edu.emory.mathcs.backport.java.util.concurrent.atomic

Class AtomicIntegerArray

public class AtomicIntegerArray extends Object implements Serializable

An {@code int} array in which elements may be updated atomically. See the edu.emory.mathcs.backport.java.util.concurrent.atomic package specification for description of the properties of atomic variables.

Since: 1.5

Author: Doug Lea

Constructor Summary
AtomicIntegerArray(int length)
Creates a new AtomicIntegerArray of given length.
AtomicIntegerArray(int[] array)
Creates a new AtomicIntegerArray with the same length as, and all elements copied from, the given array.
Method Summary
intaddAndGet(int i, int delta)
Atomically adds the given value to the element at index {@code i}.
booleancompareAndSet(int i, int expect, int update)
Atomically sets the element at position {@code i} to the given updated value if the current value {@code ==} the expected value.
intdecrementAndGet(int i)
Atomically decrements by one the element at index {@code i}.
intget(int i)
Gets the current value at position {@code i}.
intgetAndAdd(int i, int delta)
Atomically adds the given value to the element at index {@code i}.
intgetAndDecrement(int i)
Atomically decrements by one the element at index {@code i}.
intgetAndIncrement(int i)
Atomically increments by one the element at index {@code i}.
intgetAndSet(int i, int newValue)
Atomically sets the element at position {@code i} to the given value and returns the old value.
intincrementAndGet(int i)
Atomically increments by one the element at index {@code i}.
voidlazySet(int i, int newValue)
Eventually sets the element at position {@code i} to the given value.
intlength()
Returns the length of the array.
voidset(int i, int newValue)
Sets the element at position {@code i} to the given value.
StringtoString()
Returns the String representation of the current values of array.
booleanweakCompareAndSet(int i, int expect, int update)
Atomically sets the element at position {@code i} to the given updated value if the current value {@code ==} the expected value.

Constructor Detail

AtomicIntegerArray

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

Parameters: length the length of the array

AtomicIntegerArray

public AtomicIntegerArray(int[] array)
Creates a new AtomicIntegerArray 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

addAndGet

public final int addAndGet(int i, int delta)
Atomically adds the given value to the element at index {@code i}.

Parameters: i the index delta the value to add

Returns: the updated value

compareAndSet

public final boolean compareAndSet(int i, int expect, int update)
Atomically sets the element at position {@code i} to the given updated value if the current value {@code ==} 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.

decrementAndGet

public final int decrementAndGet(int i)
Atomically decrements by one the element at index {@code i}.

Parameters: i the index

Returns: the updated value

get

public final int get(int i)
Gets the current value at position {@code i}.

Parameters: i the index

Returns: the current value

getAndAdd

public final int getAndAdd(int i, int delta)
Atomically adds the given value to the element at index {@code i}.

Parameters: i the index delta the value to add

Returns: the previous value

getAndDecrement

public final int getAndDecrement(int i)
Atomically decrements by one the element at index {@code i}.

Parameters: i the index

Returns: the previous value

getAndIncrement

public final int getAndIncrement(int i)
Atomically increments by one the element at index {@code i}.

Parameters: i the index

Returns: the previous value

getAndSet

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

Parameters: i the index newValue the new value

Returns: the previous value

incrementAndGet

public final int incrementAndGet(int i)
Atomically increments by one the element at index {@code i}.

Parameters: i the index

Returns: the updated value

lazySet

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

Parameters: i the index newValue the new value

Since: 1.6

length

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

Returns: the length of the array

set

public final void set(int i, int newValue)
Sets the element at position {@code i} to the given value.

Parameters: i the index newValue the new value

toString

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

Returns: the String representation of the current values of array.

weakCompareAndSet

public final boolean weakCompareAndSet(int i, int expect, int update)
Atomically sets the element at position {@code i} to the given updated value if the current value {@code ==} the expected value.

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

Parameters: i the index expect the expected value update the new value

Returns: true if successful.