java.util.concurrent.atomic
Class AtomicInteger

java.lang.Object
  java.util.concurrent.atomic.AtomicInteger

All Implemented Interfaces:

java.io.Serializable

public final class AtomicInteger

extends java.lang.Object

implements java.io.Serializable

An AtomicInteger maintains an int value that is updated atomically. See the package specification for description of the properties of atomic variables.

Since:

1.5

Author:

Doug Lea

See Also:

Serialized Form

Constructor Summary

AtomicInteger()
Create a new AtomicInteger with initial value 0.

AtomicInteger(int initialValue)
Create a new AtomicInteger with the given initial value.

Method Summary

int	addAndGet(int delta) Atomically add the given value to current value.
boolean	compareAndSet(int expect, int update) Atomically set the value to the given updated value if the current value == the expected value.
int	decrementAndGet() Atomically decrement by one the current value.
int	get() Get the current value.
int	getAndAdd(int delta) Atomically add the given value to current value.
int	getAndDecrement() Atomically decrement by one the current value.
int	getAndIncrement() Atomically increment by one the current value.
int	getAndSet(int newValue) Set to the give value and return the old value.
int	incrementAndGet() Atomically increment by one the current value.
void	set(int newValue) Set to the given value.
boolean	weakCompareAndSet(int expect, int update) Atomically set 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, toString, wait, wait, wait

Constructor Detail

AtomicInteger

public AtomicInteger(int initialValue)

Create a new AtomicInteger with the given initial value.

Parameters:

initialValue - the initial value

AtomicInteger

public AtomicInteger()

Create a new AtomicInteger with initial value 0.

Method Detail

get

public int get()

Get the current value.

Returns:

the current value

set

public void set(int newValue)

Set to the given value.

Parameters:

newValue - the new value

getAndSet

public int getAndSet(int newValue)

Set to the give value and return the old value.

Parameters:

newValue - the new value

Returns:

the previous value

compareAndSet

public boolean compareAndSet(int expect,
                             int update)

Atomically set the value to the given updated value if the current value == the expected value.

Parameters:

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 boolean weakCompareAndSet(int expect,
                                 int update)

Atomically set the value to the given updated value if the current value == the expected value. May fail spuriously.

Parameters:

expect - the expected value

update - the new value

Returns:

true if successful.

getAndIncrement

public int getAndIncrement()

Atomically increment by one the current value.

Returns:

the previous value

getAndDecrement

public int getAndDecrement()

Atomically decrement by one the current value.

Returns:

the previous value

getAndAdd

public int getAndAdd(int delta)

Atomically add the given value to current value.

Parameters:

delta - the value to add

Returns:

the previous value

incrementAndGet

public int incrementAndGet()

Atomically increment by one the current value.

Returns:

the updated value

decrementAndGet

public int decrementAndGet()

Atomically decrement by one the current value.

Returns:

the updated value

addAndGet

public int addAndGet(int delta)

Atomically add the given value to current value.

Parameters:

delta - the value to add

Returns:

the updated value