edu.emory.mathcs.util.concurrent.atomic
Class AtomicLong

java.lang.Object
  |
  +--java.lang.Number
        |
        +--edu.emory.mathcs.util.concurrent.atomic.AtomicLong
All Implemented Interfaces:
java.io.Serializable

public class AtomicLong
extends java.lang.Number
implements java.io.Serializable

A long value that may be updated atomically. See the edu.emory.mathcs.util.concurrent.atomic package specification for description of the properties of atomic variables. An AtomicLong is used in applications such as atomically incremented sequence numbers, and cannot be used as a replacement for a Long. However, this class does extend Number to allow uniform access by tools and utilities that deal with numerically-based classes.

Since:
1.5
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.
 double doubleValue()
           
 float floatValue()
           
 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.
 int intValue()
           
 long longValue()
           
 void set(long newValue)
          Set to the given value.
 java.lang.String toString()
          Returns the String representation of the current 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.Number
byteValue, shortValue
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, 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 final long get()
Get the current value.

Returns:
the current value

set

public final void set(long newValue)
Set to the given value.

Parameters:
newValue - the new value

getAndSet

public final 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 final 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 final 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 final long getAndIncrement()
Atomically increment by one the current value.

Returns:
the previous value

getAndDecrement

public final long getAndDecrement()
Atomically decrement by one the current value.

Returns:
the previous value

getAndAdd

public final long getAndAdd(long delta)
Atomically add the given value to current value.

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

incrementAndGet

public final long incrementAndGet()
Atomically increment by one the current value.

Returns:
the updated value

decrementAndGet

public final long decrementAndGet()
Atomically decrement by one the current value.

Returns:
the updated value

addAndGet

public final long addAndGet(long delta)
Atomically add the given value to current value.

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

toString

public java.lang.String toString()
Returns the String representation of the current value.

Overrides:
toString in class java.lang.Object
Returns:
the String representation of the current value.

intValue

public int intValue()
Specified by:
intValue in class java.lang.Number

longValue

public long longValue()
Specified by:
longValue in class java.lang.Number

floatValue

public float floatValue()
Specified by:
floatValue in class java.lang.Number

doubleValue

public double doubleValue()
Specified by:
doubleValue in class java.lang.Number