java.util.concurrent.atomic
Class AtomicBoolean

java.lang.Object
  java.util.concurrent.atomic.AtomicBoolean

All Implemented Interfaces:

java.io.Serializable

public class AtomicBoolean

extends java.lang.Object

implements java.io.Serializable

An AtomicBoolean maintains a boolean 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

AtomicBoolean()
Creates a new AtomicBoolean with initial value false.

AtomicBoolean(boolean initialValue)
Creates a new AtomicBoolean with the given initial value.

Method Summary

boolean	compareAndSet(boolean expect, boolean update) Atomically sets the value to the given update value if the current value is equal to the expected value.
boolean	get() Returns the current value.
boolean	getAndSet(boolean newValue) Sets to the given value and returns the previous value.
void	set(boolean newValue) Unconditionally sets to the given value.
boolean	weakCompareAndSet(boolean expect, boolean 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

AtomicBoolean

public AtomicBoolean(boolean initialValue)

Creates a new AtomicBoolean with the given initial value.

Parameters:

initialValue - the initial value

AtomicBoolean

public AtomicBoolean()

Creates a new AtomicBoolean with initial value false.

Method Detail

get

public final boolean get()

Returns the current value.

Returns:

the current value

compareAndSet

public final boolean compareAndSet(boolean expect,
                                   boolean update)

Atomically sets the value to the given update value if the current value is equal to the expected value. Any given invocation of this operation may fail (return false) spuriously, but repeated invocation when the current value holds the expected value and no other thread is also attempting to set the value will eventually succeed.

Parameters:

expect - the expected value

update - the new value

Returns:

true if successful

weakCompareAndSet

public boolean weakCompareAndSet(boolean expect,
                                 boolean 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.

set

public final void set(boolean newValue)

Unconditionally sets to the given value.

Parameters:

newValue - the new value

getAndSet

public final boolean getAndSet(boolean newValue)

Sets to the given value and returns the previous value.

Parameters:

newValue - the new value

Returns:

the previous value