java.util.concurrent.atomic
Class AtomicLong

java.lang.Object
  java.util.concurrent.atomic.AtomicLong

All Implemented Interfaces:

java.io.Serializable

public final class AtomicLong

extends java.lang.Object

implements java.io.Serializable

An AtomicLong maintains a long 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

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

AtomicLong(long initialValue)
Create a new AtomicLong with the given initial value.

Method Summary

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

AtomicLong

public AtomicLong(long initialValue)

Create a new AtomicLong with the given initial value.

Parameters:

initialValue - the initial value

AtomicLong

public AtomicLong()

Create a new AtomicLong with initial value 0.

Method Detail

get

public long get()

Get the current value.

Returns:

the current value

set

public void set(long newValue)

Set to the given value.

Parameters:

newValue - the new value

getAndSet

public long getAndSet(long newValue)

Set to the give value and return the old value.

Parameters:

newValue - the new value

Returns:

the previous value

compareAndSet

public boolean compareAndSet(long expect,
                             long 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(long expect,
                                 long 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 long getAndIncrement()

Atomically increment by one the current value.

Returns:

the previous value

getAndDecrement

public long getAndDecrement()

Atomically decrement by one the current value.

Returns:

the previous value

getAndAdd

public long getAndAdd(long delta)

Atomically add the given value to current value.

Parameters:

delta - the value to add

Returns:

the previous value

incrementAndGet

public long incrementAndGet()

Atomically increment by one the current value.

Returns:

the updated value

decrementAndGet

public long decrementAndGet()

Atomically decrement by one the current value.

Returns:

the updated value

addAndGet

public long addAndGet(long delta)

Atomically add the given value to current value.

Parameters:

delta - the value to add

Returns:

the updated value