站内搜索: 请输入搜索关键词
当前页面: 在线文档首页 > JDK 5 Documentation v6.0, Java 2 SDK 英文文档

AtomicLongArray (Java Platform SE 6) - JDK 5 Documentation v6.0, Java 2 SDK 英文文档


Java™ Platform
Standard Ed. 6

java.util.concurrent.atomic
Class AtomicLongArray

java.lang.Object
  extended by java.util.concurrent.atomic.AtomicLongArray
All Implemented Interfaces:
Serializable

public class AtomicLongArray
extends Object
implements Serializable

A long array in which elements may be updated atomically. See the java.util.concurrent.atomic package specification for description of the properties of atomic variables.

Since:
1.5
See Also:
Serialized Form

Constructor Summary
AtomicLongArray(int length)
          Creates a new AtomicLongArray of given length.
AtomicLongArray(long[] array)
          Creates a new AtomicLongArray with the same length as, and all elements copied from, the given array.
 
Method Summary
 long addAndGet(int i, long delta)
          Atomically adds the given value to the element at index i.
 boolean compareAndSet(int i, long expect, long update)
          Atomically sets the value to the given updated value if the current value == the expected value.
 long decrementAndGet(int i)
          Atomically decrements by one the element at index i.
 long get(int i)
          Gets the current value at position i.
 long getAndAdd(int i, long delta)
          Atomically adds the given value to the element at index i.
 long getAndDecrement(int i)
          Atomically decrements by one the element at index i.
 long getAndIncrement(int i)
          Atomically increments by one the element at index i.
 long getAndSet(int i, long newValue)
          Atomically sets the element at position i to the given value and returns the old value.
 long incrementAndGet(int i)
          Atomically increments by one the element at index i.
 void lazySet(int i, long newValue)
          Eventually sets the element at position i to the given value.
 int length()
          Returns the length of the array.
 void set(int i, long newValue)
          Sets the element at position i to the given value.
 String toString()
          Returns the String representation of the current values of array.
 boolean weakCompareAndSet(int i, long expect, long update)
          Atomically sets the value to the given updated value if the current value == the expected value.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

AtomicLongArray

public AtomicLongArray(int length)
Creates a new AtomicLongArray of given length.

Parameters:
length - the length of the array

AtomicLongArray

public AtomicLongArray(long[] array)
Creates a new AtomicLongArray with the same length as, and all elements copied from, the given array.

Parameters:
array - the array to copy elements from
Throws:
NullPointerException - if array is null
Method Detail

length

public final int length()
Returns the length of the array.

Returns:
the length of the array

get

public final long get(int i)
Gets the current value at position i.

Parameters:
i - the index
Returns:
the current value

set

public final void set(int i,
                      long newValue)
Sets the element at position i to the given value.

Parameters:
i - the index
newValue - the new value

lazySet

public final void lazySet(int i,
                          long newValue)
Eventually sets the element at position i to the given value.

Parameters:
i - the index
newValue - the new value
Since:
1.6

getAndSet

public final long getAndSet(int i,
                            long newValue)
Atomically sets the element at position i to the given value and returns the old value.

Parameters:
i - the index
newValue - the new value
Returns:
the previous value

compareAndSet

public final boolean compareAndSet(int i,
                                   long expect,
                                   long update)
Atomically sets the value to the given updated value if the current value == the expected value.

Parameters:
i - the index
expect - the expected value
update - the new value
Returns:
true if successful. False return indicates that the actual value was not equal to the expected value.

weakCompareAndSet

public final boolean weakCompareAndSet(int i,
                                       long expect,
                                       long update)
Atomically sets the value to the given updated value if the current value == the expected value.

May fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to compareAndSet.

Parameters:
i - the index
expect - the expected value
update - the new value
Returns:
true if successful.

getAndIncrement

public final long getAndIncrement(int i)
Atomically increments by one the element at index i.

Parameters:
i - the index
Returns:
the previous value

getAndDecrement

public final long getAndDecrement(int i)
Atomically decrements by one the element at index i.

Parameters:
i - the index
Returns:
the previous value

getAndAdd

public final long getAndAdd(int i,
                            long delta)
Atomically adds the given value to the element at index i.

Parameters:
i - the index
delta - the value to add
Returns:
the previous value

incrementAndGet

public final long incrementAndGet(int i)
Atomically increments by one the element at index i.

Parameters:
i - the index
Returns:
the updated value

decrementAndGet

public final long decrementAndGet(int i)
Atomically decrements by one the element at index i.

Parameters:
i - the index
Returns:
the updated value

addAndGet

public long addAndGet(int i,
                      long delta)
Atomically adds the given value to the element at index i.

Parameters:
i - the index
delta - the value to add
Returns:
the updated value

toString

public String toString()
Returns the String representation of the current values of array.

Overrides:
toString in class Object
Returns:
the String representation of the current values of array.

Java™ Platform
Standard Ed. 6

Submit a bug or feature
For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2006 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.