Class AtomicBoolean

java.lang.Object
java.util.concurrent.atomic.AtomicBoolean
All Implemented Interfaces:
Serializable
public class AtomicBoolean extends Object implements Serializable
A boolean value that may be updated atomically. See the VarHandle specification for descriptions of the properties of atomic accesses. An AtomicBoolean is used in applications such as atomically updated flags, and cannot be used as a replacement for a Boolean.
Since:
1.5
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    AtomicBoolean()
    Creates a new AtomicBoolean with initial value false.
    AtomicBoolean(boolean initialValue)
    Creates a new AtomicBoolean with the given initial value.

  • Method Summary

    Modifier and Type
    Method
    Description
    final boolean
    compareAndExchange(boolean expectedValue, boolean newValue)
    Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchange(Object...).
    final boolean
    compareAndExchangeAcquire(boolean expectedValue, boolean newValue)
    Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchangeAcquire(Object...).
    final boolean
    compareAndExchangeRelease(boolean expectedValue, boolean newValue)
    Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchangeRelease(Object...).
    final boolean
    compareAndSet(boolean expectedValue, boolean newValue)
    Atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.compareAndSet(Object...).
    final boolean
    get()
    Returns the current value, with memory effects as specified by VarHandle.getVolatile(Object...).
    final boolean
    getAcquire()
    Returns the current value, with memory effects as specified by VarHandle.getAcquire(Object...).
    final boolean
    getAndSet(boolean newValue)
    Atomically sets the value to newValue and returns the old value, with memory effects as specified by VarHandle.getAndSet(Object...).
    final boolean
    getOpaque()
    Returns the current value, with memory effects as specified by VarHandle.getOpaque(Object...).
    final boolean
    getPlain()
    Returns the current value, with memory semantics of reading as if the variable was declared non-volatile.
    final void
    lazySet(boolean newValue)
    Sets the value to newValue, with memory effects as specified by VarHandle.setRelease(Object...).
    final void
    set(boolean newValue)
    Sets the value to newValue, with memory effects as specified by VarHandle.setVolatile(Object...).
    final void
    setOpaque(boolean newValue)
    Sets the value to newValue, with memory effects as specified by VarHandle.setOpaque(Object...).
    final void
    setPlain(boolean newValue)
    Sets the value to newValue, with memory semantics of setting as if the variable was declared non-volatile and non-final.
    final void
    setRelease(boolean newValue)
    Sets the value to newValue, with memory effects as specified by VarHandle.setRelease(Object...).
    String
    toString()
    Returns the String representation of the current value.
    boolean
    weakCompareAndSet(boolean expectedValue, boolean newValue)
    Deprecated.
    This method has plain memory effects but the method name implies volatile memory effects (see methods such as compareAndExchange(boolean, boolean) and compareAndSet(boolean, boolean)).
    final boolean
    weakCompareAndSetAcquire(boolean expectedValue, boolean newValue)
    Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetAcquire(Object...).
    boolean
    weakCompareAndSetPlain(boolean expectedValue, boolean newValue)
    Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetPlain(Object...).
    final boolean
    weakCompareAndSetRelease(boolean expectedValue, boolean newValue)
    Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetRelease(Object...).
    final boolean
    weakCompareAndSetVolatile(boolean expectedValue, boolean newValue)
    Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSet(Object...).

    Methods declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
    boolean
    equals(Object o)
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    int
    hashCode()
    Answers an integer hash code for the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

  • Constructor Details

    • 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 Details

    • get

      public final boolean get()
      Returns the current value, with memory effects as specified by VarHandle.getVolatile(Object...).
      Returns:
      the current value

    • compareAndSet

      public final boolean compareAndSet(boolean expectedValue, boolean newValue)
      Atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.compareAndSet(Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful. False return indicates that the actual value was not equal to the expected value.

    • weakCompareAndSet

      @Deprecated(since="9") public boolean weakCompareAndSet(boolean expectedValue, boolean newValue)
      Deprecated.
      This method has plain memory effects but the method name implies volatile memory effects (see methods such as compareAndExchange(boolean, boolean) and compareAndSet(boolean, boolean)). To avoid confusion over plain or volatile memory effects it is recommended that the method weakCompareAndSetPlain(boolean, boolean) be used instead.
      Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetPlain(Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      See Also:

    • weakCompareAndSetPlain

      public boolean weakCompareAndSetPlain(boolean expectedValue, boolean newValue)
      Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetPlain(Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9

    • set

      public final void set(boolean newValue)
      Sets the value to newValue, with memory effects as specified by VarHandle.setVolatile(Object...).
      Parameters:
      newValue - the new value

    • lazySet

      public final void lazySet(boolean newValue)
      Sets the value to newValue, with memory effects as specified by VarHandle.setRelease(Object...).
      Parameters:
      newValue - the new value
      Since:
      1.6

    • getAndSet

      public final boolean getAndSet(boolean newValue)
      Atomically sets the value to newValue and returns the old value, with memory effects as specified by VarHandle.getAndSet(Object...).
      Parameters:
      newValue - the new value
      Returns:
      the previous 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

    • getPlain

      public final boolean getPlain()
      Returns the current value, with memory semantics of reading as if the variable was declared non-volatile.
      Returns:
      the value
      Since:
      9

    • setPlain

      public final void setPlain(boolean newValue)
      Sets the value to newValue, with memory semantics of setting as if the variable was declared non-volatile and non-final.
      Parameters:
      newValue - the new value
      Since:
      9

    • getOpaque

      public final boolean getOpaque()
      Returns the current value, with memory effects as specified by VarHandle.getOpaque(Object...).
      Returns:
      the value
      Since:
      9

    • setOpaque

      public final void setOpaque(boolean newValue)
      Sets the value to newValue, with memory effects as specified by VarHandle.setOpaque(Object...).
      Parameters:
      newValue - the new value
      Since:
      9

    • getAcquire

      public final boolean getAcquire()
      Returns the current value, with memory effects as specified by VarHandle.getAcquire(Object...).
      Returns:
      the value
      Since:
      9

    • setRelease

      public final void setRelease(boolean newValue)
      Sets the value to newValue, with memory effects as specified by VarHandle.setRelease(Object...).
      Parameters:
      newValue - the new value
      Since:
      9

    • compareAndExchange

      public final boolean compareAndExchange(boolean expectedValue, boolean newValue)
      Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchange(Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      the witness value, which will be the same as the expected value if successful
      Since:
      9

    • compareAndExchangeAcquire

      public final boolean compareAndExchangeAcquire(boolean expectedValue, boolean newValue)
      Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchangeAcquire(Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      the witness value, which will be the same as the expected value if successful
      Since:
      9

    • compareAndExchangeRelease

      public final boolean compareAndExchangeRelease(boolean expectedValue, boolean newValue)
      Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle.compareAndExchangeRelease(Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      the witness value, which will be the same as the expected value if successful
      Since:
      9

    • weakCompareAndSetVolatile

      public final boolean weakCompareAndSetVolatile(boolean expectedValue, boolean newValue)
      Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSet(Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9

    • weakCompareAndSetAcquire

      public final boolean weakCompareAndSetAcquire(boolean expectedValue, boolean newValue)
      Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetAcquire(Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9

    • weakCompareAndSetRelease

      public final boolean weakCompareAndSetRelease(boolean expectedValue, boolean newValue)
      Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle.weakCompareAndSetRelease(Object...).
      Parameters:
      expectedValue - the expected value
      newValue - the new value
      Returns:
      true if successful
      Since:
      9