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com.tangosol.util
Class WrapperCollections.ConcurrentWrapperEntry

java.lang.Object
com.tangosol.util.WrapperCollections.ConcurrentWrapperEntry

All Implemented Interfaces:

java.util.Map.Entry

Enclosing class:

WrapperCollections

public static class WrapperCollections.ConcurrentWrapperEntry

extends java.lang.Object

implements java.util.Map.Entry

Map Entry implementation which uses a ReadWriteLock to manage concurrent access to an underlying Map Entry.

Since:

Coherence 3.7

Field Summary

protected java.util.concurrent.locks.ReadWriteLock	m_lock The read/write lock for concurrency control.
protected java.util.concurrent.locks.Lock	m_lockExclusive The exclusive lock for performing read/write operations.
protected java.util.concurrent.locks.Lock	m_lockShared The shared lock for performing read operations.

Constructor Summary

	WrapperCollections.ConcurrentWrapperEntry(java.util.Map.Entry entry) Create an ConcurrentWrapperEntry which delegates to the specified Map Entry.
protected	WrapperCollections.ConcurrentWrapperEntry(java.util.Map.Entry entry, java.util.concurrent.locks.ReadWriteLock lock) Create an ConcurrentWrapperEntry which delegates to the specified Map Entry.
protected	WrapperCollections.ConcurrentWrapperEntry(java.util.Map.Entry entry, java.util.concurrent.locks.ReadWriteLock lock, boolean fStrict) Create an ConcurrentWrapperEntry which delegates to the specified Map Entry.

Method Summary

boolean	equals(java.lang.Object o) Compares the specified object with this entry for equality.
protected java.util.Map.Entry	getDelegate() Return the Collection to which all operations should be delegated to.
java.lang.Object	getKey() Returns the key corresponding to this entry.
protected java.util.concurrent.locks.ReadWriteLock	getLock() Return the ReadWriteLock that is used to manage concurrent access and modifications to the underlying map.
java.lang.Object	getValue() Returns the value corresponding to this entry.
int	hashCode() Returns the hash code value for this map entry.
java.lang.Object	setValue(java.lang.Object value) Replaces the value corresponding to this entry with the specified value (optional operation).
java.lang.String	toString()

Field Detail

m_lock

protected final java.util.concurrent.locks.ReadWriteLock m_lock

The read/write lock for concurrency control.

m_lockShared

protected final java.util.concurrent.locks.Lock m_lockShared

The shared lock for performing read operations.

Note: This field is null if read-only operations are not supposed to be protected, i.e. if the "strict" option is not used.

m_lockExclusive

protected final java.util.concurrent.locks.Lock m_lockExclusive

The exclusive lock for performing read/write operations.

Constructor Detail

WrapperCollections.ConcurrentWrapperEntry

public WrapperCollections.ConcurrentWrapperEntry(java.util.Map.Entry entry)

Create an ConcurrentWrapperEntry which delegates to the specified Map Entry.

Parameters:

entry - the Map Entry to delegate all calls to

WrapperCollections.ConcurrentWrapperEntry

protected WrapperCollections.ConcurrentWrapperEntry(java.util.Map.Entry entry,
                                                    java.util.concurrent.locks.ReadWriteLock lock)

Create an ConcurrentWrapperEntry which delegates to the specified Map Entry.

Parameters:

entry - the Map Entry to delegate all calls to

lock - a read/write lock for concurrency management

WrapperCollections.ConcurrentWrapperEntry

protected WrapperCollections.ConcurrentWrapperEntry(java.util.Map.Entry entry,
                                                    java.util.concurrent.locks.ReadWriteLock lock,
                                                    boolean fStrict)

Create an ConcurrentWrapperEntry which delegates to the specified Map Entry.

Parameters:

entry - the Map Entry to delegate all calls to

lock - a read/write lock for concurrency management

fStrict - pass true to protect all Entry methods; false to protect only the setValue() method

Method Detail

getKey

public java.lang.Object getKey()

Returns the key corresponding to this entry.

Specified by:

getKey in interface java.util.Map.Entry

Returns:

the key corresponding to this entry.

getValue

public java.lang.Object getValue()

Returns the value corresponding to this entry. If the mapping has been removed from the backing map (by the iterator's remove operation), the results of this call are undefined.

Specified by:

getValue in interface java.util.Map.Entry

Returns:

the value corresponding to this entry.

setValue

public java.lang.Object setValue(java.lang.Object value)

Replaces the value corresponding to this entry with the specified value (optional operation). (Writes through to the map.) The behavior of this call is undefined if the mapping has already been removed from the map (by the iterator's remove operation).

Specified by:

setValue in interface java.util.Map.Entry

Parameters:

value - new value to be stored in this entry.

Returns:

old value corresponding to the entry.

equals

public boolean equals(java.lang.Object o)

Compares the specified object with this entry for equality. Returns true if the given object is also a map entry and the two entries represent the same mapping. More formally, two entries e1 and e2 represent the same mapping if

     (e1.getKey()==null ?
      e2.getKey()==null : e1.getKey().equals(e2.getKey()))  &&
     (e1.getValue()==null ?
      e2.getValue()==null : e1.getValue().equals(e2.getValue()))
 

This ensures that the equals method works properly across different implementations of the Map.Entry interface.

Specified by:

equals in interface java.util.Map.Entry

Parameters:

o - object to be compared for equality with this map entry.

Returns:

true if the specified object is equal to this map entry.

hashCode

public int hashCode()

Returns the hash code value for this map entry. The hash code of a map entry e is defined to be:

     (e.getKey()==null   ? 0 : e.getKey().hashCode()) ^
     (e.getValue()==null ? 0 : e.getValue().hashCode())
 

This ensures that e1.equals(e2) implies that e1.hashCode()==e2.hashCode() for any two Entries e1 and e2, as required by the general contract of Object.hashCode.

Specified by:

hashCode in interface java.util.Map.Entry

Returns:

the hash code value for this map entry.

See Also:

Object.hashCode(), Object.equals(Object), Map.Entry.equals(Object)

toString

public java.lang.String toString()

getDelegate

protected java.util.Map.Entry getDelegate()

Return the Collection to which all operations should be delegated to.

Returns:

the wrapped Collection

getLock

protected java.util.concurrent.locks.ReadWriteLock getLock()

Return the ReadWriteLock that is used to manage concurrent access and modifications to the underlying map.

Returns:

the ReadWriteLock

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