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

Class AtomicLong

public class AtomicLong extends Number implements Serializable

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

Since: 1.5

Author: Doug Lea

Constructor Summary
AtomicLong(long initialValue)
Creates a new AtomicLong with the given initial value.
AtomicLong()
Creates a new AtomicLong with initial value {@code 0}.
Method Summary
longaddAndGet(long delta)
Atomically adds the given value to the current value.
booleancompareAndSet(long expect, long update)
Atomically sets the value to the given updated value if the current value {@code ==} the expected value.
longdecrementAndGet()
Atomically decrements by one the current value.
doubledoubleValue()
floatfloatValue()
longget()
Gets the current value.
longgetAndAdd(long delta)
Atomically adds the given value to the current value.
longgetAndDecrement()
Atomically decrements by one the current value.
longgetAndIncrement()
Atomically increments by one the current value.
longgetAndSet(long newValue)
Atomically sets to the given value and returns the old value.
longincrementAndGet()
Atomically increments by one the current value.
intintValue()
voidlazySet(long newValue)
Eventually sets to the given value.
longlongValue()
voidset(long newValue)
Sets to the given value.
StringtoString()
Returns the String representation of the current value.
booleanweakCompareAndSet(long expect, long update)
Atomically sets the value to the given updated value if the current value {@code ==} the expected value.

Constructor Detail

AtomicLong

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

Parameters: initialValue the initial value

AtomicLong

public AtomicLong()
Creates a new AtomicLong with initial value {@code 0}.

Method Detail

addAndGet

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

Parameters: delta the value to add

Returns: the updated value

compareAndSet

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

decrementAndGet

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

Returns: the updated value

doubleValue

public double doubleValue()

floatValue

public float floatValue()

get

public final long get()
Gets the current value.

Returns: the current value

getAndAdd

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

Parameters: delta the value to add

Returns: the previous value

getAndDecrement

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

Returns: the previous value

getAndIncrement

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

Returns: the previous value

getAndSet

public final long getAndSet(long newValue)
Atomically sets to the given value and returns the old value.

Parameters: newValue the new value

Returns: the previous value

incrementAndGet

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

Returns: the updated value

intValue

public int intValue()

lazySet

public final void lazySet(long newValue)
Eventually sets to the given value.

Parameters: newValue the new value

Since: 1.6

longValue

public long longValue()

set

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

Parameters: newValue the new value

toString

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

Returns: the String representation of the current value.

weakCompareAndSet

public final boolean weakCompareAndSet(long expect, long update)
Atomically sets the value 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: expect the expected value update the new value

Returns: true if successful.