Package org.jboss.netty.util.internal
Class ConcurrentIdentityHashMap.Segment<K,V>
java.lang.Object
java.util.concurrent.locks.ReentrantLock
org.jboss.netty.util.internal.ConcurrentIdentityHashMap.Segment<K,V>
- All Implemented Interfaces:
Serializable
,Lock
- Enclosing class:
- ConcurrentIdentityHashMap<K,
V>
Segments are specialized versions of hash tables. This subclasses from
ReentrantLock opportunistically, just to simplify some locking and avoid
separate construction.
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Field Summary
FieldsModifier and TypeFieldDescription(package private) int
The number of elements in this segment's region.(package private) final float
The load factor for the hash table.(package private) int
Number of updates that alter the size of the table.private static final long
(package private) ConcurrentIdentityHashMap.HashEntry<K,
V>[] The per-segment table.(package private) int
The table is rehashed when its size exceeds this threshold. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescription(package private) void
clear()
(package private) boolean
containsKey
(Object key, int hash) (package private) boolean
containsValue
(Object value) (package private) V
(package private) ConcurrentIdentityHashMap.HashEntry<K,
V> getFirst
(int hash) Returns properly casted first entry of bin for given hash.private static boolean
(package private) static <K,
V> ConcurrentIdentityHashMap.Segment<K, V>[] newArray
(int i) (package private) ConcurrentIdentityHashMap.HashEntry<K,
V> newHashEntry
(K key, int hash, ConcurrentIdentityHashMap.HashEntry<K, V> next, V value) (package private) V
(package private) V
Reads value field of an entry under lock.(package private) int
rehash()
(package private) V
Remove; match on key only if value null, else match both.(package private) V
(package private) boolean
(package private) void
setTable
(ConcurrentIdentityHashMap.HashEntry<K, V>[] newTable) Sets table to new HashEntry array.Methods inherited from class java.util.concurrent.locks.ReentrantLock
getHoldCount, getOwner, getQueuedThreads, getQueueLength, getWaitingThreads, getWaitQueueLength, hasQueuedThread, hasQueuedThreads, hasWaiters, isFair, isHeldByCurrentThread, isLocked, lock, lockInterruptibly, newCondition, toString, tryLock, tryLock, unlock
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Field Details
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serialVersionUID
private static final long serialVersionUID- See Also:
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count
transient volatile int countThe number of elements in this segment's region. -
modCount
int modCountNumber of updates that alter the size of the table. This is used during bulk-read methods to make sure they see a consistent snapshot: If modCounts change during a traversal of segments computing size or checking containsValue, then we might have an inconsistent view of state so (usually) must retry. -
threshold
int thresholdThe table is rehashed when its size exceeds this threshold. (The value of this field is always (capacity * loadFactor).) -
table
The per-segment table. -
loadFactor
final float loadFactorThe load factor for the hash table. Even though this value is same for all segments, it is replicated to avoid needing links to outer object.
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Constructor Details
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Segment
Segment(int initialCapacity, float lf)
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Method Details
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newArray
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keyEq
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setTable
Sets table to new HashEntry array. Call only while holding lock or in constructor. -
getFirst
Returns properly casted first entry of bin for given hash. -
newHashEntry
ConcurrentIdentityHashMap.HashEntry<K,V> newHashEntry(K key, int hash, ConcurrentIdentityHashMap.HashEntry<K, V> next, V value) -
readValueUnderLock
Reads value field of an entry under lock. Called if value field ever appears to be null. This is possible only if a compiler happens to reorder a HashEntry initialization with its table assignment, which is legal under memory model but is not known to ever occur. -
get
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containsKey
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containsValue
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replace
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replace
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put
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rehash
int rehash() -
remove
Remove; match on key only if value null, else match both. -
clear
void clear()
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