org.codehaus.groovy.runtime.metaclass
Class BarrierLock

A Serializable class for barrier lock *

Field Summary
 int DEFAULT_INITIAL_CAPACITY
           
 float DEFAULT_LOAD_FACTOR
           
 int MAXIMUM_CAPACITY
           
 int MINIMUM_CAPACITY
           
 BarrierLock barrierLock
           
 int count
           
 Set entrySet
           
 Set keySet
           
 Object lastWrite
           
 float loadFactor
           
 def table
           
 int threshold
           
 Collection values
           
 
Constructor Summary
BarrierLock()
           
 
Method Summary
def ConcurrentReaderHashMap(int initialCapacity, float loadFactor)
           Constructs a new, empty map with the specified initial capacity and the specified load factor.
def ConcurrentReaderHashMap(int initialCapacity)
           Constructs a new, empty map with the specified initial capacity and default load factor.
def ConcurrentReaderHashMap()
           Constructs a new, empty map with a default initial capacity and load factor.
def ConcurrentReaderHashMap(Map t)
           Constructs a new map with the same mappings as the given map.
void clear()
           Removes all mappings from this map.
Object clone()
           Returns a shallow copy of this ConcurrentReaderHashMap instance: the keys and values themselves are not cloned.
boolean contains(Object value)
           Tests if some key maps into the specified value in this table.
boolean containsKey(Object key)
           Tests if the specified object is a key in this table.
boolean containsValue(Object value)
           Returns true if this map maps one or more keys to the specified value.
boolean eq(Object x, Object y)
           Check for equality of non-null references x and y.
Object get(Object key)
           Returns the value to which the specified key is mapped in this table.
def getTableForReading()
           Get ref to table; the reference and the cells it accesses will be at least as fresh as from last use of barrierLock
static int hash(Object x)
           Return hash code for Object x.
boolean isEmpty()
           Returns true if this map contains no key-value mappings.
Set keySet()
           Returns a set view of the keys contained in this map.
int p2capacity(int initialCapacity)
           The default initial number of table slots for this table (32).
Object put(Object key, Object value)
           Maps the specified key to the specified value in this table.
void putAll(Map t)
           Copies all of the mappings from the specified map to this one.
void recordModification(Object x)
           Lock used only for its memory effects.
void rehash()
           Rehashes the contents of this map into a new table with a larger capacity.
Object remove(Object key)
           Removes the key (and its corresponding value) from this table.
int size()
           Returns the number of key-value mappings in this map.
Object sput(Object key, Object value, int hash)
           Continuation of put(), called only when synch lock is held and interference has been detected.
Object sremove(Object key, int hash)
           Continuation of remove(), called only when synch lock is held and interference has been detected.
 

Constructor Detail

BarrierLock

BarrierLock()


Method Detail

ConcurrentReaderHashMap

public def ConcurrentReaderHashMap(int initialCapacity, float loadFactor)
Constructs a new, empty map with the specified initial capacity and the specified load factor.
param:
initialCapacity the initial capacity
The actual initial capacity is rounded to the nearest power of two.
param:
loadFactor the load factor of the ConcurrentReaderHashMap
throws:
IllegalArgumentException if the initial maximum number
of elements is less than zero, or if the load factor is nonpositive.


ConcurrentReaderHashMap

public def ConcurrentReaderHashMap(int initialCapacity)
Constructs a new, empty map with the specified initial capacity and default load factor.
param:
initialCapacity the initial capacity of the
ConcurrentReaderHashMap.
throws:
IllegalArgumentException if the initial maximum number
of elements is less than zero.


ConcurrentReaderHashMap

public def ConcurrentReaderHashMap()
Constructs a new, empty map with a default initial capacity and load factor.


ConcurrentReaderHashMap

public def ConcurrentReaderHashMap(Map t)
Constructs a new map with the same mappings as the given map. The map is created with a capacity of twice the number of mappings in the given map or 16 (whichever is greater), and a default load factor.


clear

public void clear()
Removes all mappings from this map.


clone

public Object clone()
Returns a shallow copy of this ConcurrentReaderHashMap instance: the keys and values themselves are not cloned.
return:
a shallow copy of this map.


contains

public boolean contains(Object value)
Tests if some key maps into the specified value in this table. This operation is more expensive than the containsKey method.

Note that this method is identical in functionality to containsValue, (which is part of the Map interface in the collections framework).

param:
value a value to search for.
return:
true if and only if some key maps to the
value argument in this table as determined by the equals method; false otherwise.
exception:
NullPointerException if the value is null.
see:
#containsKey(Object)
see:
#containsValue(Object)
see:
Map


containsKey

public boolean containsKey(Object key)
Tests if the specified object is a key in this table.
param:
key possible key.
return:
true if and only if the specified object
is a key in this table, as determined by the equals method; false otherwise.
exception:
NullPointerException if the key is
null.
see:
#contains(Object)


containsValue

public boolean containsValue(Object value)
Returns true if this map maps one or more keys to the specified value. Note: This method requires a full internal traversal of the hash table, and so is much slower than method containsKey.
param:
value value whose presence in this map is to be tested.
return:
true if this map maps one or more keys to the
specified value.
exception:
NullPointerException if the value is null.


eq

boolean eq(Object x, Object y)
Check for equality of non-null references x and y.


get

public Object get(Object key)
Returns the value to which the specified key is mapped in this table.
param:
key a key in the table.
return:
the value to which the key is mapped in this table;
null if the key is not mapped to any value in this table.
exception:
NullPointerException if the key is
null.
see:
#put(Object, Object)


getTableForReading

def getTableForReading()
Get ref to table; the reference and the cells it accesses will be at least as fresh as from last use of barrierLock


hash

static int hash(Object x)
Return hash code for Object x. Since we are using power-of-two tables, it is worth the effort to improve hashcode via the same multiplicative scheme as used in IdentityHashMap.


isEmpty

public boolean isEmpty()
Returns true if this map contains no key-value mappings.
return:
true if this map contains no key-value mappings.


keySet

public Set keySet()
Returns a set view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. The set supports element removal, which removes the corresponding mapping from this map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.
return:
a set view of the keys contained in this map.


p2capacity

int p2capacity(int initialCapacity)
The default initial number of table slots for this table (32). Used when not otherwise specified in constructor.


put

public Object put(Object key, Object value)
Maps the specified key to the specified value in this table. Neither the key nor the value can be null.

The value can be retrieved by calling the get method with a key that is equal to the original key.

param:
key the table key.
param:
value the value.
return:
the previous value of the specified key in this table,
or null if it did not have one.
exception:
NullPointerException if the key or value is
null.
see:
Object#equals(Object)
see:
#get(Object)


putAll

public void putAll(Map t)
Copies all of the mappings from the specified map to this one. These mappings replace any mappings that this map had for any of the keys currently in the specified Map.
param:
t Mappings to be stored in this map.


recordModification

void recordModification(Object x)
Lock used only for its memory effects.


rehash

void rehash()
Rehashes the contents of this map into a new table with a larger capacity. This method is called automatically when the number of keys in this map exceeds its capacity and load factor.


remove

public Object remove(Object key)
Removes the key (and its corresponding value) from this table. This method does nothing if the key is not in the table.
param:
key the key that needs to be removed.
return:
the value to which the key had been mapped in this table,
or null if the key did not have a mapping.
exception:
NullPointerException if the key is
null.


size

public int size()
Returns the number of key-value mappings in this map.
return:
the number of key-value mappings in this map.


sput

Object sput(Object key, Object value, int hash)
Continuation of put(), called only when synch lock is held and interference has been detected.


sremove

Object sremove(Object key, int hash)
Continuation of remove(), called only when synch lock is held and interference has been detected.