java.util.concurrent.atomic

Class AtomicLongArray

java.lang.Object

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

Author:

Doug Lea

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AtomicLongArray(int length) Creates a new AtomicLongArray of the given length, with all elements initially zero.
AtomicLongArray(long[] array) Creates a new AtomicLongArray with the same length as, and all elements copied from, the given array.

Method Summary

Modifier and Type	Method and Description
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 element at position i 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 element at position i 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 the given length, with all elements initially zero.

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 element at position i 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 element at position i 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