -587,7 +610,7 @@ private static boolean eq(Object o1, Object o2) {
* @since 1.6
*/
public static class SimpleEntry<K,V>
implements Entry<K,V>, java.io.Serializable
implements Entry<K,V>, java.io.Serializable
{
private static final long serialVersionUID = -8499721149061103585L;

Expand Down Expand Up @@ -691,7 +714,7 @@ public boolean equals(Object o) {
*/
public int hashCode() {
return (key == null ? 0 : key.hashCode()) ^
(value == null ? 0 : value.hashCode());
(value == null ? 0 : value.hashCode());
}

/**
Expand All @@ -717,7 +740,7 @@ public String toString() {
* @since 1.6
*/
public static class SimpleImmutableEntry<K,V>
implements Entry<K,V>, java.io.Serializable
implements Entry<K,V>, java.io.Serializable
{
private static final long serialVersionUID = 7138329143949025153L;

Expand Down Expand Up @@ -822,7 +845,7 @@ public boolean equals(Object o) {
*/
public int hashCode() {
return (key == null ? 0 : key.hashCode()) ^
(value == null ? 0 : value.hashCode());
(value == null ? 0 : value.hashCode());
}

/**
Expand Down
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