com.bluegosling.concurrent.contended

Class ContendedLong

java.lang.Object

com.bluegosling.concurrent.contended.ContendedLong

@IsDerivedFrom(value=java.util.concurrent.atomic.AtomicLong.class)
public class ContendedLong
extends Object

Like an AtomicLong, except uses padding to reduce cache contention (aka false-sharing) with writes to nearby memory locations.

Constructor Summary

Constructors

Constructor and Description
ContendedLong() Creates a new ContendedLong with initial value 0.
ContendedLong(long initialValue) Creates a new ContendedLong with the given initial value.

Method Summary

Modifier and Type	Method and Description
long	accumulateAndGet(long x, LongBinaryOperator accumulatorFunction) Atomically updates the current value with the results of applying the given function to the current and given values, returning the updated value.
long	addAndGet(long delta) Atomically adds the given value to the current value.
boolean	compareAndSet(long expect, long update) Atomically sets the value to the given updated value if the current value == the expected value.
long	decrementAndGet() Atomically decrements by one the current value.
long	get() Gets the current value.
long	getAndAccumulate(long x, LongBinaryOperator accumulatorFunction) Atomically updates the current value with the results of applying the given function to the current and given values, returning the previous value.
long	getAndAdd(long delta) Atomically adds the given value to the current value.
long	getAndDecrement() Atomically decrements by one the current value.
long	getAndIncrement() Atomically increments by one the current value.
long	getAndSet(long newValue) Atomically sets to the given value and returns the old value.
long	getAndUpdate(LongUnaryOperator updateFunction) Atomically updates the current value with the results of applying the given function, returning the previous value.
long	incrementAndGet() Atomically increments by one the current value.
void	lazySet(long newValue) Eventually sets to the given value.
void	set(long newValue) Sets to the given value.
String	toString() Returns the String representation of the current value.
long	updateAndGet(LongUnaryOperator updateFunction) Atomically updates the current value with the results of applying the given function, returning the updated value.
boolean	weakCompareAndSet(long expect, long update) Atomically sets 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, wait, wait, wait

Constructor Detail

ContendedLong

public ContendedLong(long initialValue)

Creates a new ContendedLong with the given initial value.

Parameters:

initialValue - the initial value

ContendedLong

public ContendedLong()

Creates a new ContendedLong with initial value 0.

Method Detail

get

public final long get()

Gets the current value.

Returns:

the current value

set

public final void set(long newValue)

Sets to the given value.

Parameters:

newValue - the new value

lazySet

public final void lazySet(long newValue)

Eventually sets to the given value.

Parameters:

newValue - the new 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

compareAndSet

public final boolean compareAndSet(long expect,
                                   long update)

Atomically sets 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 sets 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

See Also:

AtomicLong.weakCompareAndSet(long, long)

getAndIncrement

public final long getAndIncrement()

Atomically increments by one the current value.

Returns:

the previous value

getAndDecrement

public final long getAndDecrement()

Atomically decrements by one the current value.

Returns:

the previous 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

incrementAndGet

public final long incrementAndGet()

Atomically increments by one the current value.

Returns:

the updated value

decrementAndGet

public final long decrementAndGet()

Atomically decrements by one the current value.

Returns:

the updated value

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

getAndUpdate

public final long getAndUpdate(LongUnaryOperator updateFunction)

Atomically updates the current value with the results of applying the given function, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.

Parameters:

updateFunction - a side-effect-free function

Returns:

the previous value

updateAndGet

public final long updateAndGet(LongUnaryOperator updateFunction)

Atomically updates the current value with the results of applying the given function, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.

Parameters:

updateFunction - a side-effect-free function

Returns:

the updated value

getAndAccumulate

public final long getAndAccumulate(long x,
                                   LongBinaryOperator accumulatorFunction)

Atomically updates the current value with the results of applying the given function to the current and given values, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value as its first argument, and the given update as the second argument.

Parameters:

x - the update value

accumulatorFunction - a side-effect-free function of two arguments

Returns:

the previous value

accumulateAndGet

public final long accumulateAndGet(long x,
                                   LongBinaryOperator accumulatorFunction)

Atomically updates the current value with the results of applying the given function to the current and given values, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value as its first argument, and the given update as the second argument.

Parameters:

x - the update value

accumulatorFunction - a side-effect-free function of two arguments

Returns:

the updated value

toString

public String toString()

Returns the String representation of the current value.

Overrides:

toString in class Object

Returns:

the String representation of the current value